Bat Tree Habitat 2nd Edition 2013 by james chadwick

BAT TREE HABITAT KEY ___________________________________________________________________________ Please Reference as: Andrews H et al. 2013. Bat Tree Habitat Key. AEcol, Bridgwater. ___________________________________________________________________________

CONTENTS PREFACE ACKNOWLEDGEMENTS TREES A1. INTRODUCTION A2. TREES – BIOLOGY FOR BAT-WORKERS 2.1 2.2 2.3 2.4

General ................................................................................................................................. Definition ............................................................................................................................. Growth & Development ..................................................................................................... Why Tree Biology Matters to Bats ....................................................................................

1 2 2 4

A3. TREES – DECAY & DEFENCE 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10

General ................................................................................................................................. Infection ............................................................................................................................... Wood-Rot Fungi ................................................................................................................. White-Rots .......................................................................................................................... Brown-Rots .......................................................................................................................... Defence................................................................................................................................. Compartmentalisation of Decay in Trees (CODIT) ......................................................... CODIT Lines of Defence .................................................................................................... How CODIT Works ............................................................................................................ Why Decay & Defence Matters to Bats ............................................................................

1 1 1 2 3 5 5 10 12 16

A4. TREES – DECAY PRF 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

General ................................................................................................................................. Woodpecker-Holes .............................................................................................................. Knot-Holes ........................................................................................................................... Flush-Cuts ............................................................................................................................ Tear-Outs ............................................................................................................................. Double-Leaders ................................................................................................................... Wounds & Cankers ............................................................................................................ Butt-Rots ..............................................................................................................................

1 2 7 11 13 19 28 33

A5. TREES – DAMAGE & REPAIR 5.1 Damage ................................................................................................................................. 1 5.2 Repair ................................................................................................................................... 3 5.3 Why Damage & Repair Matters to Bats ........................................................................... 4

A6. TREES – DAMAGE PRF

6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9

General ................................................................................................................................. Hazard-Beams ..................................................................................................................... Frost-Cracks ........................................................................................................................ Subsidence, Shearing & Helical-Splits .............................................................................. Lightning-Strikes ................................................................................................................ Impact-Shatters ................................................................................................................... Dessication-Fissures ............................................................................................................ Transverse-Snaps ................................................................................................................ Lifting-bark .........................................................................................................................

1 1 7 13 16 17 19 21 23

A7. TREES – DIVISIONS 7.1 General ................................................................................................................................. 1 7.2 Divisions ............................................................................................................................... 1 7.3 Why Tree Divisions Matters to Bats ................................................................................. 3

A8. TREES – HABITAT 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8

General ................................................................................................................................. Introduction ......................................................................................................................... The Tree as an Individual Entity ....................................................................................... Where Trees Are Found ..................................................................................................... Parks, Hedges & Commons ............................................................................................... Woods ................................................................................................................................... Plantations ........................................................................................................................... Why Habitat Matters to Bats .............................................................................................

1 1 6 7 7 10 13 16

A9. TREES – WOOD 9.1 9.2 9.3 9.4 9.5 9.6

General ................................................................................................................................. Heartwood ........................................................................................................................... Ripewood ............................................................................................................................. Sapwood ............................................................................................................................... Biological Natural Durability ............................................................................................ Why Wood Matters to Bats ................................................................................................

1 3 4 5 6 6

A10. TREES – ASSOCIATION PRF 10.1 General ................................................................................................................................. 1 10.2 Unions .................................................................................................................................. 1 10.3 Ivy Hedera helix .................................................................................................................. 4

TREE-ROOSTING BATS TREE-ROOSTING BATS – A WOODLAND BAT SPECIES LITERATURE REVIEW

B1. 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8

General ................................................................................................................................. Barbastelle Barbastella barbastellus ................................................................................. Bechstein’s bat Myotis bechsteinii ..................................................................................... Brandt’s bat Myotis brandtii ............................................................................................. Daubenton’s bat Myotis daubentonii ................................................................................ Natterer’s bat Myotis nattereri .......................................................................................... Leisler’s bat Nyctalus leisleri ............................................................................................. Noctule Nyctalus noctula ....................................................................................................

1 2 9 12 14 19 24 29

1.9 1.10 1.11 1.12 1.13 1.14

Pipistrellus spp. ................................................................................................................... Nathusius’ pipistrelle Pipistrellus nathusii ........................................................................ Common pipistrelle Pipistrellus pipistrellus .................................................................... Soprano pipistrelle Pipistrellus pygmaeus ......................................................................... Brown long-eared bat Plecotus auritus ............................................................................. Miscellaneous Accounts of Exceptional Tree-Roost Use .................................................

34 35 38 41 43 48

B2. TREE-ROOSTING BATS – COMPETITORS & PREDATORS 2.1 2.2 2.3 2.4

General ................................................................................................................................. Invertebrates ....................................................................................................................... Birds ..................................................................................................................................... Mammals .............................................................................................................................

1 1 8 12

B3. TREE-ROOSTING BATS – MAPPING PRF 3.1 3.2 3.3 3.4

General ................................................................................................................................. Mapping Objective .............................................................................................................. Mapping Equipment ........................................................................................................... Mapping Method .................................................................................................................

1 2 2 2

B4. TREE-ROOSTING BATS – TREE-ROOST FIELD-SIGNS 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Introduction ......................................................................................................................... Living or Dead Bats ............................................................................................................ Scratches Around the Edge of a PRF ................................................................................ Smoothing/Polishing of Surfaces Around a Potential Entrance ..................................... Urine Staining Below a PRF .............................................................................................. Bat-Droppings ..................................................................................................................... Audible Squeaking .............................................................................................................. Flies Buzzing Around a PRF .............................................................................................. Distinctive Smell of Bats or Ammonia .............................................................................. Accumulation of Prey Debris .............................................................................................

1 2 3 3 6 8 8 10 10 11

B5. TREE-ROOSTING BATS – INSPECTING & ASSESSING PRF 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9

Introduction ......................................................................................................................... General ................................................................................................................................. Legal Considerations .......................................................................................................... Health & Safety ................................................................................................................... Inspection Objective ........................................................................................................... Inspection Equipment ......................................................................................................... Inspection Method .............................................................................................................. Timing .................................................................................................................................. PRF Assessment ..................................................................................................................

1 2 3 3 4 4 5 16 22

B6. TREE-ROOSTING BATS – BAT TREE HABITAT KEY 6.1 6.2 6.3 6.4 6.5 6.6 6.7

Introduction ......................................................................................................................... Key Glossary ........................................................................................................................ General Key ......................................................................................................................... Key A – Woodland Trees ................................................................................................... Key B - Riparian ................................................................................................................. Key C - Hedgerow ............................................................................................................... Key D – Isolated Trees ........................................................................................................

REFERENCES

1 2 3 3 34 60 71

PREFACE 2nd Edition This text began life purely as an instruction manual to allow field-testers to process potential tree-roost features through a dichotomous habitat key. However, in response to feedback I have received from field-testers in Bat Groups across the UK, I have now enlarged it to form this guide. This text encompasses more or less all I understand about how Potential Roost Features form, why they form, where they form, why they form where they form and approximately how long they can be predicted to last. I would however like to take this opportunity to make you aware of three facts: 1. I am not an expert on bats or trees; 2. This text isn’t a finished product but a work in progress; and 3. The text will only make sense if you spend time in the field looking for yourself. In his 1921 Text-book of Wood Herbert Stone opened by saying “…I am a compiler, and I am not ashamed of the name…” I too am a compiler. I have sought out rare volumes, attended a good few courses, interrogated experts, listened to the amateurs, and searched miles of woodland, park, hedgerow and farmland in order that I might compile all the useful information I found. It is my hope that “…in sifting many a heap of millet-seed in which there was after all, no pearl, I have done the English reader good service” (Stone 1921). However, as I said earlier, the text is far from complete; there is more to learn than is currently known and there is still more to be read and interpreted. As a result, it appears to me that the internet is the obvious home for this document, as by keeping it as a free web-hosted PDF it can be updated and enlarged each year. In my more fanciful hours I see it as a ‘wikitreedia’ which can be enlarged by anyone with a snippet of information. I hope you will join me in my search for knowledge as an active participant, find roosts yourselves, record them, and send in your experiences for inclusion. Everything I am sent will be reviewed added into the text and, where appropriate, used to refine the key. I will update the text every year as new information comes to light or until something better supersedes it. In addition, if you have any questions, you can email me at henry.andrews@aecol.co.uk. I cannot promise I will be able to answer them, but I can promise that if I can’t I’ll do my best to find someone who can. Ultimately I wrote this text because no-one else had. It is my hope that it is of some benefit to others out there who are as keen to learn as I am. Henry Andrews, January 2013

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BAT TREE HABITAT KEY – ACKNOWLEDGEMENTS 2013 I would like to thank the following people for their contributions of knowledge and for their input and guidance in this updated and enlarged text: Dr Geoff Billington (Director, Greena Ecological Consultancy), for providing a massive body of barbastelle data, Dr Johnny Birks (Chairman, The Mammal Society) & Dr Marian Bond (Editor, Mammal News) for their help in publicising the Key and appealing for field-testers, Cindy Blamey (Woodkeeper of Highgate Wood, north London) who sent over all her tree-roost photographs and provided useful accounts of the numerous roosts she has found, the mysterious Antony Croft (alias Hamadryad), who provided some truly beautiful photographs of a noctule maternity colony in an ash canker and then vanished, David Dowse (Senior Ecologist, Heritage Environmental Ltd), who sent on all his tree-roost photographs and is to my knowledge the only person in the British Isles ever to photograph a pipistrelle in a tree-roost, John Haddow (Director, Auritus Consultancy Ltd) & Stuart Spray (Director, Stuart Spray Wildlife Consultancy), who together are the driving force behind the Scottish Leisler’s Project, Richard Koczy (Case Officer, Scottish Natural Heritage), who provided the photographs and account of a soprano pipistrelle hibernation roost in a Douglas Fir, Dr Garry Mortimer (Director, GLM Ecology) who provided an account of his unique experiences of Natterer’s bats roosting within double-leader Corsican pines, Dr Jon Russ (iBats Coordinator, Bat Conservation Trust) for arranging for the Key to be brought to widespread attention by Bat Groups across the British Isles, Lisa Worledge (Partnerships Officer, Bat Conservation Trust), who provided encouraging emails and forwarded on my begging correspondence to several useful contacts, Anne Youngman (Scottish Bat Officer, Bat Conservation Trust), who provided everything she had to hand on tree-roosts in Scotland and provided the contact details of a good many people who contributed valuable information. In addition I wish to acknowledge the following people for contributing their scientific knowledge, field experience, help, encouragement and guidance during this project: John Andrews (Director, AEcol), George Bemment (Director, George Bemment Associates), Peter Brash (Ecologist, National Trust), Matt Dodds (North Bucks Bat Group), Neil Hairsine (Director, NPH Ecology), Daniel Hargreaves (Trinibats Project), John Kaczanow (Director, John Kaczanow Ecology), Mark Latham (Lead Advisor, Natural England), Theresa Radcliffe (long-suffering partner), Tom Staton (Senior Ecologist, Aspect Ecology) and), Dr Jackie Underhill (Director, Jackie Underhill ecology) Steve Wadley (Director, Monmouth Tree Services), Keith Zealand (Sheringham Park Manager, National Trust). In particular I would like to thank Neil ‘Bees! Bees! Bloody bees!’ Hairsine for being on hand to climb a huge number of trees, always with good humour and enthusiasm, in the early days of this project.

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BAT TREE HABITAT KEY

INTRODUCTION Chapter A1 – Trees – Introduction 2013 __________________________________________________________________________________________

INTRODUCTION - 2013 I would like to begin by stating a fact: British tree-roosting bats do not make the features in the trees in which they roost. All the species of tree-roosting bats recorded in the UK, native or vagrant, are dependent upon a combination of the right species of tree, in the right place, being exposed to the right set of conditions, to cause the formation of the right roost-feature. The bats themselves are irrelevant in this process. Despite this fact, research into tree-roosting bat ecology has historically side-lined the trees themselves into a subordinate role. Whilst a tree species list might be given within published accounts of tree-roosting ecology and white-papers, sometimes they don’t even get that. In fact, even the bat-roost features themselves are seldom given detailed descriptions. Most published accounts of tree-roosts are vague, photographs are either entirely absent or (due to the cameras that were available at the time) only show the roost entrance from a distance. As a result, when I began looking for tree-roosts I didn’t know what the external appearance of a suitable roost feature looked like. Furthermore, although I was unaware at the time, I was working from a palette of confused field-signs. I was therefore spending a good deal of time looking in the wrong places, at the wrong features and typically guided by the wrong fieldsigns; little wonder I became frustrated and demoralised and eventually stopped looking altogether. Then in the space of a month I had two ‘Eureka!’ moments. The first came to me while reading Ramsbottom’s New Naturalist Mushrooms & Toadstools 1953). Mr Ramsbottom suggests that “The reputed rarity of a species is probably nothing more than an ignorance of its habitat.” This was a fair comment, but I thought at the time; if you’re ignorant of a species habitat then you can’t search for it. Then, a couple of days later I was working in a brown long-eared bat Plecotus auritus roost in a roof-void and I thought to myself “if the bats are roosting in the roof apex against the ridge-beam, what tree feature would replicate those conditions?”. I bought a couple of books about trees and found a description of ‘hazard-beams’ which fitted the characteristics of the roof-void location. The following weekend I went out and found some hazard-beams and hey-presto two brown long-eared tree-roosts, and two more followed in quick succession (one the same day in fact); thank you Mr Ramsbottom. So rather than walking about blindly in an ignorant haze of what I didn’t know, I started to piece together what I did know about the roosting habits of bats and (in particular) focussed my attention on the sort of shapes individual species occupy in houses, to try and find which shapes closely matched them in trees. This led me to my second Eureka moment. When I read up on how trees work and how Potential Roost Features (PRF) form. This made me think about which PRF typically form in which tree species, why, and in which habitat. My knowledge was still very rough and rudimentary, but it did enable me to begin to target __________________________________________________________________________________________ A1 - 1

BAT TREE HABITAT KEY

INTRODUCTION Chapter A1 – Trees – Introduction 2013 __________________________________________________________________________________________

effort to look for the right PRF in the right habitat. By looking first for the trees and the features, I began finding more and more bat-roosts. Looking at it all now this breakthrough appears somewhat ‘Zen’; finding the bats by no longer looking for them. When you can’t see the bats for the trees, isn’t it more sensible to look first at the trees and the PRF they hold?

“When I pass over the bridge, lo, the water flows not; it is the bridge that flows…” Excerpt of a poem attributed to the T’ang Dynasty

Interestingly perhaps, it would appear that I have not been alone in my frustration. Until last year when Dietz & Pir (2011) identified the physical features the Bechstein’s bats Myotis bechsteinii in their study were occupying (even going so far as to define exactly which woodpeckers made the woodpecker holes), no study I had found identified the forms of the features the bats were roosting in using recognisable arboricultural terms. This has left arborist’s confused and unable to relate the vague descriptions in studies of roosting ecology with their accepted nomenclature; if you tell an arborist that hibernating barbastelle Barbastella barbastellus favour horizontal splits he’ll give you a blank look, but tell him that they favour horizontal ‘hazard-beams’ and he’ll tell you where there are five. Tell a forester that male bats of several species favour vertical splits and he’ll give you a blank look, but tell him they favour frost-cracks and he’ll take you to the frost hollow, and you can count the roosts yourself. In fact every subtly different feature you see on a tree has been named by woodsmen, foresters and arboriculturalists, from ‘bottle-butt’ through ‘frost-crack’, ‘canker’, ‘doubleleader’, ‘knot-hole’, ‘tear-out’ and ‘hazard-beam’, and in the last ten years their attributes have been described and illustrated in eminently readable text-books by, amongst others, our own Forestry Commission. Furthermore, those tree-features very often bare an uncanny resemblance to the features the individual bat species are often found using on, and in, houses. I have come to the conclusion to become proficient in finding tree-roosts you need to know a good deal more about trees than you do about bats. I have therefore divided this updated and enlarged text into two parts:1. TREES; and 2. TREE-ROOSTING BATS. The idea is to try and begin piecing together an understanding the individual (and apparently unrelated) mechanisms that must combine to form the features individual bat species favour. I hope that by gaining a deeper insight into these processes, it will be possible to define a method that will focus on the most important field-signs, and use visual habitat clues (habitat, gradient, substrate, fungal fruit-bodies etc.) in order to target effort in the most effective way. It should also and prompt/support more detailed surveys, even when the PRF are not obvious from the ground. __________________________________________________________________________________________ A1 - 2

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INTRODUCTION Chapter A1 – Trees – Introduction 2013 __________________________________________________________________________________________

In order to begin imbuing the reader in the various subtle mechanisms involved in PRF formation, I have plundered the available texts in order to provide a description of how trees work and PRF form in plain language. Then, and only then, have I moved on to the bats, by again plundering every available text in order to provide descriptions of how our treeroosting species use trees. Each account in identical format, and what is unknown (or at least unpublished) is also presented. Finally, drawing from my own experiences I have suggested methods for: how to look for tree-roosts;  when to look for tree-roosts; and  what to record, whether bats are present or not, because in these early days of research negative results are every bit as important as positive results. I have written this text because no text setting out a field-craft method for finding tree-roosts has been written to date. It’s all I know; a good deal I have finally taken the time to confirm from higher sources, and some entirely new information that I had been entirely unaware of prior to writing the first draft, but have been given by a host of Bat Workers across England and Scotland. I hope the text represents a robust baseline of readily applied information and field-craft but: IT IS A WORK IN PROGRESS. The text is therefore divided into individual sub-sections in order that interested parties may download all this year, but need only download updated sections from then on. Some sections are likely to remain more or less as they are now, others will doubtless be fluid for some considerable time. Whilst the text represents all I know, it is by far all that there is to know. I firmly believe that all the compilation of this text has achieved, is to expose the capstone of the pyramid; the best is yet to come! By encouraging everyone to begin speaking the same language, I hope that naturalists, ecologists, arborists, arboriculturalists, woodsmen and foresters can begin to share their knowledge in an open forum to their mutual benefit, but more importantly to the benefit of of our native bat species. To add a hint of drama I will close this introduction with a warning: “Facile adaptationist guesswork used to explain everything that we observe in nature scarcely serves to make ecology an effective medium for teaching the principles of science.” J.L. Harper, 1982. I am mindful of this observation (which I admit I lifted from Rackham (2006)) and would therefore emphasise that whilst I have included hypotheses of my own to suggest potential reasons for things I have seen etc., these are set apart in boxes, because I have no conclusive evidence myself, am therefore uncertain, and cannot find anything from another source that will confirm or contradict my musings. ______________________________

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Section A. TREES Chapter A2 – Trees – Biology for Bat-Workers __________________________________________________________________________________________

TREES –BIOLOGY FOR BAT-WORKERS GENERAL At the time of writing, the seventeen known PRF fall into three categories:  Decay (often facilitated by structural damage) which comprises: o Woodpecker-holes; o Knot-holes; o Flush-cuts; o Tear-outs; o Double-leaders; o Wounds & cankers; and o Butt-rot.  Damage, which comprises: o Hazard-beams; o Frost-cracks; o Subsidence, Shearing and Helical-splits o Lightning strike; o Impact shatters; o Desiccation fissures; o Transverse snaps; and o Lifting bark.  Associations, which comprise: o Unions; and o Ivy. For many readers the technical names of PRF will be unfamiliar but do not despair, a journey of 1,000 miles starts with a single step, and I hope that the following chapters will provide sufficient information for you not only to become familiar with the names, but also have a basic understanding of what the names actually mean. For now all you need to know is that all three categories and theie 17 individual PRF have something in common, and that is the trees in which, or on which, they occur. Even those naturalists who don’t have any particular botanical interest can usually identify the UK’s native trees, but how many of us really get to grips with how trees work? I certainly hadn’t when I wrote the Bat-Tree-Habitat-Key or the first edition of this document. My objective in writing the first half of this text was therefore to try to gain a deeper understanding of what trees are, and why they form PRF in the way they do, or don’t; depending on the species, so I could search specific habitats in the most productive way, but focussing on the PRF they were most likely to hold. To illustrate; searches of coniferous plantation are likely to be more fruitful if you target your effort in the compartments of Corsican pine Pinus nigra, Larch Larix spp. and Douglas fir Pseudotsuga menziesii, and search specifically for Double-leaders and Butt-rots (If anything else is there, you’re likely to find it anyway). Conversely, if you’re searching the spruce compartments and looking for all the seventeen different forms of PRF, you’re likely to have a long and frustrating day. __________________________________________________________________________________________ A2 - 1

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Section A. TREES Chapter A2 – Trees – Biology for Bat-Workers __________________________________________________________________________________________

DEFINITION Stone (1921) defines a tree as “a long-lived woody plant of upright habit and single stem, having a capacity for indefinite growth”. Obviously we can all think of exceptions to this definition but, for most of us, this is what we think of when we hear the word tree. I make no excuses for using generalisations in this text. We were all ‘beginners’ once and needed some basic general foundations upon which to build (who among us is no longer learning?). In every aspect of the natural world there are ‘variations’ which confound the student (botanists will be well acquainted with the phrase “very variable…” from keys and species accounts). In order to recognise the anomaly, one first has to get the typical form committed to memory so firmly that one can recognise the subject even when it is distorted.

GROWTH & DEVELOPMENT Trees start life as a seed. In the first year of development the tree seed puts out one root downward and two or more leaves upward or, in the case of conifers, a little whorl of ‘needles’. Deciduous trees shed the leaves in the winter and the buds remain dormant until moderately late in spring (May onwards). When the days lengthen sufficiently, and temperatures rise, the seedling buds expand to put out embryo twigs, each of which holds a new series of leaves. In contrast, coniferous trees replace their needles more gradually; retaining more than one whorl of leaves; the current year's and the previous year’s as a minimum (Watson 2006). In the second year of development a coniferous tree will add to its existing complement of needles, and from then on replace the older needles on a rolling basis. As winter gives way to spring, seedling trees (both broadleaved and coniferous) continue their upward growth. In addition the stems (don’t call it a ‘trunk’ folks, it’s a stem) grow broader. This increase in diameter occurs just below the bark in the ‘cambium’ (Thomas 2000). The cambium is the living tissue (Thomas 2000); a thin jelly-like layer between the bark and the previous year’s wood enveloping the stem and branches (Desch & Dinwoodie 1996, Thomas 2000). In the winter months the cambium sleeps as a single layer of cells, but in spring it wakes and the cells subdivide growing outwards to form a layer of eight to ten cells in width, stretching the bark and enlarging the tree over its entire surface, including the roots (Desch & Dinwoodie 1996, Edlin 1944). This is the first ‘annual-ring’. Around the slender core of pith successive annual-rings of conductive tissue will form each spring so that as the stem elongates, so do its channels of nourishment enlarge to feed it, from the foliage to the roots (Edlin 1944). I’m not going to go into any great depth with descriptions of cells and tissue yet, but will come back to some of their characteristics in Chapter 3 when looking more closely at the ways trees defend themselves against decay. For now, all the bat enthusiast needs to know is that, as with all other living things no matter how large, trees are made up from lots of tiny components called cells, packed in side by side but also stacked on top of each other.

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Section A. TREES Chapter A2 – Trees – Biology for Bat-Workers __________________________________________________________________________________________

In very broad terms these cells are not entirely self-contained, but have tiny openings above and below (and on sides), with some acting as the trees plumbing and others there simply to hold the whole thing up (Thomas 2000). However, coming back to our seedling, by the end of year two the vertical stem (or leader) is formed with lateral branches. At this stage, if a close inspection is made, it would be noted that the lower portion of the stem is slightly larger in diameter than the tip of the leader. This is due to the additional coat of wood enveloping the old stem, and continuing beyond it to form the new growth above (Stone 1921). The leader of the second year, being a new extension, has only a single layer of wood enclosing the pith (where now the first year has two) and is identical in structure to that of the first year, from the leader tip to the root tip (Edlin 1944). In fact, if you could withdraw the first-year’s tree from its new sheath of wood it would look like a twig stripped of its skin. Stone (1921) gives an account of a situation where during felling a tree was not cut right to the centre, and the prototype naked sapling was drawn out from the stem and left on the stump! I don’t know how accurate this is but it does illustrate the growth situation very clearly. I have provided an illustration at Figure A2.1, although I'm confident a ‘Russian doll’ analogy would have been sufficient.

Figure A2.1. The layered growth of a tree (Figure based on that of Kozlowski (1971)). __________________________________________________________________________________________ A2 - 3

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Section A. TREES Chapter A2 – Trees – Biology for Bat-Workers __________________________________________________________________________________________

In the winter much of the year’s new growth of cambium dies and the living cells again remain dormant until the next spring. This succession of new growth, expanding the tree outward and upward over each successive year of life, is what gives us the growth rings by which we tell the trees age. In mature specimens of thick-barked species (i.e. alder Alnus glutinosa, sweet chestnut Castanea sativa and pedunculate oak Quercus robur), the stretching of the bark causes deep fissures in the old bark tissue, whilst in thinner bark it may cause large flakes of lifting bark (i.e. London plane Platanus x hispanica, downy birch Betula pubescens) or slough in such small amounts it is barely noticeable (i.e. beech Fagus sylvatica). I have found large mature alders Alnus glutinosa where the bark had formed such deep fissures low on the stem and butt that I wondered if they were sufficiently in themselves deep to provide roosting opportunities for individual bats (see Figure A2.2). However, whilst the descriptions I have seen of bats roosting in bark were not accompanied by photographs, they suggest these were individual or low numbers of bats roosting under plates of dead bark; between the bark and the wood beneath rather than within fissures in live bark. While I have not yet found a bat roosting in such a bark fissure (nor indeed have I ever myself found a bark roost), this project is in its infancy and I have inspected too few large alders to draw any conclusions.

Figure A2.2. Deeply fissured bark on mature Alder Alnus glutinosa; a PRF in itself?

Growth continues in each successive year, with the stem increasing in diameter, height and depth annually; upward via a series of leaders one above the other; outward by a series of layers of wood, and downward via annually incremented sheaths of root tissue. The resulting stem, limbs and even the roots are therefore a series of elongated cones or tapering spires enclosed by the bark. To illustrate, if you cut across the stem horizontally you would see a series of concentric rings, but cut the stem vertically down the middle and instead of rings, you’d see a series of drawn out triangles (Stone 1921). This is important; the core of the stem and branches is a series of elongated cones, one on top of the other tapering up from a wide base into a spire.

WHY TREE BIOLOGY MATTERS TO BATS Ultimately the internal shape of many roost-features is defined by the trees inherent growth progression, and recognising this will help the beginner to search for potential roost sites far more objectively. Obviously this is not (as we’ll learn later) the whole story, but having some __________________________________________________________________________________________ A2 - 4

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understanding of the core structure of trees may perhaps begin to help explain why bats occupy some tree species, and some physical features within those trees, more often than others. I’m sure we can all accept the fact that larger groups of bats need a larger void so everyone can get in, but consideration also must be given to how they group. Dietz & Pir (2011) found that maternity colonies of Bechstein’s bats Myotis bechsteinii preferred a more obtuse ‘domed’ roost apex. In contrast, individual male Bechstein’s bats preferred a very acute spire in which to wedge themselves (Dietz & Pir 2011). This has also been the case with the greater percentage of individual bats I have found, comprising barbastelles Barbastella barbastellus, Daubenton’s bats Myotis daubentonii, Natterer’s bats M. nattereri, noctules Nyctalus noctula and brown long-eared bats Plecotus auritus (although I don’t know the sex), which were wedged so tightly into the roost apex that in many cases identification was difficult and relied upon ear and tragus shape alone. Just to confuse the issue, the two hibernating bats I have discovered (one brown long-eared and one noctule but again I’m afraid I don’t know the sex) were both in trees that had a tall and internal spire, but the bats were hanging well below the apex from the roost wall so they were free from the substrate around them (which was wet), and only their feet were in contact with the wood. The tree's inherent growth form gives it a predisposition for spire-like hollows, evident by the observations that decay originating from the roots tends to be concentrated in the centre of the tree and to form a cone (Cartwright & Findlay 1958). But if the growth of trees gives them a predisposition to tall and narrow spire-like cores, how do dome-shaped hollows form? Well, this is where we introduce the wider varieties of decay (and their associated agents; woodpeckers etc.) into the equation because, with the exception of Hazard-beams and Frostcracks, all other hollow roost features are either directly caused by the actions of woodrotting fungi, or at least made easier by their presence (again, think Woodpecker-holes) and, as we’ll learn later, these fungi attack different species of trees in different ways, and the trees themselves have varying levels of resistance.

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TREES – DECAY & DEFENCE GENERAL Of the 17 PRF types described in this text woodpecker holes, knot-holes, flush-cuts, tearouts, double-leaders, wounds & cankers and butt-rot all rely on decay fungi to varying extents for their formation, as timber does not deteriorate or ‘lose its nature’ by age alone (Cartwright & Findlay 1958). Many texts will tell you that the hollowing of older trees is part of the natural aging process, and when I first read this I had unconsciously accepted it without wondering why. In fact, this ‘natural ageing’ appears to me to be anything but; as hollows don’t just form by themselves, something devours the wood and that something is fungi, with the only other (and far lesser) agent being bacteria (Lonsdale 1999).

INFECTION Fungi may infect a tree via the root system or above ground. Major cases of heart-rot in the stem are usually found to have commenced from the base (Ackers 1938). Above ground, bark is a barrier to many fungal infections, but even in a relatively undisturbed woodland, bark may be damaged and/or lost due to environmental factors (i.e. frost-cracks, impact grazing from another falling tree, wind-throw tear-outs etc.), the attack of insects (wood-boring beetles etc.) and/or other animals (i.e. squirrels bark-stripping) (Cartwright & Findlay 1958). When the bark is penetrated airborne spores may enter. However, even where the spores penetrate the defences, they may not land in a hospitable germination zone; the fungus cannot become established unless there is sufficient moisture for germination of the spore and the external digestion of the wood substrate (Gallagher & Cahill 1995). Wounds in which the wood is scored or splintered are more likely to be successfully infected than a smooth skinning wound (Lonsdale 2000), but even then the fungal spores have to land on the right tree species as most (but not all) wood-rotting fungi are restricted to certain host species (Cartwright & Findlay 1958). If infection is successful, the fungi spreads through the tree via microscopically thin threads (known as hyphae) which penetrate through and between the cells, branching indefinitely as long as a food source is present (Spooner & Roberts 2005). That food source is wood, and wood-rotting fungi obtain their nutrition by secreting enzymes into the host wood in order to digest it externally, before absorbing it (Gallagher & Cahill 1995). As a result, fungi are the most destructive decay agents of wood (Spooner & Roberts 2005).

WOOD-ROT FUNGI Wood-rotting fungi can be divided into two principal camps; the saprobes which live off dead matter, and the parasites which live off live matter. A very few overlap, having the ability to cross from dead to live wood and back again, but this occurs only rarely and in unusual circumstances (Alexander 2011). When I began looking into the formation of PRF I assumed __________________________________________________________________________________________ A3 - 1

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all wood-rotting fungi were parasites, but in the greater percentage of cases, they are saprobes as (although they are surrounded by a live shell) the hearts of most large trees are technically more or less dead, with the cells simply acting as structural support and plumbing. These two categories can be further divided into where they typically occur on the tree; stem decay pathogens or root decay pathogens (Schwarze et al. 2000), and where a fungus typically occurs will have a bearing on the sort of PRF it forms (if any). This has a particular importance with the root decay pathogens, some of which remain almost completely within the roots (and are therefore of no value to bats) and others which also colonise the butt (Schwarze et al. 2000). I’m not going to go too deeply into the fungi themselves, and have only identified specific species which have known PRF associations. For those who wish to know more, I would recommend:  Lonsdale D 1999. Research for Amenity Trees No.7: Principles of Tree Hazard Assessment and Management. Forestry Commission, London: TSO;  Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer; and  Weber K & Mattheck C 2003. Manual of Wood Decays in Trees. Arboricultural Association, Gloucestershire.

There are four categories of fungal infection comprising:1. Sapstains; 2. Soft-rots; 3. White-rots; and 4. Brown-rots (Gallagher & Cahill 1995). Sapstains result in the discolouration of sapwood but cause little deterioration of the wood. Soft-rots (which may be confused with sapstains) are also not significant as pathogens of timber. Infection by Sapstains or Soft-rots does not result in the formation of PRF, so we don’t need to give them any further consideration and can instead focus all our scrutiny on white and brown-rots.

WHITE-ROTS White-rots behave in subtly different ways which can broadly be separated into two strategies:  Selective delignification; and  Simultaneous white-rots. The selective delignification white-rots destroy lignin; a brownish-red wax that gives wood cells structural strength, so only the white wood cellulose remains (Stone 1921), hence the name white-rot. Selective delignification often leaves the internal surfaces of cavities a chalky white, and gives the wood a ‘bleached’ appearance (see Figure A3.1). In some cases it leaves the wood soft enough to dent with a finger-tip (H. Andrews pers obs.), but structurally as it was before, although with a loss of much of its weight (Stone 1921). Where decay is confined to the central area of the woody cylinder, whilst it makes it easier for woodpeckers to excavate a nest cavity, it has little effect on the strength of the affected part of the tree but brings about a greater level of flexibility, to which the tree responds by laying down locally widened annual rings in that portion of the stem or limb (Lonsdale 1999). As a result, the __________________________________________________________________________________________ A3 - 2

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infected limb is often stabilised around the rot and may have significant longevity. This is readily apparent by the predilection for woodpeckers to excavate nest holes in trees infected with P. igniarius, P. robustus and Inonotus hispidus, all of which are selective delignification white-rot fungi, and the latter of which is one of the species that can switch between live and dead tissue (Schwarze et al. 2000).

Figure A3.1. A white-rot infected limb from a pedunculate oak Quercus robur (left) and a typical stringy and soft white-rot infected heartwood of pedunculate oak (right).

In contrast, simultaneous white-rots attack all the constituents of the wood including the lignin and cellulose, still leaving the wood bleached, but also stringy and soft (Cartwright & Findlay 1958, Spooner & Roberts 2005). This may continue until the wood substance is totally consumed leaving an empty cavity (Cartwright & Findlay 1958, Lonsdale 1999). Lonsdale (1999) suggests that white-rot bracket fungi (or polypores) are the fungi most associated with cavity formation within trees. This isn’t however because they white-rots decay faster than brown-rots, but because there are more white-rots, and they’re more widespread. White-rots are by far the most diverse group of wood-rotting fungi and, Schwarze et al. (2000) cites Gilbertson (1980) and Watling (1982) in stating that white-rots are more associated with broadleaved trees than conifers. In terms of longevity of white-rot PRF, white-rots may bring about a drop in the toughness of the wood, but less rapidly than brown-rots (Cartwright & Findlay 1958). Decay is often limited to a small area so that stability is not impaired (Schwarze et al. 2000).

BROWN ROTS In contrast to white-rots, brown-rot fungi break down the white cellulose alone, leaving the brown-red lignin and resulting in the rotten wood appearing orange to brown (see Figure __________________________________________________________________________________________ A3 - 3

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A3.2), cubically cracked, and powdery rather than stringy (Stone 1921, Cartwright & Findlay 1958, Spooner & Roberts 2005). Brown-rots are conspicuous by the orange-brown colouration of the infected wood which, due to shrinkage, often has a cubical appearance, with the wood split by transverse cracks into brick-shaped pieces (Gallagher & Cahill 1995). Lonsdale (2000) sets out that “the most dangerous form of decay is brittle decay, caused by fungi which degrade the rope-like cellulose content of wood (‘brown rot’)”. Where the whiterots typically break down the wood and leave it soft but still moderately strong, the brownrots appear (with the help of specialist invertebrates) to result in a ‘humus-like’ substance in the heartwood, resulting in a hollow stem without any outside assistance (Read 2000).

Figure A3.2. A brown-rot infected limb from a pedunculate oak Quercus robur (left) and the typical cubical appearance of brown-rot in a pedunculate oak stem (right).

Only 6% of the known wood-rotting fungi are brown rots (Schwarze et al. 2000), and as a group they are much more common in conifers than in broadleaved trees (Lonsdale 1999, Schwarze et al. 2000). In terms of longevity of brown-rot PRF, brown-rot fungi bring about a more rapid drop in the strength properties of the wood than white-rot fungi (Schwarze et al. 2000). None of the brown-rot cavities I have inspected have been occupied by bats, and I could not help but note how dusty and dry they are (to the point of being arid). They also tend to get much larger inside than white-rot cavities. However, the former condition does not appear to put noctules Nyctalus noctula off, and the latter factor may indeed encourage them (see Chapter 4). __________________________________________________________________________________________ A3 - 4

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DEFENCE While trees can react over time to the redundancy of over-shaded branches and to small wounds, they have no active immune system (Rackham 2006). What trees do have however, on a varying scale depending upon the species, is lignin; a brown polymer that coats the white cellulose of which the cells walls of the wood are made (Watson 2006). This ‘lignocellulose’ is very strong and (depending upon the species) contains a combination of oils, resins, gums, tannins and other ‘extractives’ which have varying levels of toxicity to wood-rot fungi (Spooner & Roberts 2005). In some cases the extractives are so strong as to render the species more or less immune to infection (cedars Cedrus spp. are resistant to decay due to the toxins their wood produces (Spooner & Roberts 2005)). This situation is however rare, and the vast majority of trees are susceptible to fungal infection by specialist basidiomycete wood-rotting fungi, which produce digestive enzymes which can break down the lignocellulose and (sometimes) lignin that give heart-wood its structural strength (Spooner & Roberts 2005). The development of PRF is therefore reliant upon a degree of failure within the trees defence mechanisms, allowing the infection to spread but (if the PRF is to last long enough for bats to colonise it) not to entirely overwhelm the tree. Those of you in coastal areas should look out for Monterey cypress Cupressus macrocarpa, an ornamental species favoured for its resistance to salt spray. Despite its resistance to decay, the species is always worth close inspection as it produces excellent fissure PRF as a product of its growth form, where the stem segues into the limbs and the limbs into the branches. For the fungal hyphae to progress through the wood it must penetrate the ‘walls’ of the woods cells. These walls were divided and categorised by Shigo & Marx (1977) and Shigo (1979) within the Compartmentalisation of Decay In Trees (CODIT) model as: Wall 1 – the weakest wall: prevents the spread of decay above and below; Wall 2 – the second weakest wall: prevents the spread of decay into inner rings previously untouched by damage; Wall 3 – the strongest wall at the time damage occurred: prevents the spread of decay round the rays in which the damage has occurred; and Wall 4 – the repair wall: prevents the decay from infected wood, into new wood (growth rings) that will subsequently be formed.

COMPARTMENTALISATION OF DECAY IN TREES (CODIT) In order to understand how decay PRF form, it’s necessary to understand what CODIT is and how it works. I have provided the following text with the caveat that it simplifies trees and CODIT in a way that I can understand, and therefore to an absurd level. Let us imagine we’re going to make a mature tree and to make it we’re going to build it from disc-like sections of lots of different sizes. First we must make our discs and, in order to make something approximating the real thing, we’ll need building blocks which (as we all know) are called ‘cells’, to cement together in order to make the trees ‘tissue’.

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Cells In very simple terms, we need three sorts of cells: Parenchyma cells – to extend the tree upward and expand the tree in diameter within the cambium, and for the transfer of water vapour and gasses;  Xylem cells – to hold the whole thing up and also act as the plumbing, taking water and minerals up the tree; and  Phloem cells - to take sugar and starch energy from the leaves down the tree to feed the stem and roots and fuel growth and the creation of leaves etc. Parenchyma cells All tree tissue initially comprises soft and pliable cells known as ‘parenchyma’ cells. Soft cells aren’t however very good for support and protection, so in order to make our tree we’re going to need to adapt some of these parenchyma cells to make some of them more rigid (in order to support the stem and branches), and others to be tough to keep out diseases. Xylem cells To make the xylem cells were going to take some parenchyma cells and ‘lignify’ them; line them with a wax called ‘lignin’ to strengthen them. Then we need to remove the top and bottom walls, and make the side walls semi-permeable by perforating them with lots of tiny holes known as ‘pits’. Later, we’ll glue them together end on end to form open pipes. Phloem cells To make the phloem tissue, we’re again going to take some parenchyma cells, but this time we’ll leave the top and bottom walls on, and coat them on the outside with two waxes; cutin for protection and suberin as an a fungicide and for waterproofing (Schwarze et al. 2000). Middle lamella Now we’re going to take the three sorts of cells and make a single thickness disc, and to hold the cells together we’re going to glue them with a mixture of pectin and lignin; an ultraadhesive that both binds the cells into tissue but also divides them, and is known as the ‘middle lamella’ (Schwarze et al. 2000).

Core So let’s begin making a disc. We don't want the cells in a random pattern; in fact what we’re aiming for is something visually similar to a bicycle-wheel. We’ll start by making a 'core' of xylem cells to represent the wheel-hub (see Figure A3.3).

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Figure A3.3. Left: Idealised representation of a tree section showing the xylem core with the cells held together by the middle lamella (shown in red). Right: Photo of a pedunculate oak Quercus robur section showing the xylem core.

Medullary rays Now we'll add the spoke-like medullary rays, and for these we’ll use live parenchyma cells in alternating light and dark shades to illustrate the two thicknesses; the Primary rays, and the Secondary Rays (see Figure A3.4).

Figure A3.4. Left: Idealised representation of a tree section showing the xylem core and the parenchyma medullary rays. Right: Photo of parenchyma rays in pedunculate oak Quercus robur.

Xylem rings Then we’ll fill in the gaps between the spokes by going round and inserting increasingly large circles of xylem, one on top of the other, also in light and dark shades (see Figure A3.5). This __________________________________________________________________________________________ A3 - 7

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represents the annual growth rings, each with an internal band of light ‘early’ wood, and both denser and darker ‘late’ wood (in fact this variation in shade is brought about by the density of the cells and not any actual difference in colour, but for simplicity I’ve used different colours for illustrative purposes; to highlight the growth-ring effect).

Figure A3.5. Left: Idealised representation of a tree section showing the xylem core, parenchyma medullary rays and xylem tissue. Right: Annual growth rings in Quercus robur.

Cambium Then we can add the live cambium layer to act as the wheel-rim (see Figure A3.6).

Figure A3.6. Left: Idealised representation of a tree section showing the xylem core, parenchyma medullary rays, xylem tissue and parenchyma cambium. Right: Sumach Rhus typhina section showing the cambium green under the paper-thin brown bark. __________________________________________________________________________________________ A3 - 8

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Phloem 'bark' Finally, we’ll add the phloem cells to represent the tyre; now take the slice and hold it up and you’re looking across an idealised (and greatly simplified) representation of a section of tree stem (see Figure A3.7).

Figure A3.7. Left: Idealised representation of a tree section showing the xylem core, parenchyma medullary rays, xylem tissue, parenchyma cambium and phloem skin. Right: Sessile oak Quercus patraea stem section showing the xylem core, rays, xylem tissue, and phloem but without discernible cambium as the section is long dead.

Stem Now we know how to make one disc, we can make a big pile of lots of different diameters and stack them up; widest at the bottom and narrowest at the top, to make our idealised tree stem. Figure A3.8 shows a section pulled out slightly so you can see it.

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CODIT LINES OF DEFENCE Wall 1 When a tree is infected by a fungus, its first line of defence is CODIT Wall 1. This wall is the cell membrane that divides cells from their neighbours above and below (see Figure A3.9). As every cell has its own cell walls, and these are separated from each other by the glue of the middle lamella, there are successions of Wall 1’s all the way up the tree. However, the xylem cells are open above and below to match up with the cells above to form the pipework of the tree’s plumbing. Wall 1 is therefore the weakest wall in the trees defence, as the fungal hyphae can pass straight up and down the tree via these pipes, thus entirely bypassing the toxic extractives (although as will be described later, some trees have a defence mechanism in this event).

Figure A3.9. Illustration of the CODIT Wall 1 plane of influence.

Wall 2 Referring to the full section shown in Figure 5, and regardless of the cells used, the slice is made up of rings of cells squashed around a central core, in alternating light and dark concentric-circles as you’d get if you cut an onion in half transversely. If you pair up a light circle with a dark, each pair represent the growth rings you count to tell a tree’s age when it was felled. The back cell walls face the core, and the front cell walls facing out are CODIT Wall 2 (see Figure A3.10). As with Wall 1, there are successions of Wall 2’s (the front and back face of the cell), one after the other into the centre of the stem. However, Wall 2 is weakened by the numerous pits (holes) in the cell walls in the xylem, and also in the parenchyma of the medullary rays. Wall 2 is therefore only marginally stronger than Wall 1.

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Figure A3.10. Illustration of the CODIT Wall 2 plane of influence.

Wall 3 Now let’s turn our attention to just the parenchyma cells in the medullary rays, which radiate from the core of the stem to the bark, exactly as the membranes of an orange look when you cut one in half transversely. These rays are made from live parenchyma cells stacked at different levels, and truncated so they don’t form a continuous strip of tissue over the full diameter of the trunk (Watson 2006). This arrangement strengthens the stem, holding the annual rings together, and acts as a line of defence against any infection spreading over the total diameter of the stem (Lonsdale 1999, Watson 2006). The rays are CODIT Wall 3’s (see Figure A3.11). Rays come in two thicknesses; the Primary rays, and the Secondary Rays. It might be logical to assume that a thicker wall would be a more effective defence than a thinner wall. However, the rays in heartwood actually promote the greatest spread for many wood-rotting fungi (Boddy & Rayner 1983), and the rays of ash Fraxinus excelsior and beech Fagus sylvatica may be preferentially attacked (Schwarze & Fink 1998). Reference to Schwarze et al. (2000) suggests that in many cases the rays appear to act as the wood-rot super-highway!

Figure A3.11. Illustration of the CODIT Wall 3 plane of influence.

Wall 4 So we have walls 1, 2 and 3 illustrated, but what of wall 4? Well this is where the phloem and cambium come in to play. Simplifying the true situation to suit our purposes; the phloem cells (the tyre on the bicycle-wheel of our artificial and idealised tree section) combine to form the bark, which armours the outside of the tree. Just under the phloem, is another layer of parenchyma, this is the cambium (the wheel-rim on the bicycle-wheel of our artificial and idealised tree section). Where the bark is tough and corky on the outside, the cambium is soft and slimy. That slime is the ‘meristem’; the growing tissue where the cells divide to form __________________________________________________________________________________________ A3 - 11

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new parenchyma cells and thus enlarge the tree over the spring and summer. These new cells will be either retained as parenchyma lengthening the medullary rays, or adapted to form xylem or phloem depending on which side of the cambium they form (xylem inside, phloem outside). Regardless of their ultimate purpose, all the cells form in two shades, those formed in spring being of a noticeably lighter shade than those formed later in the year. The combined phloem/cambium layer is Wall 4 (see Figure A3.12) and Wall 4 is formed after wounding (Watson 2006).

Figure A3.12. Illustration of the CODIT Wall 4 plane of influence.

Unlike Walls 1, 2 and 3 Wall 4 is the only active defensive wall (all the others are passive; essentially dead wood that acts as the trees plumbing etc.). Only Wall 4 has the power to initiate damage-control and repair, by growing across a wound to seal it in. When a tree is damaged so seriously that the bark is breached, and the wound penetrates the wood inside, Wall 4 is breached. Although trees cannot heal in the way animals can, they can over time cover up damaged tissue with a skin of ‘woundwood’ callus (also see Chapter 5), the purpose of which is specifically to plug or seal tree wounds when damage occurs (Watson 2006). So when damage is sustained the live cambium of Wall 4 begins to form woundwood at the wound edges in order to slowly grow over the damage, closing the gap in order to keep pathogens (such as wood-rotting fungi) out. This process takes time however, often several years for the gap to fully close, and the tree may therefore be infected by any number of pathogens in the interim. Even if the tree manages to close the gap with Wall 4 in successive years, in many cases all it has done is sealed in the infection and the decay often continues to do its damage, working up the stem past Wall 1 (eating away the successively narrower column of infected heartwood) and down the stem (eating away the successively wider diameter heartwood), past Wall 2 and into the centre (although very rarely across the core (Watson 2006)), and around the rays of Wall 3. In most cases a very tall ‘slice of cake’ wedge will be formed, but in some cases an entirely hollow spire may be the result.

HOW CODIT WORKS If you imagine the bark is the trees battlement, if it’s penetrated decay fungi can enter and attack the heartwood inside (see Figure A3.13). Ordinarily, this doesn’t kill the tree straight away and, if given time, the bark will gradually grow out and may even grow over the gap altogether. However, the growth is very slow and only occurs in the spring and summer period. If damage occurs in the autumn winter period, then the fungi have at least six months to get inside and infect the wound. __________________________________________________________________________________________ A3 - 12

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Once infection has occurred, the speed the infection spreads depends on the fungus and the host tree; different species of tree have different compartmentalisation ability; birch Betula spp., poplar Populus spp. and willow Salix spp. are weak, whereas oak Quercus spp., lime Tilia spp. and (perhaps surprisingly) beech Fagus spp. are strong compartmentalisers (Schwarze et al. 2000). Ultimately, all the tree’s defences do is slow the progress of the fungi, they rarely stop it completely and they can't kill the infection, so sooner or later the rot will spread.

Figure A3.13. Wall 4 is breached and decay enters, only to be slowed by Walls 2 & 3. We already know that Wall 1’s are the weakest walls, and Wall 2 and 3’s aren’t much better. So even if the tree manages to close the gap with Wall 4, the decay may continue to do its damage, working up the stem (eating away the successively narrower column of infected heartwood) and down the stem (eating away the successively wider diameter heartwood), into the centre and all the way around the rays (see Figure A3.14).

Figure A3.14. Decay has penetrated Wall 4 at some point in the distant past. From here it has breached Wall 1, and is heading into and around Walls 2 and 3. However, Wall 4 has held, put on new growth and is now trying to close the gap, hence the elliptical hole.

If Wall 4 closes the entrance, then the bats are waiting for a kindly woodpecker to open one up (see Figure A3.15: left). If not, then you get a rot-hole (see Figure A3.15: right) which, hopefully, extends up into a nice tall, darkened, dry, spire (see Photos A3.1 & A3.2) and heypresto – a fantastic PRF. __________________________________________________________________________________________ A3 - 13

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Figure A3.15. Left: Wall 1 has failed, but Walls 2 and 3 have slowed the rot but may yet be overcome, and Wall 4 has sealed the gap (top of picture). Right: Walls 1, 2 and 5 have failed and 4 haven’t sealed the gap. Both are ash Fraxinus excelsior stems.

Photo A3.1. A crack willow Salix fragilis limb that had split. You can see the back of a great-spotted woodpecker Dendrocopus major hole on the left, but look to the right; you can clearly see the Wall 4 going up in a 50 cm high spire, the rotten wood yellowish against the white of the healthy wood. Had this remained and the soft-wood degenerated, this would have been a beautiful PRF.

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Photo A3.2. The limb in Photo 3, seen end-on. You can clearly see Wall 4 as a black line with the rot-softened wood in the centre of the limb and the sound wood under the bark, with all its successive Wall 4’s.

However, nothing is ever simple, and while the greater percentage of decay results in a voidtype PRF, perennial cankers (‘perennial’ because the fruiting ‘conk’ is present and readily visible year-round) use Wall 4 as a bridge by which to overcome Wall 1 resulting in the formation of longitudinal crevice-type PRF. Cankers, having first invaded the wood by an artificial entry point such as a frost-crack, impact wound, branch-drop etc., invade the bark from the inside, and by using the bark to bridge the compartmentalisation wall, can then bypass the compartmentalisation walls to attack the healthy wood beyond and, when once again blocked by a wall, revert back to the bark and again bridge the defence (Lonsdale 1999). Such infections are most effective at bypassing Wall 1 and as a result tend to result in a longitudinal wedge in the stem. All this does however rely on the premise that the fungi has infected via damage above ground, but this isn’t the only way in; many fungi colonise from below via the roots. Böttcher & Liese (1975) showed that roots near the stem form heartwood which passes directly into the stem from below. This means that it has hardly any defence mechanism against woodrotting fungi that attack from the roots (Schwarze et al. 2000). However, as with the situation where Wall 4 has sealed a stem wound, where infection penetrates via the roots; the core may be hollow (particularly if there is also a stem rot working down from above) but inaccessible to bats unless another animal, or storm-damage, creates an opening. __________________________________________________________________________________________ A3 - 15

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Lonsdale (1999) highlights the fact that although decay fungi do cause physiological and mechanical damage, in most cases the fungi develop slowly and tend to exploit the central cylinder of the tree, and infected trees often survive in a partly decayed state for many years, even centuries.

WHY DECAY & DEFENCE MATTERS TO BATS In Chapter A2 we touched upon how the inherent growth form of trees influences the internal shape of PRF, but the formation of many PRF is dependent upon fungal infection to bring about the hollowing needed to provide a sheltered and dark environment in which bats can roost. It can, I hope, be accepted that the presence of decay fungi is one of the most significant factors separating good bat roost woodlands from bad bat roost woodlands. However, in 2012 this sweeping statement is more or less all that can be said, because which fungi are most associated with PRF formation is still unknown. It would appear reasonable to suggest that the white-rot fungi upon which woodpeckers appear to depend will be important for that very reason to Bechstein's bats Myotis bechsteinii, Daubenton's bats M. daubentonii and noctules Nyctalus noctula. But what of the fungi that turn knot-holes into wide cylinders and blank tear-outs into tall spires? Different fungi behave in different ways. Some fungi produce an excess of moisture leaving the internal conditions both wet and mucky, but this doesn't necessarily put bats off; I have seen a Natterer's bat Myotis nattereri in a damp and mucky tear-out, and a brown long-eared bat Plecotus auritus in a wet-walled butt-rot. Other fungi, such as the brown-rot beefsteak fungus Fistulina hepatica leave the internal conditions arid and dusty but Cindy Blamey (Woodkeeper of Highgate Wood, north London) has found woodpecker-holes in beefsteak fungus infected oaks occupied by noctules in autumn for mating, and an oak infected by chicken-of-the-woods Laetiporus sulphurous (also a brown-rot) occupied by noctules and then Natterer’s bats. In our email interchange, Cindy related to me that when woodpeckerholes infected with beefsteak fungus are occupied by noctules, the powdery orange dust is sometimes knocked out and conspicuous under the hole, with droppings mixed in. There is evidence to support a link between pelage and concealment. Barrett-Hamilton (1910) suggests that “although to a great extent [bats are] creatures of the night, their external coloration is evidently subject to laws similar to those which govern that of diurnal mammals”. So does the colour of bats fur act as camouflage? This thought first occurred to me in relation to brown long-eared bats Plecotus auritus and grey long-eared bats Plecotus austriacus. I wondered why the grey was grey, and whether it had a connection with its typical resting place. The distribution of grey long-eared bats appears to have a coastal bias, and I wondered if greys were grey because natural selection favours grey fur for bats that roost in sea-caves (assuming they do roost in sea caves of course), and browns were brown because they roosted in trees. Then I got to thinking about the Myotids Myotis spp. and whether they are dark on top and light underneath like a Spitfire is camouflage on top (so it’s hard to see from above) and sky blue underneath (so it’s hard to see from below). Lord knows why barbastelles Barbastella barbastellus are black (roosts in coal-mines?), but it would be interesting to see whether the ginger fur of noctules has any significant correlation with a preference for roosts in brown-rot infected stems.

It appears to me, that the identification of the fungi species most associated with decay PRF formation in each tree species will bring about the next leap forward in our ability to identify roosts and target effort to the woodlands and trees with highest roost potential. It would __________________________________________________________________________________________ A3 - 16

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certainly be interesting to find out whether specific fungi species, in specific tree species, are associated with specific bat species.

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TREES – DECAY PRF GENERAL The Decay Class includes all PRF in which the greater agent in the formation of the feature is a wood-rotting fungus. In 2012 the known Decay PRF comprise:  Woodpecker-holes;  Knot-holes;  Flush-cuts;  Tear-outs;  Double-leaders;  Wounds & Cankers; and  Butt rots. Of these overall seven PRF types, Woodpecker-holes, Wounds & Cankers and Butt-rots only occur when the tree is infected by a wood-rotting fungus. The other four; Knot-holes, Flushcuts, Tear-outs and Double-leaders, all occur without fungal infection, but only develop into PRF if fungal infection occurs and eats the wood.

Photo A4.1. Highgate Woodkeeper Cindy Blamey inspects a noctule Nyctalus noctula roost in a great spotted woodpecker Dendrocopus major hole on an ash Fraxinus excelsior. Note the fungal fruit-body (bracket) behind the branch stub on the stem above the hole. © Cindy Blamey 2013. __________________________________________________________________________________________ A4 - 1

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WOODPECKER-HOLES General Woodpecker-holes are associated with pre-existing hollow stems (typically the result of a brown-rot; see previous chapter) or limbs, or stems and limbs infected by white-rot fungi such as Phellinus igniarius, Phellinus robustus and Inonotus hispidus, which soften the wood (Weber & Mattheck 2003) without weakening it to such an extent that failure is immediate.

Formation Whilst they occupy old holes in which to night-roost (Gorman 2004), our native woodpeckers generally excavate a new nest-hole each year (Cramp 1985, Gibbons et al. 1993, Stenberg 1996). In suitable sites, the woodpecker excavates ‘into’ the limb and then down, with little taken from above the entrance tunnel (Cramp et al. 1985) (See Photo A4.2).

Photo A4.2. Crack willow Salix fragilis stem section holding a typical woodpecker-hole. This green woodpecker Picus viridis hole did not hold a bat-roost. __________________________________________________________________________________________ A4 - 2

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As a general rule, holes occupied for nesting (egg-laying/rearing young and night-roosting) tend to be either individual or aligned on a vertical axis (H. Andrews pers. obs.). In contrast, typically discontinuous holes bored in the course of digging out invertebrate prey may be grouped or arranged horizontally (see Figure A4.1).

Figure A4.1. Left: Three woodpecker-holes arranged vertically, all leading into a hollow stem. Right: Three woodpecker-holes arranged horizontally and all discontinuous. N.B. none of these hold bat-roosts.

Table A4.1, on the following page, provides a summary of the preferences exhibited by the three woodpecker species native to the British Isles in relation to nest sites and nest-hole characteristics. Overall, broadleaved trees appear to be favoured but some conifers are also used, although the presence of sticky resin in pines Pinus spp., Douglas fir Pseudotsuga menziesii, larch Larix spp. and spruce Picea spp. (Thomas 2000) can be predicted to restrict woodpecker presence to entirely dead stems or limbs. I find it interesting that whilst yew Taxus baccata does not contain resin, and hemlocks Tsuga spp, true cedars Cedrus spp, and firs Abies spp. have the resin restricted more or less to the bark (Thomas 2000), they rarely hold even prospective woodpecker-holes (author Pers obs.). I can only hypothesise that this may be as a result of their having far less in the way of associated pathogens in the form or wood-rotting fungi, which would otherwise soften the wood to a more favourable composition for excavation.

Identification The only PRF that could potentially be confused with a Woodpecker hole is a Knot-hole, but in contrast to knot holes, woodpecker-holes do not have a pronounced ‘collar’ around the entrance.

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Table A4.1. A summary of the preferences exhibited by the three woodpecker’s native to the British Isles in relation to nest sites and nest-hole characteristics. SPECIES

Green woodpecker Picus viridis Although open broadleaved woodland used (Cramp et al. 1985), favours wooded country rather than woodland (Campbell 1953), parkland, orchard, gardens, heathland (with trees) and hedgerows (Cramp et al. 1985). Oaks Quercus spp., birch (Cady & Hume 1988), ash Fraxinus spp. (Gibbons et al. 1993), elm Ulmus spp., apple Malus spp., alder and both chestnuts Castanea sativa and Aesculus hippocastanum (Campbell 1953) used Less reliant on decaying wood (Hagvar et al. 1990, Gorman 2004), favours trees that are sound externally, but with rotten core (Campbell 1953) Up to 15 m (Cady & Hume 1988), favoured heights cited vary between 1-10 m (Cramp et al. 1985, Gibbons et al. 1993, Stenberg 1996, Gorman 2004) Typically on the stem (Campbell 1953, Gorman 2004), but sometimes on large sloping boughs (Campbell 1953)

Great spotted woodpecker Dendrocopos major Woodland parkland and, gardens (Cramp et al. 1985, Gibbons et al. 1993). Will occupy conifer plantations where dead trees exist, and also use adventitious birches Betula spp. (Campbell 1953)

Lesser spotted woodpecker Dendrocopos minor Riparian alder and willow carr and extensive broadleaved woodland (Sharrock 1976, Gibbons et al. 1993). Parks, orchards & gardens (Cady & Hume 1988)

Birch, oaks, ash, alder, elm, sycamore (Campbell 1953, Cady & Hume 1988, Smith 1997). Birch and pine Pinus spp. popular in the north (Campbell 1953)

Presence of easily-worked decaying wood seems to be more important than tree species (Cramp et al. 1985)

Excavation limited to dead and rotting trees (Cramp et al. 1985)

Dead trees (Gorman 2004). Cavities made in decaying wood (Gibbons et al. 1993)

0.4-20 m (Cramp 1985). Favoured heights cited vary; 3-5 m (Cramp et al. 1985), 5-10 m (Stenberg 1996)

ENTRANCE DIAMETER INTERNAL DEPTH INTERNAL DIAMETER INTERNAL SHAPE

6-7 cm (Gorman 2004)

COMMENTS

Often found in upper areas of valleys than spotted woodpeckers Dendrocopus spp. (Gibbons et al. 1993). Selects trees with clear, open flight-paths (Gorman 2004)

5-6 cm, often slightly elliptical (Cramp et al. 1985) 25-35 cm (Cramp et al. 1985) 11-12 cm (Cramp et al. 1985) Entrance tunnel level to core but nest chamber typically a vertical-sided cylinder rather than the gourd-shape of green woodpecker (author Pers obs.) Nest-holes have a pointed lower rim, whilst roost-holes are round (Cramp et al. 1985). May bore in 10 cm to get wood-boring beetles and larvae. (Cramp et al. 1985)

1-25 m (Cady & Hume 1988), exceptionally < 1 m (Cramp et al. 1985). Favoured heights cited vary; 2-5 m (Stenberg 1996), 2-8 m (Cramp et al. 1985) Branches favoured (Gorman 2004), often on underside of dead limbs (Campbell 1953, Cramp et al. 1985). May also nest in stem of small trees (Campbell 1953) 3-3.5 cm (Cady & Hume 1988, Cramp et al. 1985) 10-18 cm (Cramp et al. 1985) 10-12 cm (Cramp et al. 1985) No data.

HABITAT

TREE SPECIES

TREE CONDITION

HOLE HEIGHT

HOLE LOCATION

30-50(60) cm (Campbell 1953, Cramp et al. 1985) 15-18 cm (Cramp et al. 1985) Entrance tunnel straight to the heartwood core, turning downward and widening into the nesting chamber (Thomson et al. 1923)

Hole typically on the stem (Cady & Hume 1988, Smith 1997, Gorman 2004)

Conifers and dense, mature woodlands are avoided (Cramp et al. 1985)

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Bat occupancy Table A4.2 sets out the bat species known in 2012, from detailed accounts and photographic evidence, to make use of Woodpecker-holes as roost sites. Table A4.2. The bat species known from detailed accounts and photographic evidence to make use of Woodpecker-holes as roost sites. BAT SPECIES Bechstein’s bat Myotis bechsteinii Daubenton’s bat Myotis daubentonii Leisler's bat Nyctalus leisleri Noctule Nyctalus noctula

ROOST STATUS Maternity (Vesey-Fitzgerald 1949, Flanders & Hill 2004, Forestry Commission for England & Wales et al. 2005, Harris & Yalden 2008, Dietz & Pir 2011) Maternity (Boonman 2000, Nagel & Haussler 2003, Dietz & Boye 2004, Forestry Commission for England & Wales et al. 2005) Maternity (Ruczyński & Bogdanowicz 2005) Maternity & Transition including mating (Stratmann 1978, Heise 1985, Kronwitter 1988, Frank 1997, Boonman 2000, Kanuch 2005, Ruczyński & Bogdanowicz 2005)

Unfortunately, published accounts of Woodpecker-hole roosts do not describe the position the bats were roosting in, and I have myself only found and looked inside three Woodpeckerhole roosts while the bats were present. These comprise two Daubenton’s bat Myotis daubentonii maternity roosts and one noctule Nyctalus noctula lekking roost (all in greatspotted woodpecker Dendrocopus major holes). All had significant upward development with a dome-shaped apex. The Daubenton’s colonies were roosting in the woodpecker-hole apex. The individual noctule was, however, roosting below the apex dome, but above the entrance, on the side wall opposite the entrance hole (see Figure A4.2).

Figure A4.2. Left: Noctule Nyctalus noctula ‘lekking’ roost in a mature pedunculate oak Quercus robur. Right: The noctule coming down to greet me. __________________________________________________________________________________________ A4 - 5

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In their superb account of Bechstein's bats Myotis bechsteinii in Luxembourg, Dietz & Pir (2011) gave the internal measurements of five Woodpecker-holes used by Bechstein’s maternity colonies and all had upward development ranging from 31 cm to 60 cm above the entrance hole. In contrast, (while they did not provide an account of the position the Bechstein’s bats in their study were roosting) Hohti et al. (2011) did record at least one maternity colony of Bechstein’s bats in Slovakia roosting in a typical Woodpecker-hole with no internal height. Ruczyński & Bogdanowicz (2005) recorded a mean internal height of 9.54 cm in the noctule maternity roosts they recorded, but this was within a range of 0.0-80.0 cm, confirming that maternity colonies of the species regularly occupy Woodpecker-holes with little or no upward decay column.

Photo A4.3. Woodpecker-hole in crack-willow Salix fragilis used by a Daubenton’s bat Myotis daubentonii maternity colony numbering 22 bats. Note the tiny hole below the entrance which held a wasp’s nest.

Overall, woodpecker-holes are associated more with white-rots than brown-rots. But is the upward development of woodpecker holes more often associated with brown-rots which entirely break-down the wood thereby creating a hollow column, or white-rots which leave the wood more or less intact but softer and lighter? If so, are woodpecker-holes in brown-rot infected trees more likely to be occupied by the Bechstein’s Myotis bechsteinii, Daubenton’s M.daubentonii and noctules Nyctalus noctula that favour Woodpecker-holes, than the same feature in a white-rot, or do different species have specific preferences i.e. noctules in brown-rots and Bechstein’s and Daubenton’s in white-rots?

Cindy Blamey (Woodkeeper: Highgate Wood) has related an instance of an individual noctule she discovered which was roosting below the entrance on the internal wall of a woodpecker-hole again with no upward development, so ordinary Woodpecker-holes with no upward development have been used in this country, if only by individuals. __________________________________________________________________________________________ A4 - 6

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This is certainly an aspect of tree-roosting ecology that is desperately in need of more detail and I would welcome more input; is a roost position below the entrance exceptional or perhaps a habit of individual subordinate male noctules in the mating season? Or is it far more widespread?

KNOT-HOLES General As the upper canopy of the tree develops, or the woodland canopy closes and shades out limbs below, energy is redirected into the upper canopy as the surrounding trees (and even individual limbs on the same tree) compete for light (Thomas 2000). Knot-holes are artefacts of gradual redundancy from shading, or sudden death via damage which kills the branch without tearing it from the stem (Mattheck & Breloer 2010). Reference to the literature review in Chapter 10 will reward the reader with many references to bat-roosts within knot-holes, but none were accompanied by photographs or descriptive accounts and, for my part, I have never encountered a knot-hole roost that was not either a misidentified woodpecker-hole or flush-cut, and could not therefore be attributed to the same processes; symbiosis between bird or chainsaw and fungus. I was therefore becoming increasingly concerned that I was missing something, but last year Matt Dodds told me about Dietz & Pir (2011) which includes three clear photographs of Bechstein’s maternity roosts in Knot-holes, and this year I got some information from John Haddow with supporting photographs taken by Stuart Spray, both of the Scottish Leisler’s Project. Now read on…

Figure A4.3. Left: Knot-hole on ash Fraxinus excelsior at 6 m height holding at least six Leisler’s bats. © Stuart Spray 2012. Right: Stuart Spray demonstrates the size of the entrance (7 cm) and (scary bit) although it goes in 17 cm and has a depth of 10 cm, it does not go up at all! © Stuart Spray 2013 __________________________________________________________________________________________ A4 - 7

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Formation The moment a branch dies, for whatever reason, its vascular tissue within the stem stops developing (Mattheck & Breloer 2010). As the stem-wood continues to develop around the base of the dead branch, a distinct ‘branch-collar’ may form at the point where it circles the redundant branch base. Such collar formation represents a weak point at which the branch may subsequently be lost in its entirety (Mattheck & Breloer 2010), but in many cases (particularly in oak Quercus spp.) the redundant branch will gradually decay and drop in small sections, until only the collar remains. A fallen branch initially leaves a stump (as shown in Figure A4.4) but as the junction between the branch and stem consists of woven fibres which run along the branch and turn downward into the stem, the dead branch-heel rots away downward into the stem, leaving a hole. It is important to keep in mind that the tail or ‘heel’ of branch fibres run into the stem and turn downwards; never upwards. The stem tissue above the branch is therefore the stems’ alone (Mattheck & Breloer 1994). So when a branch dies the all the dead wood is associated with the branch not the stem; the dead wood in the stem is branch-wood and comprises only a downward pointed spike of xylem tissue. This is why Knotholes on the stem only ever extend downward unless the tree is in the advanced stages of decay either from a localised infection or from a major infection that has penetrated the stem core from the roots, leaving the stem hollow. In the latter case the Knot-hole has simply linked with an entirely independent hollow. However, in isolation, Knot-holes pose the least possible risk of decay extending into the stem (Mattheck & Breloer 1994).

Figure A4.4. An existing Knot hole (below) and a Knot hole in formation (above).

As a result, despite their overall abundance, of all the rot-hollows Knot-holes appear in __________________________________________________________________________________________ A4 - 8

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general the least likely wound to develop into a PRF; the loss of the branch being a gradual process, with compartmentalisation of the branch ‘heel’ within the host limb or stem and the strong formation of protection wood preventing infection. In particular, where a branch dies back due to gradual redundancy, the trees natural defence boundary between live and dead wood often forms at or near the base and typically does not even extend down into the parent stem (Lonsdale 1999). There is strong evidence to suggest that this is not universally applicable to all tree species as it assumes all trees are composed of the same wood, and have the same high degree of durability and/or compartmentalisation in the face of infection, which isn’t actually the case. As we will discuss later in Chapter 9, ‘woods’ like ‘bats’ aren’t all the same thing, and (in my experience) while oak, elm Ulmus spp. and sweet chestnut Castanea sativa generally do not form Knot-holes that do not enlarge inward or upward until the tree attains great age. In my investigations over the course of this summer, I have found Knot-holes on large ash Fraxinus excelsior trees growing in damp conditions which connect with high and wide rot-columns, and a disproportionate number of youngish (± 30 cm dbh) alder Alnus spp. holding one or more Knot-holes that opened into an entirely hollow stem. Furthermore, Knot-holes don’t just form on stems, they also form on branches. Knot-holes that form on the elbow of a branch that is bowed downward (such as those often encountered on ash and horse chestnut Aesculus hippocastanum) will have the branch heel extending upward into the older limb from which they emerge, and these may (very often in the case of horse chestnut) develop into a tall, thin spire, entirely open from below but nonetheless dark and sheltered (I have yet to find a bat roosting in one, but I have found several that appear eminently suitable (see Photo A4.4) and of course any evidence would be lost in the leaf-litter on the woodland floor below).

Photo A4.4. Horse chestnut Aesculus hippocastanum downward orientated Knot-hole.

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This is certainly a PRF that needs far greater scrutiny with perhaps a focussed investigation in damp habitats such as Carr woodland.

Identification When separating Knot-holes from Woodpecker-holes and other rot-hollows, the rule of thumb is that if it’s circular and has a complete collar (see Photo A4.5) it’s a Knot-hole; if it isn’t and it doesn’t then it’s something else. In practice the only PRF a knot-hole might be mistaken for are Flush-cuts and Tear-outs. In the case of Flush-cuts (N.B. the misidentification of Knot-holes, Tear-outs and Flush-cuts makes no difference in the key at present), until the branch tail has entirely rotted away, they are conspicuous by the flat surface of the cut; obviously the work of a saw and not a natural processes. In the case of branch-tears the shape is the immediate give-away; knot-holes are always round, whilst Tear-outs are always ‘key-hole’ or upside down ‘tear-drop’ shaped, as in order to qualify, the branch ‘heel’ has to have torn out of the host stem or limb, thus leaving a conspicuous tail.

Photo A4.5. Knot-hole collar in formation. An extreme example I grant you, but it illustrates the feature.

Bat occupancy Table A4.3 on the following page sets out the bat species known in 2012, from detailed accounts and photographic evidence, to make use of Knot-holes as roost sites. __________________________________________________________________________________________ A4 - 10

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Table A4.3. The bat species known from detailed accounts and photographic evidence to make use of Knot-holes as roost sites. BAT SPECIES Bechstein's bat Myotis bechsteinii Leisler’s bat Nyctalus leisleri

ROOST STATUS Maternity (Dietz & Pir 2011) Maternity & Transition (J. Haddow 2012 pers. comm., March)

As with noctules in woodpecker-holes, Leisler’s bats Nyctalus leisleri will occupy Knot-holes even where they have no upward development. This was also true of the Leisler’s bats in Ruczyński & Bogdanowicz (2005) study where although the mean internal height was 21.89 cm, the range of internal heights in which maternity colonies were found was 0.0-130.0 cm. Again we come back to internal characteristics, but don’t let’s be seduced by the behaviour of a single species into blindly accepting that this is applicable for all species; further clarification is needed; do you know of a Knot-hole roost? Can you add anything to the discussion?

Figure A4.5. Left: Leisler’s bat Nyctalus leisleri roost in a knot-hole at 8.2 m height on a beech Fagus sylvatica in Culzean Country Park (National Trust for Scotland). © Stuart Spray 2012. Right: Close-up of the knot-hole, which opens up into a 265 cm high rotcolumn that held nine Leisler’s bats. © Stuart Spray 2012.

FLUSH-CUTS General Flush-cuts are superficially very similar to Knot-holes, and may be misidentified as such. They have however one very important difference; Flush-cuts are not a natural process __________________________________________________________________________________________ A4 - 11

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controlled by the tree and occurring over a long-period, but a sudden injury to the tree caused by the removal of a limb with a saw.

Formation Where a chainsaw cut is flush to the stem the tree’s protection boundary is entirely removed and the trees natural defences are ineffective (Lonsdale 1999, Shigo 1986). In addition, such a cut also leads to a loss of vitality in the tissue around the wound (Shigo 1986), thereby retarding effective occlusion formation and facilitating the ingress of pathogens such as white-rot fungi. So, in contrast to the formation of a Knot-hole, which results in a downward orientated tongue within the stem (but not into the stem tissue), in a Flush-cut wound the zone of decay may extend not only downward on the seam of branch tissue but also laterally and vertically (Lonsdale 1999). Furthermore, if several Flush-cuts occur sequentially up the stem, it is likely that the decay will not be confined to an individual cone, but combine to form one elongated column (Lonsdale 1999). Even where a collar of callous does form, due to the failure of the tree to form sufficient occlusion wood quickly (as a result in the reduction of energy reserves in the remaining tissue), narrow crevices may open round the sides of dead, desiccated and contracted heart-wood (see Photo A4.6).

Photo A4.6. Flush-cut on oak Quercus robur. Note the crevices between heartwood and occlusion wood, particularly at the top. This tree is adjacent to a public road.

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Identification The characteristic flat-surface of a Flush-cut is conspicuous and, as Flush-cuts are an artefact of a perceived risk to life or property by overhanging tree-limbs, they are a rare feature in woodland; restricted to rides, footpaths, picnic areas and pylon-line wayleaves.

Bat occupancy I have been unable to find accounts describing flush-cut roosts, but know that they are used by Leisler’s bats from a photograph (credited to Stuart Spray) in an article in the IEEM’s In Practice magazine (Catherine & Amphlett 2011). Table A4.4 lists the only bat species proven to use flush-cuts as roost sites, but is this the only one? Table A4.4. The bat species known from detailed accounts and photographic evidence to make use of flush-cuts as roost sites. BAT SPECIES Leisler’s bat Nyctalus leisleri

ROOST STATUS Transition (Catherine & Amphlett 2011)

TEAR-OUTS General While Tear-outs can form anywhere on the stem, they are more often found well below the canopy, where branches are more or less at right angles from the stem and over-reaching in order that twigs still hold viable foliage. Note: In the first edition of this text I had originally misnamed Tear-outs as ‘Branch-drops’ but, as the revised text illustrates, Branch-drops have an entirely different origin. In light of further investigation into the formation and accepted arboricultural nomenclature, I have adopted the more widely-used name given to the feature by the experts.

Formation Although high winds can tear branches from trees, Tear-outs are more typically the result of snow-damage, where the weight of a cushion of snow resting within twigs on such an overstretched branch has caused it to tear from the stem (Lonsdale 1999, Thomas 2000). When this happens, the branch ‘heel’ rips through the stem tissue taking a long strip with it and leaving a large open scar with a characteristic ‘key-hole’ shape when they’re recent, but becoming more like an upside-down tear-drop as the woundwood heals the edges (see Photo A4.7 on the following page). The natural death of redundant branches, and a snap that removes the branch but leaves the collar intact, does not damage the CODIT Walls within the host stem or limb, and over time the tree can seal the wound with callus growth. A Tear-out however goes deep into the central column of the tree; penetrating its natural defences and breaching Wall 4 at a single __________________________________________________________________________________________ A4 - 13

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stroke, thereby allowing fungal spores to enter. In addition, due to the extensive damage which exposes large areas of old and young tissue, woundwood rarely fully occludes the wound (Watson 2006). Bacteria and fungi therefore have a good probability of successfully colonising the tree and progressing downward into the branch heel but, more importantly, upward into the stem core, creating a hollow cone.

Photo A4.7. An artificially created Tear-out on a rowan Sorbus aucuparia sapling in my garden provided in order to illustrate the origin and shape of the feature.

While evergreen trees appear to suffer from snow tear-outs more than deciduous trees (James 1982), Tear-outs also appear to be more common to some species with Lonsdale (1999) citing blue Atlas cedar Cedrus atlantica var. glauca and horse chestnut as particularly susceptible (whether they develop into PRF in these species is, however, quite another matter). Lonsdale (2000) also highlights lapsed broadleaved pollards as also being of highrisk for tear-out wounds, which would be a site for potential decay in the main stem below. In addition, even in calm conditions, large branches may be shed due to summer branch-drop which may be as a result of fungal infection causing a brittle fracture at the point of infection, or be the result of changes in the amount of water in the trees stem (Lonsdale 1999). The latter circumstance causes a sudden change in pressure within the trees plumbing, not just increases, but also decreases causing shrinkage. Lonsdale (1999) cites shrinkage as a potential cause of summer branch-drop. Whatever the cause, the site of breakage is always a branch junction, which is the weakest point (op. cit.). Such basal failure where the branch is __________________________________________________________________________________________ A4 - 14

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torn out of the host limb or stem will leave a deep wound and, as with a Flush-cut, such a sudden occurrence will leave the tree with no time to compartmentalise the affected area and defend itself against the ingress of fungal infection. Extensive decay is therefore significantly more probable in such wound than in a knot-hole. Lonsdale (1999) highlights beech Fagus sylvatica, horse chestnut and elms as being particularly susceptible, and interestingly Rackham (2003) again highlights summer branchdrops as a feature of large elms (not that they’re often encountered these days), suggesting that the phenomenon may be due to a build-up of methane caused by bacterial wet-rot in the stem, which forces limbs off on calm and hot summer days (Rackham 2003). Tear-outs occur at heights typically ranging from 2 m right up into the canopy. Whilst I have found more suitable and occupied Tear-out PRF on sycamores Acer pseudoplatanus than any other tree (and would recommend looking for them wherever there are sycamores near water; male Daubenton’s in particular seem to like them), I’ve also found Tear-out roosts on ash (Daubenton’s and brown long-eared bats Plecotus auritus) and been shown tear-outs occupied by barbastelle Barbastella barbastellus in sessile oak Quercus patraea by Dr. Geoff Billington (see Photo A4.8), a Natterer's bat Myotis nattereri in a field maple Acer Campestre by Carrie White (see Figure A4.8), and an unknown bat in an alder by Daniel Hargreaves.

Photo A4.8. Tear-out in a sessile oak Quercus petraea that holds a barbastelle Barbastella barbastellus maternity-colony (thanks to Dr Geoff Billington).

In conifers the only Tear-out PRF I have thought suitable were in the high-canopy of mature Corsican pines Pinus nigra (above 0.5 m DBH), although I did also once find a Scots pine Pinus sylvestris that had dropped a branch at 3 m on a woodland-edge so they must crop up in parks. As a general rule the brashing and thinning of plantations results in a lack of branches other than in the high-canopy (and I wish you luck, and at least three throw-bags if you’re going to attempt to get into the canopy in a pine plantation).

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Photo A4.9. A sycamore Acer pseudoplatanus Tear-out that had held two Daubenton’s bats Myotis daubentonii males. Note the smooth surface, typical of inhabited cavities.

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Figure A4.6. Sycamore Acer pseudoplatanus Tear-outs holding low numbers of Daubenton’s bats Myotis daubentonii. Tear-outs might be mistaken for knot-holes, but the latter is round, and the former is ‘keyhole’ shaped as the branch ‘heel’ has torn out of the host stem or limb.

Bat occupancy Table A4.5. The bat species known from detailed accounts and photographic evidence to make use of Tear-outs as roost sites. BAT SPECIES Barbastelle Barbastella barbastellus Bechstein’s bat Myotis bechsteinii Daubenton’s bat Myotis daubentonii Natterer's bat Myotis nattereri Leisler’s bat Nyctalus leisleri Common pipistrelle Pipistrellus pipistrellus Soprano pipistrelle Pipistrellus pygmaeus

ROOST STATUS Maternity (Billington 2004, Natural England 2012) Maternity & Transition (Dietz & Pir 2011) Maternity & Transition Transition (H. Andrews, pers. obs.) Maternity & Transition (J. Haddow 2012 pers. comm., March) Transition (D. Dowse 2012, pers. comm., January) Transition (D. Dowse 2012, pers. comm., January)

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Where rot-processes have penetrated the trees efforts at compartmentalisation and extended up into the stem tear-outs make excellent bat-roost cavities. The lack of any bowl section in the base precludes any significant build-up of droppings and I have found such roosts to be occupied continuously over periods of weeks rather than days (although I cannot be sure it was by the same bat).

Figure A4.7. Natterer’s bat Myotis nattereri roost in a tear-out on a field maple Acer campestre holding an individual bat. This roost was discovered in November 2012 by Carrie White while out walking her dog (Celeste). What’s interesting is that the base is really sludgy with all sorts of clutter in the base (including empty snail shells) and the point in which the bat was roosting was also damp. __________________________________________________________________________________________ A4 - 18

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DOUBLE-LEADERS General Bat roosts in double-leaders where first brought to widespread attention of bat workers by Dr Garry Mortimer as a result of his PhD study into the ecology of Natterer’s bats in plantation woodland. I am indebted to Dr Mortimer for agreeing to provide descriptions, advice and guidance in the production of the following text, and to Anne Youngman of Bat Conservation Trust for bringing Dr Mortimer’s work to my attention.

Formation The ‘leader’ on a tree is the primary growth limb, typically central to the crown, and longer (taller) than all the other lateral limbs; think of your Christmas tree; the leader is the limb upon which you perch the fairy. Double-leaders are two stems of equal diameter that emerge from the same point on the trunk/limb, ascending in parallel to form the main upward growth, with neither one outgrowing the other (Lonsdale 2000, Shigo 1986, Watson 2006). Double-leaders are also known as ‘co-dominant stems’ and some may become ‘compression-forks’. When looking for detailed information regarding double-leaders in tree books it is wise to search the index for all three labels.

Photo A4.10. A double-leader in a Corsican pine Pinus nigra in a thinned plantation woodland; no bats but it does illustrate what to look for. __________________________________________________________________________________________ A4 - 19

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Double-leaders occur on many broadleaved trees as a natural development in the crown. Lonsdale (2000) suggests willow Salix spp., poplar Populus spp, horse chestnut, beech, ash and true cedars are the species upon which they are typical. Daniel Hargreaves has a superb piece of footage of a maternity colony of Natterer's bats exiting a Double-leader on a beech at http://www.youtube.com/watch?v=ElmnxWAOJjg&sns=em My principal interest in double-leaders comes from the fact that they readily form in conifers such as (but not exclusive to) Corsican pine, Scots pine, Douglas fir and larch species; making plantation woodlands suddenly much more interesting (scary even).

Photo A4.11. Looking up at a double-leader on a Corsican pine Pinus nigra at Westonbirt arboretum; now if they haven’t managed them out, where else hasn’t’!?!

In coniferous trees, which tend to have a conical development with the stem-leader clearly dominant to lateral limbs; double-leaders are the result of damage to, or loss of, the terminal bud in the early stages of development (Baldwin 1993). This may be for a number of reasons but typically it is the due to the unwelcome attentions of squirrels, and where there is one damaged tree, there are often several in a group. Photograph A4.12 on the following page shows a double leader in a Japanese Thuja Thuja standishii that is in a small group in the corner of otherwise semi-natural woodland, all the Thuja are double-leaders yet none of the adjacent broadleaves are.

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Photograph A4.12. Double-leader on Japanese Thuja Thuja standishii. The fork is cracked (entrances on either side but not in the crotch) and the decay column goes c. 80 cm down into the stem. No bats have yet been found in this tree. Note the tree behind it to the right is a double-leader, as is the tree just showing on the left.

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Whilst some species are able to recover and return to a single leader, this is not universally the case (Perks et al. 2005) and some trees that develop double-leaders relatively near the ground when the tree is young, may retain them into maturity. Ideally (from the trees perspective) the annual thickening will ultimately fuse and the two stems will be surrounded by a single annual ring like a sheath, increasing up the two stems with each subsequent year’s growth (Mattheck & Breloer 1994). Whilst fused crotches such as these may develop a sunken cup-like shape from which the overflow of rain-water may be observed, this is not necessarily an indication of decay (Lonsdale 1999, Andrews pers obs.). However, my investigations over the course of this year suggest that while the fusing described above is not uncommon in beech, it is rarer (if it occurs at all) in conifers. So how do double-leaders provide a PRF? Well, when double-leaders form but do not fuse at the fork, the annual thickening acts as a wedge pushing the two limbs apart and such doubleleaders are known as ‘compression-forks’ (Mattheck & Breloer 1994, Watson 2006). There are situations where the growth increments of the two leaders forces the union apart to such an extent that the stem below the fork splits. This may also happen due to the weight of snow in the canopy during winter, or in strong winds. Obviously when this happens a limb may just split away and collapse. An example of this is shown in Frank Greenaway’s 2001 article The Barbastelle in Britain (British Wildlife Vol. 12, No. 5), where the photograph in the top right corner of Page 333 is a barbastelle roost in a failed double-leader on a beech tree (although if the roost is in a failed double-leader it is arguably a branch-tear). However, where the split is not significant, the tree will gradually cover the gap with each annual growth increase. Even where the stem below the fork has not split, double-leaders with acute crotch-angles often have a region of bark-to-bark contact, evident by bark which is double-ribbed and gives the appearance of lips (Lonsdale 2000). These ‘lips’, where the bark between the two stems appears to fold inwards into the fork, indicate included bark. Double-leaders with included bark do not form connective tissue between the stems (Matheny & Clark 1994), but instead the bark of each stem meets against that of its neighbour as a cushioned edge, leaving a narrow fissure between the stems where the two leaders move independently. Where the two leaders can move independently self-wounding is common, as the stems rub against each-other inside the woundwood sheath. Where this happens, there will typically be a pronounced thickening of the stem below the crotch as the incremental growth-rings of the two leaders push against each other and flare out on either side. This flaring growth can become so pronounced as to appear like large ears, and they are actually known amongst woodsmen and tree-surgeons as ‘elephant’s-ears’ (see Photo A4.13 on the following page). Lonsdale (1999) cites this ‘bark-to-bark’ contact as the most common inherent ‘aboveground’ (rather than roots) weakness in trees and cites horse chestnut as particularly prone³. Data arising from the 1987 gales showed double-leaders accounted for 20% of above-ground failures; 52% of which were in beech with incidence of failures in horse chestnut also high (Lonsdale 1999). If little or no fusion has occurred, a ridge (like two parted lips) appears from between the two limbs down onto the stem (Lonsdale 1999). In some cases the lips may gape apart on either side (or only one) on the elephant’s-ears beneath the crotch. Photo A4.14 on the following page shows a Double-leader with included bark. __________________________________________________________________________________________ A4 - 22

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Photo A4.13. A Double-leader on a beech Fagus sylvatica illustrating where the ‘elephant’s-ears’ tag comes from.

Photo A4.14. Double-leader on a pedunculate oak Quercus robur with included bark. __________________________________________________________________________________________ A4 - 23

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Section A. TREES Chapter A4 – Trees – Decay PRF __________________________________________________________________________________________ One of the most frustrating and infuriating aspects of this project has, for me, been the vast amount of inconclusive accounts of potential tree-roosting by common pipistrelles Pipistrellus pipistrellus in horse chestnuts Aesculus hippocastanum cited in consultancy ultrasound survey reports. Time after time the survey teams are evidently confident that the bat emerged from somewhere in the tree, and sometimes the discussion within the report is entertaining as the writer turns the situation over trying to make some sense of it; there is no PRF visible, yet the bat definitely emerged from the limb, or did it..? I wonder if Double-leaders are the answer; small diameter Double-leader PRF on horse chestnut might be numerous, but well camouflaged, and any bat emerging would simply appear suddenly at dusk, and vanish into the clutter of the limbs upon return! The probability of actually witnessing the emergence from over a metre away would be infinitesimal. The feature is not dissimilar to the shape of pipistrelle roosts I have encountered in cavity walls and, where the entrance hole is located between the two leaders, entry would be gained in the same way; up, over, and then down.

As the tree increases in diameter each year by putting on another layer of wood under the bark, the self-wounded fissure gradually grows in depth between the two. In addition, as the parallel stems increase in diameter, the bark surrounding the individual stem on one side is pushing against the bark of the adjacent stem, resulting in the crack in the trunk below widening over time (see Photo A4.15 on the following page). In addition, as rain runs down the stems, a small amount of water gathers in the fork collecting between the included lips. Where a gap is present and water can enter the fissure below this provides favourable conditions for rot-fungi to colonise and where this happens the rot attacks the heartwood, at first creating a narrow column of rot (See Photo A4.16 on Page 26) but slowly breaking it down and leaving a wide cylindrical cavity with a small entrance between the limbs (See Photos A4.17 & A4.18 on Pages 26 & 27 respectively). Dr Mortimer found that suitable roost sites formed in Corsican pine and western hemlock Tsuga heterophylla. Over the course of 2012 I have also found suitable features in Douglas fir (but all had in fact been selectively felled and were on the woodland floor in sections (don’t worry, none had developed far enough to hold a roost) and Japanese Thuja. Whilst double-leaders may form on any tree, Dr Mortimer observed that the forks on Scot’s pine double-leaders often form at a wide angle, and may not therefore form the necessary included bark. Despite the incipient weakness, where double-leaders have developed within a Corsican pine plantation, they are shielded from the effects of wind and encouraged to grow straight upwards due to crowding, such fissures may be very deep. Whilst the entrance hole may be between the fork, or below on one side (on the seam of the elephants-ears), the entrance holes tend to be far smaller on close-grouped conifers than on broadleaves in more open seminatural woods due to crowding. This shields the effects of wind-throw on the stems (which would push the stems away from each other), and snow-hang on branches (that has the effect of pulling the stems away from each other), thereby rending open a greater entrance hole. As double-leading is a deformity which results in a lower timber yield from the individual tree (Perks et al. 2005), they are often weeded out during thinning (at least in well-managed compartments). However, (as we will see later in Chapter A7) not all plantations are selectively thinned but may be thinned in ranks. As a result, double-leader trees sometimes survive into maturity. Readers in possession of Forestry Commission Booklet No.15: Know your Conifers (Edlin 1976), should turn to Page 17 where they will find that just to the left of __________________________________________________________________________________________ A4 - 24

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the truck in Plate 4 there is a Corsican pine with a superb double-leader, the included lips clearly visible and extending well down onto the main stem-below; I wonder…

Photo A4.15. Double-leader on Corsican pine Pinus nigra. It can be seen that this crack is extending as the tree grows and the weight above increases, by following the barklips, which far extend downwards on the tree. This tree held a maternity colony of Natterer’s bats Myotis nattereri. © G. Mortimer 2013. __________________________________________________________________________________________ A4 - 25

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Photo A4.16. Double leader in a young Douglas fir Pseudotsuga menziesii; note the small entrance of darkened wood at the top of the split, highlighted by the light sapwood on either side, leading down into a rot-column in the single stem below.

Photo A4.17. Looking down into a double-leader rot column on a Scots pine Pinus sylvestris from above. The entrance to this one is very open and the base holds a bird’s nest. Dr Mortimer concluded that such open double-leaders were a feature of Scots pine and were not used by bats, whereas the same feature on a Corsican pine P. nigra typically has a much smaller entrance which would be used by bats. This photograph is simply to illustrate the rot column which would be almost impossible with a Corsican pine (unless I cut it down and sectioned it).

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Photo A4.18. The internal cylinder of a heart-rotted Corsican pine Pinus nigra stem below a double leader. The base of the tree is at the bottom of the photograph, the double leaders are at the top and it can be clearly seen the bark edges on both sections are occlusion cushions that would simply have been pressed together rather than fused down the long split. © G. Mortimer 2013.

Identification Double-leaders are so distinctive they are unlikely to be mistaken for anything else. However, when searching for potential roosts, the key characteristic to look for would appear to be the shape of the bark in the crotch between the two stems. Where the junction is ˄-shaped (peaked) with bark in the crotch raised into a pronounced ridge, the union is strong (Shigo 1986) and is therefore unlikely to hold a split or rot-column. If the junction is V-shaped however, and the bark is turned inward (‘included’), the union is weak (Shigo 1986) and the stem below may well be worth a closer look. The key characteristics to look for are:  The shape the crotch:- a V-union and not a ˄-union;  Included bark lips (particularly where the lips extend a good way down the stem below the fork);  A pronounced crack on the line of the lips, which is open on the seam;  A damp patch where liquid is escaping at the base of the seam below the fork; and __________________________________________________________________________________________ A4 - 27

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 A swelling of the trunk (known as ‘elephants-ears’) on either side below the fork.

Bat occupancy In Dr Mortimer’s study the bats gained access to the roost via the small opening at the top, between the leaders, where the bark did not quite reach round and close the gap. Some of the roosts were of significant depth, with Natterer’s bats roosting as much as 2.5 m down from the roost entrance. However, the trees were not of significant age with roosts recorded in specimens of approximately 30 years. Table A4.6. The bat species known from detailed accounts and photographic evidence to make use of Double-leaders as roost sites. BAT SPECIES Natterer’s bat Myotis nattereri Brown long-eared bat Plecotus auritus

ROOST STATUS Maternity (Mortimer 2005, D. Hargreaves 2012, pers. comm., November) Transition (K. Zealand 2012, pers. comm., October)

Where the entrance is sufficiently small, Dr Mortimer considered the roosts excellent for a wide variety of reasons including:  Predator avoidance:  The roosts are difficult to see;  The droppings are all in the base, and therefore no evidence of occupation is visible from outside; and  The microclimate is stable within.

WOUNDS & CANKERS General The bark of some species of trees is particularly prone to damage due to its soft and thin nature (if only when the tree is young). Ash, beech and sycamore all stand out as susceptible and these same species are also prone to cankers.

Formation Wounds may occur for a variety of reasons including basal impact from vehicles, limb and stem impact from the fall of an adjacent tree, penetration damage from nails etc. and, in the spring, grey squirrels Sciurus carolinensis and red squirrels Sciurus vulgaris stripping bark to get at the sweet sap underneath (Lonsdale 1999, Thomas 2000). The sap of young sycamores appears particularly attractive to grey squirrels, but they also attack beech, ash, oak, birch, sweet chestnut and maple (Shorten 1954). Squirrel damage is particularly noticeable in sycamore and beech (Lonsdale 1999, Thomas 2000), whereas red squirrels appear to concentrate on Scots pine, but also attack larch and spruce (ibid.). Grey squirrel damage tends __________________________________________________________________________________________ A4 - 28

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to be on the stem on smaller trees, but move on to smaller limbs when the tree is of c. 40 years or more (Kerr & Evans 1993). Cankers are changes in the texture of wood resulting from the death of the cambium where no new bark is formed (Spooner & Roberts 2005). Certain fungi can repeatedly kill new callus tissue that forms around their point of entry inducing a perennial canker (Lonsdale 1999), so called because the fruiting ‘conk’ is present and readily visible year-round. Having first invaded the wood by an artificial entry point such as a frost-crack, impact wound, branch-drop etc., Cankers invade the bark from the inside, and by using the bark to bridge the compartmentalisation wall, can then bypass the compartmentalisation walls to attack the healthy wood beyond and, when once again blocked by a wall, revert back to the bark and again bridge the defence (Lonsdale 1999). In plantations, ash canker (caused by Nectria galligena) may distort the stem and create sunken cavities (Kerr & Evans 1993). Such infections are most effective at bypassing Wall 1 and as a result tend to result in a longitudinal wedge in the stem (see Photo A4.20 later in this document).

Identification Wounds and cankers are recognisable by the rough edges and indistinct shape of the entrance, around which bark may appear ruffled and pitted (see Photo A4.19). The entrance may be longitudinally elongated (see Photo’s A4.20 & A4.21) or more or less diamond shaped (see Photo A4.22). Such rot-holes can occur anywhere on young trees, but on more mature specimens are more often restricted to younger, thinner, bark on canopy limbs.

Photo A4.19. Ruffled and pitted cankered bark on a young ash Fraxinus excelsior. __________________________________________________________________________________________ A4 - 29

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Photo A4.20. Canker in ash Fraxinus excelsior. N.B. this did not hold roosting bats on the day of survey.

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Figure A4.8. Noctule Nyctalus noctula roost in a cankered ash Fraxinus excelsior. Don't be too focussed on the streak running down from the entrance; it's a symptom of the canker and not bat urine, unless that is (see bottom right) the bats are weeing upwards as they leave… © Antony Croft 2013.

Bat occupancy Table A4.7 on the following page lists the bat species known from detailed accounts and photographic evidence to make use of Wounds & Cankers as roost sites. __________________________________________________________________________________________ A4 - 31

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Table A4.7. The bat species known from detailed accounts and photographic evidence to make use of Wounds & Cankers as roost sites. BAT SPECIES Daubenton's bat Myotis daubentonii Leisler’s bat Nyctalus leisleri Noctule Nyctalus noctula Brown long-eared bat Plecotus auritus

ROOST STATUS Transition (H. Andrews pers. obs.) Maternity & Transition (J. Haddow 2012, pers. comm., March) Maternity (A. Croft 2012, pers. comm., November) Transition (H. Andrews pers. obs.)

Wounds & Cankers typically have an internal bowl-section in which droppings may accumulate. In addition, the ruffled nature of the bark also serves to trap droppings.

Photo A4.21. Wounds & Cankers on beech Fagus sylvatica at 17 m, the one central to the photograph held an individual brown long-eared bat Plecotus auritus. The bat was in the apex c. 30 cm up from the entrance which is at the top of the photograph. The roost was in fact a tube, as the canker continued c. 90 cm up from the entrance point.

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Photo A4.22. The diamond-shaped hole of a pitted sycamore Acer pseudoplatanus canker PRF, this one holding two Daubenton’s bats Myotis daubentonii.

BUTT-ROTS General Butt-rot, as the name suggests, causes decay at the base of the tree typically opening into the heartwood between buttress-roots.

Formation Many butt-rots appear to enter the tree via the root system (Lonsdale 1999) and there may therefore be no sign of damage above ground. Whatever the origin, where the rot is near the surface as the cambium reacts to the soft decay and the increased bending of the stem, it puts on unusually wide annual rings which produce a bulge at the base of the stem (Schwarze et al. 2000). Where the butt splits (perhaps during high winds) the result is typically an archshaped entrance into the stem and extending up into the heartwood in a moderately large diameter hollow dome. Where the annual rings are excessively large this results in a phenomenon known as 'bottlebutt' where the butt of the tree assumes a gourd-shaped appearance, with the stem extending __________________________________________________________________________________________ A4 - 33

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up rather like the constricted neck of a bottle (see Photo A4.23).

Identification Butt-rots may be mistaken for frost-cracks and vice-versa. In fact in the first edition of this text, I mistook a Frost-crack for a Butt-rot, but there is one key difference; Butt-rots do not have the bark-seam extending up the stem from the apex of the entrance arch (where the stem has split and then closed again). Frost-cracks always have this characteristic seam (see Chapter A6: Damage PRF). In addition, butt-rot often leaves the tree with the flared bottlebutt, and sometimes with characteristic folds of tissue producing a wave-like effect in the bark (see Photo A4.23).

Photo A4.23. Bottle-butt on a pedunculate oak Quercus robur.

Bat occupancy I am particularly interested in any accounts of bats occupying such voids as I have several in areas of pristine bat habitat in Somerset. One of these Butt-rots always appears suspiciously clean but, despite intermittent checks over two years; I have yet to find a bat or any conclusive evidence of occupation in it. However, Butt-rots don't just occur on broadleaved trees and, if anything, may be more common on conifers. __________________________________________________________________________________________ A4 - 34

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Figure A4.9 below shows a mature Douglas fir with a brown-rot which had extended up from the roosts, and held a soprano pipistrelle Pipistrellus pygmaeus hibernation roost with approximately 40 bats discovered when it was felled (R. Koczy 2012, pers. comm., November).

Figure A4.9. A Douglas fir Pseudotsuga menziesii Butt-rot holding a soprano pipistrelle Pipistrellus pygmaeus hibernation roost (photo © R. Koczy 2013). The hand on the right is pointing to a bat, still in its hibernation fissure, forearm and body clearly visible.

Table A4.8 lists the bat species known from detailed accounts and photographic evidence to make use of Butt-rots as roost sites. Table A4.8. The bat species known from detailed accounts and photographic evidence to make use of Wounds & Cankers as roost sites. BAT SPECIES Soprano pipistrelle Pipistrellus pygmaeus

ROOST STATUS Hibernation (R. Koczy 2012, pers. comm., November)

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TREES – DAMAGE & REPAIR DAMAGE As we now know some damage, even when superficial in physical terms, acts to let in fungi which go on to create PRF as a by-product of the infection. Other damage is however the sole agent of PRF formation and no further development is needed; indeed in some instances infection by fungi may render the feature unsuitable for bats. In addition, the growth the tree puts on in response to damage may itself create a sheltered feature in which bats can roost. For me, these are the really interesting PRF, as when they occur, they may occur in legions and on a good day you can walk from roost, to roost, to roost, each one superficially the same but each one holding a different species of bat. I’m speaking of the Damage PRF, and they are the group about which the least amount is known, perhaps because they tend to be occupied by individual males and not the maternity colonies which are the ‘conservation priority’ upon which meagre research resources are (quite rightly) expended, but also probably because they are less straightforward to identify and have therefore historically been lumped together by naturalists as ‘cracks’ and ‘crevices’. Trees sustain damage in a myriad ways such as; car impact, tree/limb impact, sudden changes in temperature, root compaction, the knives of love-struck teenagers (although now much less common now than when I was a lad), the flush-cuts of well-intentioned tree surgery, the weight of snow and ice, and the teeth of squirrels, deer, cows (yes cows) and several beetle species. However, in the vast majority of cases, everything in this list needs decay to bring about PRF formation. The damage that brings about the formation of a PRF with no assistance other than the trees own response typically comprises:  Wind;  Compression; and  Frost.

Wind Have you ever stopped to think just how much pressure the stem of a tree has to bear from the weight of its own crown? Resisting this pressure takes all the tree’s strength, so in strong winds the tree is soon in trouble. Wind is the greatest external destructor of trees, as it causes both bending and shearing (twisting) stresses (Mattheck & Breloer 1994). This is because the crown acts like a sail in the wind, the branches being pushed by gusts and bending away, but the stem below being twisted (Mattheck & Breloer 1994). Mattheck & Breloer (1994) describe the shearing effect of stem tissue being twisted by comparing it to bending or rolling a book; the pages sliding relative to each other with those. __________________________________________________________________________________________ A5 - 1

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If my interpretation is correct, the shearing stress would appear to heave greatest potential for effect within the rays. Such stresses are visually obvious in helical splitting and, I would presume that if these stresses recurred over time they would leave a tree more susceptible to frost cracking. Consistent wind effect can leave trees permanently twisted and this growth acting within the stem can be opened by reversing the force. Again I defer to Mattheck & Breloer (1994) who describe the effect in terms of twisting a section of rope; twisted in the direction of the inherent weave and the section gets shorter, tighter and harder to bend, but reverse the twist and the rope becomes longer, looser and more pliable. In the case of wood tissue, such a dramatic and sudden reversal would be likely to cause a significant split.

Compression Compression may result from subsidence and/or shearing. Subsidence-splits Subsidence-splits occur when curved parts of a stem or limb are bent straight, exactly as the skin of a fresh banana splits if it is bent straight (Mattheck & Breloer 1994). A tree growing on a steep slope will typically grow from a bend at the base; out, and then up. If this bend is bent outwards towards the downhill slope by a subsidence slip, the weight of the stem and crown are then not pushing down onto the butt, but acting as a lever, pushing the tree over. Where the roots are sound and anchored, then the force is all taken up by the bend at the base of the tree, which may subsequently split. Subsidence-splits are ‘radial-splits’ i.e. splitting on the line of the rays. Subsidence-splits tend to occur on heavy branches or leaning stems (Lonsdale 1999). Where trees occur on steep slopes, the splits that form the under-side (on the convex side of the bend) are subsidencesplits (those that form on the upper side are Frost-cracks (yes I know they’re technically ‘splits’ too)). While Frost-cracks may close completely, Subsidence-splits only do so infrequently. Helical-splits Some trees stems have a helical grain, evident in many sweet chestnuts Castanea sativa, hornbeam Carpinus betulus and pollard white Salix alba and crack willows Salix fragilis, where the helical growth form may extend out into the surface bark, but it can also be hidden behind a deceptively ordinary exterior. If such a stem is twisted in the opposite direction (for example by gusts of wind) it has the effect of forcing the grain apart, rather like twisting a rope the wrong way (Mattheck & Breloer 1995). Such damage often results in the outer living tissue of the stem pulling away from the dead heartwood creating crevices which extend horizontally into narrow pockets; these are known as Helical-splits.

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Frost Some species of tree are sensitive to frost damage. This may be due to the sensitivity of the buds, with the frost retarding growth and causing growth-deformities, or it may be due to a predisposition to longitudinal splitting from the base up to 6 m, known as frost-cracking. Frost damage is greatest in damp, deep, narrow valleys (by an uncanny coincidence where our rarest woodland bats are found) which form what are known as ‘frost holes’ (Hanson 1934). In particular woods on north-east, east, south-east and southern aspects are most susceptible, with northern and western aspects significantly less likely to be affected. However, even dells within lowland woods on more-or-less level ground may exhibit localised idiosyncrasies in temperature, being far colder than the woodland around them, and thus act as 'frost-hollows'. The species most liable to frost-cracks are oak Quercus spp., beech Fagus sylvatica, elm Ulmus spp., ash Fraxinus excelsior and sweet chestnut (Hanson 1934). Individual specimens of other broadleaves may also be affected but conifers are not. Frost-cracks close tightly upon re-warming and callus then forms which may occlude the wound even within one growing season. However, the rent is liable again to splitting in far less severe weather, so that the cushions are torn time after time.

REPAIR General To prevent structural failure, trees strengthen weak points in their structure by adding on ‘reaction-wood’. To repair damage, trees put on ‘occlusion-wood’.

Reaction wood Reaction-wood is formed in response to downward pressure and strengthens bends etc. Essentially, as branches bend upward from the stem the tree bolsters the weight that is pushing down on the bend by applying more tissue at that point. Reaction-wood differs from normal wood in its mechanical properties and has the ability to resist downward bending (Lonsdale 1999). In conifers the tree forms reaction-wood on the underside of bent stems and branches to bolster their resistance to the downward pressure, while on broadleaves the reaction-wood forms on the upper side rather like a brace (Desch & Dinwoodie 1996, Lonsdale 1999). So if you were to cut the branch of an oak, you would find the core was closer to the lower surface than the upper (rather like a bicep on a bone), and if you cut a conifer you’d find the core closer to the upper surface. In either case the growth rings appear rather egg-shaped. This situation also applies to bending stems, for example where a tree is growing on a steep slope.

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Occlusion-wood Occlusion-wood or callus is formed in response to damage of live wood. When the bark and cambium are damaged the edges of the wound produce a ‘scab-like’ formation of new wood. Woodsmen know this callus formation as ‘woundwood’. Under favourable conditions this woundwood may grow incrementally across and cover or ‘occlude’ the wound (Stone 1921). As the cambial growth on the stem expends more energy on increasing diameter the woundwood grows across the wound as an elongated ellipse and often seals with a characteristic ‘S’ shape. Woundwood is conspicuous against the rough older bark, by its new young bark which is that of a new twig or young branch (rather like Madonna’s chemicallypeeled head, on the turtle-like hide of her neck). Unfortunately, in the short term, partial occlusion can in fact improve conditions for woodrotting fungi by holding in moisture within the pocket which would otherwise be too dry for fungi to function (Lonsdale 1999). Even where a wound is entirely covered over by woundwood, if infection has occurred the decay may still proceed under the cover of the callus-cap (Stone 1921), although it may be significantly slowed and even stop altogether if the repair is so complete that gas exchange is prevented (Lonsdale 1999, Watson 2006). That doesn’t mean the fungi dies however, and if the wound is opened up again (for example by pollarding following a long interval), the rot may begin again with a vengeance (Watson 2006).

WHY DAMAGE & REPAIR MATTERS TO BATS Occlusion-wood is the vital component in the formation of several PRF including Flush-cuts, Frost-cracks, the ram’s-horns of Lightning strikes, and Double-leaders. ______________________________

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TREES – DAMAGE PRF GENERAL The Damage Class includes all PRF in which the greater agent in the formation of the feature is damage alone. In 2012 the known Damage PRF comprise:  Hazard-beams;  Frost-cracks;  Subsidence, Shearing & Helical-spits;  Lightning-strikes;  Impact-shatters;  Desiccation-fissures;  Transverse-snaps; and  Lifting-bark. Earlier this year I found the following: “vespertilionid bats – statements to the contrary notwithstanding walk well…” and “…no healthy British bat usually finds any difficulty in taking flight from a flat surface” (Barrett-Hamilton 1910). I have taken down five barns, one cottage and taken off the entire roof of a stately home, and under the ridge tiles of all these buildings I found individual soprano pipistrelles Pipistrellus pygmaeus and brown long-eared bats Plecotus auritus nestled horizontally into pocket-like crevices between the bedding mortar and tiles. In addition, I have recorded a brown long-eared bat in hibernation torpor lying horizontally between the top of a door-frame and the lintel above, and another brown long-eared bat that tucked itself into a fold of peeling paint under a ceiling. These are all longitudinal features, but all are orientated horizontally. I would urge that longitudinal PRF that are orientated horizontally are very carefully assessed. It is certain that barbastelle Barbastella barbastellus occupy near horizontal Hazard-beams in very low limbs (< 2 m in which to hibernate (G. Biullington 2011, pers. comm. September) and it’s perfectly possible that other species do also.

HAZARD-BEAMS General Hazard-beams are longitudinal splits in lateral limbs and (less frequently) upright stems, that pass through the entire width, allowing light to be seen through the gap. Hazard-beams can occur at any height, but typically in limbs from 2 m right up into the canopy, and on stems above 4 m.

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Formation Hazard-beams form on both limbs and stems (although they appear to be more common to limbs). Photo A6.1 shows a Hazard-beam in a limb that holds a brown long-eared bat Plecotus auritus roost, and Figure A6.1 on Page 3 shows a Hazard-beam on a stem with a maternity colony in residence. How Hazard-beams form is best described using a limb as an example. Imagine a mature ash Fraxinus excelsior tree with its large lower limbs exhibiting their typical outward and then sudden upward curve. Try to picture the branch from the side in your mind. Can we all agree that if we measured the branch on the upper surface it would be slightly shorter than if we did it on the lower surface?

Photo A6.1. Hazard-beam in oak Quercus robur holding an individual brown long-eared bat Plecotus auritus.

Let’s imagine it’s a very windy night, and the gusts are creating turbulence which causes gyration; throwing the limbs in circles, not only upward and into the bend, but also downward and against the bend. When the large limb is bent against the bend, and in effect straightened, the limb the tissues are subject to internal transverse stresses (across the limb from the core toward the bark, rather than along it; think of the sort of scissor-jack you use to change a car tyre). The branch bend, or elbow has grown to be strong in its bent position, and it simply cannot straighten as the length of the outer wood, bark and all, on the lower side is longer than the length on the upper. As it cannot simply concertina into itself, the wood inside ‘delaminates’, splitting and forcing the elbow off the other half of the limb into a pronounced __________________________________________________________________________________________ A6 - 2

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bulge so the top surface of the branch ends up straight and the bottom surface ends up like an upside-down hump-back bridge with a large more or less diamond-shaped split in-between.

Figure A6.1. Brown long-eared bat Plecotus auritus maternity colony occupying a Hazard-beam in a sessile oak Quercus petraea stem.

I have only found Hazard-beams on pedunculate Quercus robur and sessile oaks Quercus petraea, and crack-willows Salix fragilis, but Lonsdale (1999) cites Girling (1996, pers. comm.) who suggests they are especially common on horse chestnuts Aesculus __________________________________________________________________________________________ A6 - 3

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hippocastanum, I have however only ever found one; in Blake Gardens in Bridgwater (see Photo A6.2) which an enlightened arborist has taken the weight off to preserve it (interestingly Lonsdale’s own illustrative photograph is of a pedunculate oak). However, Mattheck & Breloer (1994) suggest that they are extremely common and “by no means confined to any particular species [as they had] found them in almost all species of tree that they have examined”. They know a thing or two, so I think we can accept the statement, with the caveat (remembering the description of woundwood in Chapter A5) that hazard-beams do not form on conifer limbs as the upper sinews (and soon after, the whole branch) snap. Green (2010) set out the perfectly sensible suggestion that the volume of wood in the trunk of a forest tree might, by virtue of the competition and therefore race for light, be greater than that in the trunk of an open-grown tree of the same age, even though the open-grown tree would have a greater volume of would overall; in its wider and lower crown.

Figure A6.2. A hazard-beam (upright limb in right of photo on left) on an oak Quercus robur at 7.5 m height which is visited by at least two individual female Leisler’s bats Nyctalus leisleri at Culzean Country Park (National Trust for Scotland). © Stuart Spray 2013.

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Open grown trees would (in theory) therefore be more pre-disposed to Hazard-beams in lateral and vertical limbs, than a forest tree, which would (if only by virtue of the fact that the ration of stem to crown would be weighted in the stems favour) be far more likely to have a Hazard-beam in the stem.

Photo A6.2. Hazard-beam on a horse chestnut Aesculus hippocastanum limb in Blake Gardens, Bridgwater.

Identification In practice it is unlikely that a Hazard-beam would be confused with any other PRF, save perhaps a Tear-out. The rule of thumb is that if the split goes right the way through the branch so you can see daylight (see Figure A6.3), it's a Hazard-beam.

Figure A6.3. Left: Hazard-beam in an oak Quercus robur limb holding two brown longeared bats Plecotus auritus. Right: Looking up into the Hazard-beam shortly after the bats had left. __________________________________________________________________________________________ A6 - 5

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Bat occupancy Table A6.1 lists the bats species known from detailed accounts and photographic evidence to make use of hazard-beams as roost sites. Table A6.1. The bat species known from detailed accounts and photographic evidence to make use of hazard-beams as roost sites. BAT SPECIES Barbastelle Barbastella barbastellus Leisler’s bat Nyctalus leisleri Noctule Nyctalus noctula Brown long-eared bat Plecotus auritus

ROOST STATUS Maternity & Hibernation (Billington 2004, Natural England 2012) Maternity & Transition (J. Haddow 2012 pers. comm., March) Hibernation (G. Billington 2011 pers. comm.,September) Maternity & Transition (H. Andrews, pers. obs.)

In limb Hazard-beams, bats are found in the upper end, typically a little below the apex, and resting on their stomachs with their heads down (see Photo A6.3). In stem Hazard-beams they are found as you would expect to find bats in a pitched roof, in the apex and down, tiered on either side.

Photo A6.3. Endoscope-view of the brown long-eared Plecotus auritus in residence in Photo A6.1 hazard-beam (thanks to John Kaczanow for the redetermination of the I.D.). __________________________________________________________________________________________ A6 - 6

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Hazard-beams occur both in all orientations and heights and are used by bats in different orientations and heights for different purposes. More or less vertical Hazard-beams are occupied by barbastelle Barbastella barbastellus and brown long-eared bat maternity colonies in the summer months (barbastelle: G. Billington 2011, pers. comm., September, brown long-eared bat: H. Andrews pers obs.), and by noctules Nyctalus noctula in the winter (G. Billington 2011, pers. comm., September), and low-level more or less horizontal Hazardbeams are occupied in the autumn by brown long-eared bats as transit sites (H. Andrews pers obs.) and barbastelles in the winter as hibernation sites (G. Billington 2011, pers. comm., September).

Photo A6.4. A Hazard beam in an oak Quercus robur occupied by a barbastelle Barbastella barbastellus maternity colony in summer and hibernating noctules Nyctalus noctula in winter (thanks to Geoff Billington).

FROST-CRACKS General Frost-cracks are longitudinal splits in limbs, or cracks in the stem that typically progress from the base of the butt anything up to c. 6 m height. __________________________________________________________________________________________ A6 - 7

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Formation Frost cracks can be divided into two forms:  Outward to inward (Sapwood/bark) splits; and  Inward to outward (Heartwood) splits (Lonsdale 1999). Stone (1921) suggested that as dense wood shrinks more than lighter wood, the Ripewood species of deciduous trees would be more susceptible nearer the surface and would most often develop outward to inward splits, where the heartwood species with their dense centres would be most susceptible to shrinkage in the core and be more likely to develop inward to outward cracks. Frost-cracks do not affect the health of the tree and therefore long-lived PRF. Outward to inward Outward to inward splits may occur on the stem and lateral limbs, but in general occur in broadleaved species with smooth bark such as beech Fagus sylvatica, sycamore Acer pseudoplatanus, young ash and horse chestnut. As the bark is relatively thin these splits at best tend to result in only shallow envelope pockets which offer little in the way of shelter and are subject to a significantly unstable micro-climate. Photo A6.5 shows an outward to inward crack in a beech limb.

Photo A6.5. Outward to inward split in a beech Fagus sylvatica limb. N.B. It is unknown whether this PRF holds roosting bats.

Inward to outward Inward to outward cracks generally occur in the lower section of the tree stem, rather than in lateral limbs. __________________________________________________________________________________________ A6 - 8

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When the temperature drops below freezing, ice is formed in the wood and the water withdrawn from the cell-walls. The result is a drying of the wood accompanied by contraction. As only the outer layer of the tree is frozen, it is contracted against the inner core and thereby rent apart. I have found most (but not all) frost-cracks on slopes in steep valleys and cannot help but think that uneven development plays some part. Stone (1921) suggests that growth rings are typically circular in transverse section unless disturbed by accidents of growth and cites situation on a slope, or receiving sunlight from one side only as a potential cause of abnormal development on one side only, and it's only logical to suppose that a thinner section would tear more easily than a thicker one. That said however, the Frost-cracks I have seen have been very deep, and appeared to span the core.

Figure A6.4. Natterer's bat Myotis nattereri roost in a frost-crack in a dead sessile oak Quercus patraea stem. __________________________________________________________________________________________ A6 - 9

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Figure A6.5. Right: Frost-crack in a sessile oak Quercus petraea stem. Top Right: progressing up inside the stem, note the smooth surface on the left and the 'crevice-type' nature of the internal shape. Bottom right: individual barbastelle Barbastella barbastellus in the apex. __________________________________________________________________________________________ A6 - 10

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The Heartwood ring-porous species (see Chapter A9) may be more susceptible to frostcracking in late spring than the Ripewood and Sapwood diffuse-porous species (see Chapter A9). This is due to main flow of water movement being confined to the outer portion of sapwood, with the most rapid rates recorded in the large springwood xylem vessels which are precisely timed to form annually (Morris & Perring 1974). If I’m right, this formation would be close to the surface of the stem, and would be pulling high volumes of water up into the stem in the spring. If a late frost occurred, this water (as we all know) would expand as it froze, potentially splitting the tree. Certainly oaks are known to be especially prone to frostcracks (Morris & Perring 1974, H. Andrews pers obs. (see Figures A6.4 & A6.5 on the preceding pages). While the spring thaw may see the crack again close (or at least reduce), facilitating a superficial repair by new wood formed in that year, the old wood within cannot repair itself and the repair may therefore be inadequate to prevent the split reopening in the subsequent winter (Lonsdale 1999). Successive splits and repairs result in the formation of protruding lips of callus along the edges of the split; these are known as frost ribs (Lonsdale 1999). In addition, where fissures form between calloused bark and the heartwood beneath, these are known as 'ram's-horns'. Ram's-horns Ram’s-horns are so called because of the appearance of woundwood in cross-section (see Figure A6.6 on the following page), and are the consequence of the rapid growth of wound wood following a longitudinal split, impact wound or bark-stripping (Lonsdale 1999). The new growth turns over into itself and often, whilst the gap is reduced, it does not close the initial split even when the horns meet (Shigo 2008). In extreme cases the rapid growth pushing inward against the heartwood may even force the two apart in some sections, resulting in a sequence of openings into a secluded pocket inward and upward. Where gaps form they comprise a narrow and sheltered longitudinal crevice, or a system of envelope pockets scattered over the length of the split between the new wood and the dead heartwood. Frost-cracks most often form in open woods, which have been over-thinned after growing in a dense state (Hanson 1934). This situation may not be readily apparent as the Frost-cracks may form in a wood and, as they do not affect the health of the tree, the canopy may have subsequently closed. The vast majority of Frost-cracks I have found have been in old coppice oak stems which, following the last harvest which thinned the site, were left unmanaged as the need for charcoal and tan-bark fell into history. Frost-cracks are a particularly abundant feature of the steep-sided Somerset combes, and typically found on the upper side of the stem of sessile oaks in the 'tension-wood' zone. This has a bearing on finding such PRF; there is no point

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walking along the pretty stream-side path in the base of the ravine, you have to get up onto the lip and walk along the woodland edge looking down to find the Frost-cracks!

Figure A6.6. Ram’s-horns shown in cross-section (left) and longitudinally (right).

I live in Bridgwater in Somerset and my weekend stomping grounds are the woods of Exmoor. In one of these woods I have counted over 100 trees with superb frost-cracks in the bases of relatively small sessile oaks Quercus petraea, thus far 23 of these have been found to hold roosting bats. I mention this in passing following a reference by Stone (1921) to Blackmore’s Lorna Doone, set locally, and in which a character relates that the trees burst with a sound like pistol-shots from the extreme cold. I have never encountered frostcracks in such abundance anywhere else, and wonder whether it is a local phenomenon but if so, why?

Identification Frost-cracks might be mistaken for Butt-rots and/or Lightening-strikes, but Butt-rots do not have the diagnostic seam running up from the apex of the entrance hole that Frost-cracks have, and Frost-cracks don't tend to develop anything even approximating 'bottle-butt', nor do they develop folds in the bark at the base of the stem. The longitudinal cracks of Lighteningstrikes pass from the top of the tree, originating somewhere in the crown, all the way to the ground and don’t have a seam. They almost never even begin to close, and are more wavy in appearance, rather than straight along the grain like a Frost-crack. A similar feature has also been produced historically by the use of a device known as a jimjam that was brought to my attention by Rackham (2006). It would appear that this novel __________________________________________________________________________________________ A6 - 12

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invention came about as part of an experiment into the eradication of lime Tilia spp. stools in former coppice woodland. Essentially, it’s a lever-operated syringe about 1 m long with a 10 cm diameter with a very sharp point, the idea being that you swing this into the tree stem and then inject your herbicide to poison the tree (O. Rackham 2012, pers. comm. August). The result (as anyone who knows anything about tree biology will tell you) is that you put your poison into the heart of the tree, and this passes upward (if it moves at all) but not downward, so you get a stem very much like a frost-crack (H. Andrews pers. obs.), but the cambium remains vital, and the roots are untouched. Professor Rackham showed me lime stools where this was readily apparent, and I have subsequently found sweet chestnut Castanea sativa stools adjacent to a railway in Surrey that appeared to have been subjected to the same treatment; it was no more successful.

Bat occupancy Lonsdale (2000) gives a very handy hint for assessing frost cracks; if the shape of the rib is sharp-nosed the crack has not successfully occluded, but if blunt-nosed then the crack is sound, and now overlain by several intact annual growth rings. Table A6.2. The bat species known from detailed accounts and photographic evidence to make use of Frost-cracks as roost sites. BAT SPECIES Barbastelle Barbastella barbastellus Bechstein's bat Myotis bechsteinii Daubenton's bat Myotis daubentonii Natterer's bat Myotis nattereri Noctule Nyctalus noctula Brown long-eared bat Plecotus auritus

ROOST STATUS Transition (H. Andrews, pers. obs.) Transition (Dietz & Pir 2011) Transition (H. Andrews, pers. obs.) Transition (H. Andrews, pers. obs.) Transition & Hibernation (H. Andrews, pers. obs.) Transition & Hibernation (H. Andrews, pers. obs.)

SUBSIDENCE, SHEARING & HELICAL-SPLITS General Subsidence, Shearing and Helical-splits have two very different origins, but are lumped together here due to their identical orientation upon the stems upon which they occur; typically on the convex side of a bend (unlike Frost-cracks which are either on a straight stem or the concave side of a bent limb). __________________________________________________________________________________________ A6 - 13

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My experience is that Subsidence-splits tend to occur from ground-level up to c. 3 m, where Shearing and Helical-splits can occur at a variety of heights.

Formation Splits in the stem can be caused by shearing stress and/or subsidence when the stem is bent, causing a fracture in the lower stem, which develops upwards on the compression (squashed) side (see Figure A6.7). Where the split remains open, fungi may infect the wound and spread into the heartwood creating a hollow. Alternatively, helical (spiralling) cracks can form along a radial crack where the stem is subject to torsion (twisting) (see Figure A6.7).

Figure A6.7. Left: A shearing split. Right: A helical split.

The stems of some tree species have a helical grain, evident in many sweet chestnuts, hornbeam Carpinus betulus and pollard white Salix alba and crack willows (see Photo A6.6) where the helical growth form may extend out into the surface bark, but it can also be hidden behind a deceptively ordinary exterior. If such a stem is twisted in the opposite direction (for example by gusts of wind) it has the effect of forcing the grain apart, rather like twisting a __________________________________________________________________________________________ A6 - 14

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rope the wrong way (Mattheck & Breloer 1995). Such damage often results in the outer living tissue of the stem pulling away from the dead heartwood creating crevices which extend horizontally into narrow pockets. Identification Trees with Subsidence, Shearing and Helical-splits tend to occur more-or-less in isolation. In contrast, Frost-cracks tend to form in groups, with several trees in a small area or stratified in a line all exhibiting the feature. Subsidence-cracks and Shearing-splits form on the convex side of the bend, and Helical-splits twist round the stem, which again separate them from Frost-cracks (which are typically located on the convex side, and in a straight line up the stem, rather than twisting round it).

Photo A6.6. The twisted stem of a pollard white willow Salix alba with a Helical-split.

Bat occupancy I have never found a bat-roost in a Subsidence, Shearing or Helical-split, nor have I met anyone who had. The search continues…

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LIGHTNING-STRIKES General In addition to Frost-cracks, vertical wounds may also be caused by lightning. Lightningstrikes produce huge fissures from the tip of the leader in the crown all the way down to ground-level and are very often conspicuous in a wood from a great distance.

Formation Damage may take two forms; scarring/cracking, and complete rending of the tree. In the latter case the conspicuous fissure often extends from the tip of the leader to the base of the tree. In extreme cases the tree is killed as a result, but in others a strip of bark and young wood with more or less parallel sides is rent along the entire length. Stone (1921) cites an example where a strip of wood, “twisted like a cork-screw…” was thrown some distance from a struck tree. Having read this description, I found one myself (see Figure A6.8) and recalled another I had seen (the first in woodland, the second in pasture, both oaks).

Figure A6.8. Lightening-strike on a sessile oak Quercus petraea. Smooth-barked trees appear to be less often affected than rough-barked species such as oak and elm Ulmus spp. (James 1982). However, alder Alnus glutinosa, ash, beech, cherry Prunus spp., sweet chestnut, elm, plane Platanus spp., poplar Populus spp., sycamore, spruce Picea __________________________________________________________________________________________ A6 - 16

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spp., Douglas fir Pseudotsuga menziesii, larch Larix spp. and Scot’s pine Pinus sylvestris have all been recorded as lightning casualties (James 1982).

Identification It is possible that a Lightning-strike might be confused with a Canker, as where the lips on either side of the fissure become callused they also become irregular (Stone 1921). But Lightning-strikes tend to occur from a point of origin higher in the crown, and are continuous, whereas Cankers tend to comprise a discontinuous series of longitudinal splits with breaks where the bark remains intact.

Bat occupancy I have never encountered a bat in a Lightning-strike. Table A6.3 lists the individual Continental accounts, both of which relate to Leisler's bat Nyctalus leisleri. Table A6.3. The bat species known from detailed accounts and photographic evidence to make use of Lightning-strikes as roost sites. BAT SPECIES Leisler's bat Nyctalus leisleri

ROOST STATUS Unknown (Beck & Schorcht 2005, Ruczyński & Bogdanowicz 2005)

IMPACT-SHATTERS General Impact-shatters, as the name suggests, are sinuous fractures where a lateral limb has been subjected to a sudden and significant blow, usually from a falling limb or an adjacent tree. They typically occur in the crown.

Formation When a limb is snapped, typically by the impact of an adjacent tree falling, or the collision of a branch falling from above, this violent action often results in a multitude of narrow fissures extending and even twisting up into the remaining limb. Where the limb has a downward inclination (such as on ash), and sometimes also in more or less horizontal limbs, these cracks may extend into darkened pockets and crevices in which individual bats can readily hide. The __________________________________________________________________________________________ A6 - 17

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best features are typically (but not always) within limbs where the snag extends beyond the shattered section and exerts sufficient weight to keep the fissures open and stable. Impact-shatters are a feature of mature coniferous plantation trees, in particular the pines. Photo A6.7 on the following page shows an excellent impact-shatter in a Scots pine and Photo A6.8 shows another in a larch.

Photo A6.7. Looking up into an Impact-shatter on Scots pine Pinus sylvestris from below. The branch is entirely dead, no resin was present, and there are a series of narrow crevices and secluded pockets in which bats might shelter. No bats were present, but it was conspicuously clean in many areas.

Photo A6.8. An Impact-shatter on a larch Larix decidua. __________________________________________________________________________________________ A6 - 18

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Identification Impact-shatters are distinctive and are unlikely to be confused with any other PRF.

Bat occupancy I have yet to encounter bats in an impact-shatter, but I have my eye on a couple for repeat attention. Have you ever recorded a bat roosting in one?

DESSICATION-FISSURES General Desiccation-fissures are deep but narrow radial-cracks, and only occur in dead wood.

Photo A6.9. Desiccation-fissures in a dead pedunculate oak Quercus robur but sadly no bats or evidence found in all five survey visits. __________________________________________________________________________________________ A6 - 19

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Formation When a tree dies the wood beneath the bark gradually desiccates and shrinks and the bark falls away, leaving behind deep radial fissures in the bleached heartwood (see Photo A5.10), these are Desiccation-fissures. Deep fissures only form in the heartwood of dead sweet-chestnut and oak, and also within the Ripewood of pollard crack and white willows.

Photo A6.10. Fissure in a dead oak Quercus robur. N.B. This did not hold bats on the day of survey.

Typically large aggregations of bats only occur when the split extends into a darkened pocket allowing the bats to hang. Photo A6.11 shows a noctule roost located in the stem of a (now dead) Monterey cypress Cupressus macrocarpa (Note: in the first edition of this text I had misidentified this tree as a cedar of Lebanon Cedrus libani). The roost is occupied year round; maternity through to hibernation. The split extends into a darkened void at the top, in the apex of which the bats aggregate just as they would in a woodpecker hole, branch-drop or wound void.

Identification Desiccation-fissures only occur in dead wood, and are very distinctive.

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Photo A6.11. A noctule Nyctalus noctula roost in a fissure in a dead Monterey cypress Cupressus macrocarpa (thanks to George Bemment for showing me this one).

Bat occupancy Table A6.4. The bat species known from detailed accounts and photographic evidence to make use of Desiccation-fissures as roost sites. BAT SPECIES Noctule Nyctalus noctula

ROOST STATUS Maternity & Hibernation (H. Andrews, pers. obs.)

TRANSVERSE-SNAPS General Transverse-snaps, as the name suggests, encompass all situations where a stem or limb has broken but, for whatever reason, not become entirely detached from the butt, stem or limb. __________________________________________________________________________________________ A6 - 21

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Formation Where transverse-cracks are present in the stem, this is almost always the result of massive stress where the stem has failed but somehow not entirely snapped/collapsed (Lonsdale 1999). For example, in dense woodland where the canopy catches within adjacent trees and becomes ‘hung-up’.

Photo A6.12. A Transverse-crack in a beech Fagus sylvatica.

Transverse-cracks in the stem may be formed in leaning trees, which may be a result of localised fungal decay or fibre kinking, cracks form in the bark at the top of the decay cavity or at the buckling zone, on the tension side, accompanied by loose bark. Such cavities may result in the tree snapping at the point of the cavity, unless hung-up (resting against another stronger tree). In hung-up stems decay may also extend the size of the cavity upwards, Photo A6.12 illustrates such a stem in which I have found the feeding remains of wood mice and bird droppings, but not bats.

Identification Most Transverse-cracks are associated with Butt-rots and/or Impact-shatters. I would suggest that if the entire tree is leaning over and would fall if it wasn't somehow hung-up, it should be __________________________________________________________________________________________ A6 - 22

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considered a Transverse-crack. Any confusion is however academic and makes no difference to the way the PRF keys out.

Bat occupancy Except in cases of extensive decay, Transverse-cracks are rare (Lonsdale 1999). All published accounts are frustratingly vague, and therefore inconclusive, and I have yet to personally encounter a bat roosting in such a PRF.

LIFTING-BARK General For loose bark to provide a PRF it must comprise a large enough ‘plate’ to allow access from below or one side, shelter from above, and a clean and dry crevice, typically 20 mm wide from the underside of the bark to the heartwood, 300 mm wide from side to side, and no less than 150 mm from the base to the top (G. Billington 2011, pers comm., September).

Formation Loose bark typically occurs as the result of:  intense and localised stretching;  an impact; and/or  the death of the tree or an individual limb. The formation of loose bark plates by intense local stretching typically occurs on leaning trees, and is most pronounced in thick-barked species, such as oaks. Stretching can occur on the stem or branches where the compressed side holds congested bark which is thick and broken into blocks in a zig-zag pattern whilst the tension side holds loosened bark which is thin and lifting, with bare patches (Mattheck & Breloer 2010). Such formations typically occur near the base. Where an impact (for example by a vehicle) strips bark substantially, the living tissue may be unable to bridge the gap. In some cases, whilst callous lips may adhere to the heartwood, sufficient bark may have been lifted during the impact for a darkened crevice to remain. Assuming the repair is sufficient for the tree to survive, such plates can be long-lived supported by the live bark on either side, but unfortunately often don’t extend upward sufficiently far to provide sufficient shelter to represent a PRF.

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Significant bark plates form on dead trees, and occasionally dead limbs. As the heartwood contracts, the fibrous bark does not contract to the same extent, and pulls away from the stem or limb in large sheets. These plates, and even sheets of bark, may have laterally deep and high crevices between the bark and the dead heartwood. However, any PRF of this nature is unstable and ultimately ephemeral; lost as the dead tree breaks-down or the limb is shed. Bats may roost under loose bark in the apex of a bark plate or may crawl sideways, moving round the stem or limb heartwood and thus out of site in a darkened refuge (G. Billington 2011, pers comm., September). Where a bark-plate extends upwards with open sides it is straightforward to check with an endoscope and occasionally, where the sides are open, with a torch alone. However, where the crevice behind extends laterally, a comprehensive inspection may not be possible without risking damage to the PRF (see Photo A6.13), and should therefore not be attempted unless absolutely essential.

Photo A6.13 . Bark plate on Turkey oak Quercus cerris for which comprehensive inspection was not possible a without risking damage to the PRF and injury to any bats potentially present. Bat occupancy __________________________________________________________________________________________ A6 - 24

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Barbastelle in particular appear to favour bark plates with an area of bare heartwood below where the bark has fallen away, upon which bats will land before crawling up into the sheltered crevice above (G. Billington 2011, pers comm., September). Roost occupancy under lifting bark is not only confined to broadleaved trees; a barbastelle has been recorded in a rot cavity behind the bark of a dead Scots pine in November and it was concluded the feature was an early hibernation roost (Natural England 2012). Table A6.5 lists the bat species known from detailed accounts and photographic evidence to make use of Lifting-bark as roost sites. Table A6.5. The bat species known from detailed accounts and photographic evidence to make use of Lifting-bark as roost sites. BAT SPECIES Barbastelle Barbastella barbastellus Bechstein's bat Myotis bechsteinii Brandt's bat Myotis brandtii Daubenton's bat Myotis daubentonii Leisler's bat Nyctalus leisleri Nathusius pipistrelle Pipistrellus nathusii Common pipistrelle Pipistrellus pipistrellus Brown long-eared bat Plecotus auritus

ROOST STATUS Transition & Hibernation (Billington 2004, Natural England 2012) Transition (Cervený & Bürger 1989) Transition (Strelkov 1983, Dietz et al. 2011) Transition (Cervený & Bürger 1989) Hibernation (Harris & Yalden 2008) Transition (Dietz et al. 2011) Transition (Altringham 1999, Dietz et al. 2011) Transition (Boye & Dietz 2005)

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TREES - DIVISIONS GENERAL “Trees are wildlife, not environment; they are not part of the scenery of the theatre of landscape: they are actors in the play, and they perform different roles” Oliver Rackham 2003 Trees of all species face an on-going siege from the environment and pathogens, but individual tree species exhibit widely differing levels of resistance to damage and to the wood-rotting fungi that target them. The reason for this is that, although all trees develop in the same broad fashion, they actually aren’t all made of the same wood, and the different woods behave in different ways. Some species, such as oak Quercus spp. and sweet chestnut Castanea sativa, have an inbuilt chemical resistance and two different forms of wood (Heartwood and Sapwood) which in themselves act as a defence by confounding the specialist nature of the more primitive decay fungi (as will be discussed later). Other species, such as beech Fagus sylvatica have a far lesser chemical defence and so, while they also have two different forms of wood (Ripewood and Sapwood, they are far more susceptible to large-scale decay than oaks. Finally, we have the weakest species such as sycamore Acer pseudoplatanus and birch Betula spp., which have no effective chemical defence and (until they attain relatively great age) only one sort of wood (Sapwood). These differences mean that an oak is unlikely to form a cavity with a domed apex until it is of at least moderate age, but a beech might do so far earlier, and a sycamore or birch earlier still. In contrast, oaks often form really tall and acute spires with the help of frost alone and often preserves them in an otherwise healthy tree for decades, but in my experience beech do so far less, and birch (in England at least) not at all. So, in Chapter A7 we widen our discussion as, whilst all tree species growing in the British Isles share the same basic growth and development (inasmuch as they all put on a new layer of growth in the summer and remain more or less dormant in the winter), that is where the similarity ends. From here the situation becomes progressively more complex as we begin to separate the individual tree species into smaller and smaller groups. The group each tree species falls into has a bearing on their physical forms, the damage and decay they are most susceptible to, and therefore the Potential Roost Features (PRF) they will typically hold.

DIVISIONS As we saw in Chapter A3, in the simplest terms wood is comprised of very small tubes and cells (Hanson 1934). In broadleaves the tubes are open all the way along and in conifers they are interrupted by perforated plates (Tudge 2006).

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The first stage of dividing the different species, is just that; dividing them into the two ‘divisions’, either broadleaved or coniferous.

Broadleaves Known to foresters as the ‘hardwood’ family (Desch & Dinwoodie 1996), and to all of us naturalists as the ‘deciduous trees’, with one exception (holly Ilex aquifolium) all our remaining 32 native species shed their leaves every winter (although the oaks and beech may retain a percentage of dead leaves for much of the winter period). In fact even the term ‘hardwood’ is misleading, because the wood of many deciduous trees is soft and perishable (Edlin 1944), and the most important feature is their capacity for branching in a wide variety of ways from the most points on the stem (Op. cit.). The deciduous trees may be divided into two sub-divisions: ring-porous or diffuse-porous. Ring-porous Ring-porous (heartwood) species have two distinct sizes of water-conducting vessels (i.e. two different diameters of plumbing pipes) in the xylem tissue of each year’s growth-ring (Thomas 2000). The largest diameter vessels are confined to the early-wood (lighter coloured wood formed in spring) with much smaller pores in the late-wood (darker coloured wood formed in summer) (ibid.). They therefore have rings of large pores divided by rings of very much smaller pores; ring-porous, and these can be clearly visible in some species (i.e. oaks). To cope with the inherent weakness of such large pores, ring-porous species have a very useful defence method when infected with wood-rotting fungi; the parenchyma cells in the medullary rays can form minute balloon-like obstructions out from the ray and into the xylem tubes via the minute pits in their semi-permeable sides, and by so doing block them (Watson 2006). These balloons are known as ‘tyloses’ and, whilst the defence is not impenetrable (as the pathogen can also pass through pits in the xylem tubes itself), it does slow the spread of the infection (Watson 2006). In contrast, diffuse-porous species do not have the tylose defence system, and may therefore be more vulnerable to uncontained infection than their ring-porous cousins. Diffuse-porous In contrast to ring-porous species, diffuse-porous trees have xylem piping composed of relatively uniform diameter tubes (Thomas 2000). As a result, the wood produced over a single growing season is not differentiated into early and late wood (Desch & Dinwoodie 1996), which makes the annual rings less readily distinguished (Thomas 2000). The diffuse-porous species spread their water uptake over a number of growth rings, whereas the ring-porous species concentrate their entire water uptake in the outer-most ring.

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Conifers Known to foresters as the ‘softwood’ family (Desch & Dinwoodie 1996) and to most naturalists as the conifers (because they have cones), only the larches Larix spp. shed their foliage in winter. Conifers are recognisable from a distance by the habit of most species (if only when young) of branching at regular geometric intervals. The wood of conifers is relatively homogenous, and primarily comprised of dead empty tubes known as ‘tracheids’ which serve both to support the tree, and act as the trees plumbing (Schwarze et al. 2000, Thomas 2000). In contrast to the broadleaves, coniferous trees are ‘non-porous’ as they have no pores, but instead have ‘resin-ducts’. These ducts are orientated vertically and horizontally, and are cavities in the wood lined with cells that secrete resin (Desch & Dinwoodie 1996). This resin acts as a fungicide, but not all conifers form resin ducts in healthy wood; many species (e.g. firs Abies spp.) form resin ducts only after injuries, and these are consequently known as ‘traumatic resin canals’ (Schwarze et al. 2000). It is this resin that gives conifers both their pleasant smell, and inflammable properties! N.B. Resin is not present in the true firs Abies spp., sequoia Sequoia spp. or yew Taxus baccata (Desch & Dinwoodie 1996).

WHY TREE DIVISIONS MATTER TO BATS I think it would be fair to say that in the world of bat survey there is a predisposition that broadleaved trees are good for bats and conifers are generally bad. This has led to the suggestion that broadleaved woods generally hold more tree-roosts than coniferous woodlands. However, I don’t think this is universally the case and would like to put forward the argument that a good deal of broadleaved woodland is bad for bats, and a good deal of coniferous woodland is in fact good, not for all bat species, but for some. This leads us nicely into the realms of habitat…

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TREES - HABITAT GENERAL More than any other, this Chapter is a work in progress. In December 2012 I simply ran out of time (due to a multitude of factors) and had to pull it together as an incomplete framework. I shall turn my attention to it again in the autumn when I have more time, and more money, to chase up the outstanding texts I need.

In order to be certain everyone is on the same page, I shall open with a word of warning: Wood is not wood, and woods are not woods. What does this mean? To enlighten I shall use tillage for comparison. We are often told that bats avoid tillage, yet I do not find this to be the case. It is perhaps rational to accept that bats of all species would find very little prey above a recently ploughed and tilled field that is consequently bare of vegetation, and we are therefore unsurprised with a nil result. In addition, I have found that wheat Triticum spp. generally has only the lowest levels of bat activity, and this principally confined to common pipistrelles Pipistrellus pipistrellus commuting along the field margins. Barley Hordeum vulgare, however, which often has moderate floral diversity associated with it, has generally higher activity including foraging (although again pipistrelle dominated). Moving up the scale, a potato Solanum tuberosum, turnip Brassica rapa rapa, swede Brassica napobrassica or beetroot Beta vulgaris crop is an entirely different matter and can yield surprises; when you get out into the less common you can be truly shocked; how about an abundance of Nathusius pipistrelle Pipistrellus nathusii over coriander fields in Bedfordshire, or an aggregation of serotine Eptesicus serotinus so large as to make a Duet bat-detector shiver in the palm over maize Zea mays in Hampshire. Woods are no different. Even pine Pinus spp. plantation varies in value to bats depending upon the ground flora and the age and condition of the trees, and it is those differences that determine the probability that PRF will form and, due to the productivity of the woodland structure and flora, whether individual bat species will colonise them.

INTRODUCTION I can recall about ten years ago when I first became interested in bats, hearing the throwaway remark that “…most bat-roosts are found in oak”. I seem to recall hearing this more __________________________________________________________________________________________ A8 - 1

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than once, and I certainly heard it enough for it to stick in my mind, but I do not recall hearing anyone elaborate of their own volition as to why this might be, and I didn’t stop to ask. Oak Quercus spp. has the strongest timber of our native trees, thrives on warm, south-facing slopes (Ackers 1938, Harris & Harris 1991), and is the most abundant broadleaved woodland tree in the British Isles; one third of the woodland in Britain is oakwood, no other tree approaches so high a proportion (Edlin 1956). In addition, pedunculate oak Quercus robur is the predominant wood-pasture tree (Rackham 2003). So do PRF form in equal measure in all trees, and does the suggestion that most tree-roosts are found in oak simply reflect that oak is more abundant than other tree species? Studies have suggested a tendency for pedunculate oaks to occur on moist basic soils while the sessile oak Quercus petraea favours more well-drained and acidic soils. This is demonstrated by the occurrence of pedunculate oak on lower slopes and valleys, and for the sessile oak to occur on the upper slopes and hill-tops (Morris & Perring 1974). Pedunculate oak is certainly a good Hazard-beam species as a result of its more open lowland growth, and several tree-roosting bat species like Hazard-beams. In contrast, sessile oak is a fantastic frost-crack species when in its upland woodland habitat, and several tree-roosting bat species like Frost-cracks. So which oak is the best? Or do the pedunculate oaks in the lowlands serve the maternity colony, while the males occupy the upland frost-cracks? Whatever the answer may be, historically oak was the most valuable timber tree. The general durability of oak is greater than any other British tree (Nisbet 1900). As a result it had probably the widest variety of uses from ship-building, through charcoal for fuel, and even tanning, and its value as a building material increased tenfold between 1640 and 1813 (Nisbet 1900). So oak was grown and managed in the best locations; in sheltered parks and southfacing valleys, exactly the places favoured by woodland bats. But are the bats there purely because the oak is, or is it just the environment in which the oak is growing? Taking it a step further, if the park was full of sycamore Acer pseudoplatanus, or the valley full of ash Fraxinus excelsior, could and would the same bat species roost there in the same ratio? Milner (2011) identified ash as the second most common hedgerow tree (with pedunculate oak most numerous). Do different bat species roost in hedgerow ash to those in the hedgerow oaks? Does ash develop the roost-features favoured by Natterer’s bats Myotis nattereri and noctules Nyctalus noctula, at the widely differing heights the two prefer, and if not, does another bat species dominate the hedgerows where ash trees are present instead of oak? Downy birch Betula pubescens and silver birch Betula pendula are short-lived (Milner 2011), but have a reproductive ability so great that this is of little impact to their survival (Rackham __________________________________________________________________________________________ A8 - 2

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2003). Dead birches are readily attacked from within by Polyprous betulinus and the core soon eaten away leaving only the rot-resistant bark (Rackham 2003). Could it be that roostfeatures form and fail in equal proportions, and birch is therefore favoured by an opportunist bat species, such as common pipistrelle, which make use of such roosts for only a short period in autumn for mating, returning to the same high-productivity foraging area, but occupying a new roost every year? In Trees, Woods and Man Edlin (1956) cited the presence of extensive areas of natural birch woods in the Scottish Highlands and suggested that exceptional individual trees were the survivors of a once common ‘good strain’. Milner (2011) suggests that while birches in England rarely survive more than 100 years, they often last much longer in the Highlands. Furthermore, birch in Scotland holds more invertebrates than birch in England (Shaw 1984). I have heard about bat-roosts in birch from bat-workers in Scotland, yet not heard of birch roosts anywhere else. I’m also curious about alder Alnus glutinosa and common elm Ulmus procera in Scotland. Alder is supposedly far more abundant in Scotland and a grand tree when really big (>1 m Diameter at Breast Height (DBH)), and let us not forget that the Highlands are out of range of Dutch elm disease, and both common and Wych elm Ulmus glabra are heartwood trees. Do the bats of Scotland occur in habitats that their English cousins shun? Although long-lived, sweet chestnut Castanea sativa ages quickly with rough bark, deep knot-holes and a propensity for ‘shakes’; deep cracks in the heartwood (Milner 2011). Alder too develops extraordinarily deep fissure in its bark when really big. Could sweet chestnut and alder provide roosts for individual bats in the folds of their rough bark and would such roosts appeal to specific bat species? In fact, there is a small amount of evidence to suggest that the species of tree has little if any bearing upon the bat fauna of an area. Červený & Bürger (1989) had a selection of 20 tree roosts variously occupied by Bechstein’s’ bats Myotis bechsteinii, Daubenton’s bats M. daubentonii, Natterer’s bats, Leisler's bats Nyctalus leisleri and noctules, none were in oaks, because there were no oaks in the study area, it didn’t apparently put the bats off. In addition, in their study of Natterer’s bats, Smith & Racey (2005) concurred that, as oak and ash were the most abundant trees in the area, the fact that the roosts they found were often in oak and ash had little bearing; it was the suitability of the roost-feature that was the important factor. For my part, so many of my own early experiences related to sycamore (longer living than birch and ash, but far less than oak or lime Tilia spp. (Milner 2011)), that I worried I was __________________________________________________________________________________________ A8 - 3

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misidentifying the tree! So we come back to the form of the PRF and I’ll repeat the statement I made in the Introduction: British tree-roosting bats do not make the tree features in which they roost but, while the bats may not specifically select a particular tree species for any aesthetic reason, the biology of the trees themselves dictates which roost-features are available, and the bats have almost certainly evolved to make the best of the features that are present within their favoured habitat. Woodland is not all one habitat, if it were barbastelle Barbastella barbastellus would be everywhere, and I wouldn’t spend so much time searching for Brandt’s bat Myotis brandtii in vain. For example, would it not be rational to suppose that in riparian habitat dominated by willow Salix spp. and alder, which are susceptible to heart-rot fungi, woodpecker holes may be moderately abundant and, as willow and alder do not provide a year-round source of food for squirrels Sciurus spp., there would be less competition for such sheltered refuges? Daubenton’s bats and noctules might therefore be predicted to have adopted Woodpeckerholes as their primary sites, regardless of the tree species, in response to their availability adjacent to favoured foraging habitat. After all, there would be little point in Daubenton’s bats settling upon Frost-cracks as summer roosts because willow and alder only form them very infrequently, and I have certainly never encountered one on a river-bank. Little point in noctules settling upon Frost-cracks as summer roosts either; they rarely extend above 4 m. Males and females of several tree-roosting species roost apart during the maternity period, and there is a good deal of evidence that the individual males and maternity aggregations of females typically occupy specific tree-roost forms which naturally occur at different heights. There is also a growing body of evidence to suggest that hibernation roosts are typically nearer to the ground, beneath the canopy where the microclimate is more stable. My hypothesis is that individual bat species have a preference for tree-roosts which form in abundance, or in a constant supply, in their favoured habitat and these differ both between the sexes and from season to season. In a wide-ranging review of the impact of forestry practice upon biodiversity, performed by Mitchell & Kirby (1989), it was suggested that the overriding evidence was that mammals (and birds) depend upon the stand and woodland structure every bit as much as the tree species composition. Typically, the combination of factors needed to provide a suitable roost-feature for a maternity colony comprising aggregations of bats (i.e. adequate hollow, with adequate predator-avoidance distance (sufficient internal height to be out of reach), and the favoured dome or wedge-shaped apex) are confined to older woodlands where the trees have had time to grow to a size where they drop branches, get damaged, and the various decay fungi have colonised and have sufficient hosts to persist. __________________________________________________________________________________________ A8 - 4

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It can readily be concluded that the circumstances in which a large but stable void opens up into a stem or limb, sufficient to provide a roost for a maternity-colony of bats, are relatively rare. Far less so PRF that would accommodate smaller roosts which, although by no means common to all woods, are far more widespread than I had anticipated when I first started looking; Sessile oak stored-coppice in Somerset has a particular susceptibility to frost-cracks, I have found very small diameter holly Ilex aquifolium in Dorset and Suffolk with longitudinal splits (the former due to shearing stress, the latter due to frost) leading up into fantastic elongated hollow spires, similarly sycamore form superb wound and tear-out PRF when still very young (< 30 cm DBH) and beech Fagus sylvatica succumbs to canker in similarly young stems and the young branches of older maidens. Where I refer to older I must stress that this does not necessarily mean bigger; although size is a factor, host trees do not need to be massive, or even over mature.

The PRF that may develop within a tree is significantly influenced by the habitat in which the tree grows, and the intensity of management it receives. For example, a tree in semi-natural woodland will be far more likely to sustain physical damage to the bark due to falling adjacent tree and/or limbs than a tree located in a plantation, park or isolated in farmland. In addition, the spores of wood-rotting fungi present in fallen and standing dead-wood might be predicted to be more likely to travel incrementally from tree to tree over short distances, particularly if an infected tree fell over and became hung-up in a neighbour. Roof and Buttrots certainly travel more swiftly where roots are crowded (Schwarze et al. 2000). Furthermore, the humidity under a closed canopy is far more conducive to fungal growth than a drier open habitat. In contrast, parkland trees are far more widely spaced, only very rarely with anything approaching a closed canopy, but they do typically receive more individual management such as pollarding which historically will have involved large ‘Flush-cuts’ (a practice no longer employed), which results in occlusion callus formation over desiccated and fissured heartwood. Finally, a tree located in the middle of a tilled field in a prairie-like landscape might well sustain serious damage to its root system, and this might manifest in die-back within the crown but, due to its isolation, the dead wood would be far less likely to be reached by spores of wood-rooting fungi than a tree in woodland. In this Chapter we will look at where trees grow, why they grow there, what influences their growth and form, and the intensity of management to which they will typically be subject.

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THE TREE AS AN INDIVIDUAL ENTITY Growth forms Trees fall into three common growth forms (and a much larger number of less common forms), almost all of which are influenced by man:  Coppice – Characterised by rotational cutting at ground-level for low diameter wood. Species that coppice include alder, ash, elm, hazel Corylus avellana, hornbeam Carpinus betulus, lime, pedunculate oak, sessile oak and sycamore (Rackham 1976);  Pollard – Characterised by rotational cutting between 2 – 5 m height which leaves a permanent trunk (known as a bolling). Species that pollard include ash, beech, elm, hornbeam, lime, pedunculate and sessile oak (Rackham 1976);  Maiden – A tree that is allowed to grow to its full height. The ‘standard’ is the natural form or a tree. You may notice that I don't make any reference to the hollow stems of veteran/ancient trees in this text. This is because I have no first-hand experience of a bat roost in one and could find no descriptive accounts in my review. In all but one instance the ancient trees I have encountered (and that consisted of anything more than a ring of poles) have been pollards. All are therefore relatively short (< 4 m). Where the stem resembles a chimney one wonders what use lesser horseshoe bats Rhinolophus hipposideros might make of them. The typically wide diameter void would however be easily accessible by predators. In most cases the veteran pollards I have seen have been in exposed locations in pasture, or amongst widelyspaced standards in parks, this may reduce their suitability for roosting lesser horseshoe or brown long-eared bats Plecotus auritus, and their height restrict their occupancy by species of more open ground such as Leisler’s bat Nyctalus leisleri and noctule Nyctalus noctula. I am very keen to hear from anyone who can furnish me with any accounts of bats using such trees. The Royal Parks and, famously, Staverton and Hatfield are stuffed with them, and no doubt many more places besides; someone must have some historic information lurking out there somewhere.

While management plays the most significant part in a trees development, the conditions in which a tree grows and develops will also have a bearing upon its physical form. A tree grown in open conditions will make less height growth than a tree in woodland, it will also have larger branches nearer the ground where the woodland specimen will be clear of branches to a considerable height (Desch & Dinwoodie 1996). The wood of a park or hedgerow tree will also be very different in structure from one in a woodland. Not only will the former be full of large knots from the many branches, but the rings will be wide, becoming narrow only at an advanced age (Stone 1921). In contrast, a woodland tree will be broad-ringed in its early youth but will soon reduce the width of its rings and drop redundant branches as its neighbour's crowd round and the canopy closes (Stone 1921). These differences will have a bearing upon the PRF trees hold, and at what height.

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Trees grown in open conditions tend to have PRF closer to the ground, and equally divided between the stem and larger limbs, whereas woodland trees tend to have more PRF in the stem and, whilst branch-roosts are not uncommon, they tend to be much higher in the crown. Obviously there are caveats; an oak or ash wood on a slope may hold higher proportion of trees with basal Frost-cracks and Hazard-beam stems than a woodland on level ground. But the basic principles apply; open grown trees tend to have lower PRF than woodland trees. Do not however forget that the individual tree species may be a defining factor in itself; one study (Smith 1987) found that great spotted woodpeckers Dendrocopus major make more nests in the softer and more easily excavated woods of ash, beech and hornbeam than they do in the dense and durable oak and sweet chestnut, and this may influence where the greatest densities of Bechstein's, Daubenton's and noctules occur.

WHERE TREES ARE FOUND Rackham (1976) sets out three types of situation in which trees are found:  Parks, hedges and commons – where the growing of trees is subordinate to another land use (although hedgerow and commons trees may yield both timber and wood for the landowner or commoners), characterised by wide spacing resulting in a spreading growth shape;  Woods – characterised by no (or very little) intentional planting of the ‘wood’ crop, where the trees are of different ages and species, and often different heights, still with a closed canopy, but often over a varied shrub-layer; and  Plantations – characterised by deliberate planting (often in straight lines) of a ‘timber’ crop. Typified by trees of all one age group, either a single species (or if others occur one is by far the dominant species), and one height, in a closed-canopy with little or no shrublayer. This appears a perfectly sensible division and it’s the one I have adopted. I have not however produced a separate 'commons' account, as all the trees I know of on commons are in woodland. In addition, it should be noted that isolated trees within pasture and particularly tillage, are very often a remnant of a long-since grubbed out hedgerow.

PARKS, HEDGES & COMMONS General Trees grown in more open habitat, such as hedges, parklands and coppice (and the standards in coppice) grow quickly and have a higher proportion of their wood in the branches (Bisch __________________________________________________________________________________________ A8 - 7

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& Auclair 1988). The stage where they have large dead branches and holes suitable for nesting birds would therefore be reached sooner than a tree of comparable age in woodland (Mitchell & Kirby 1989). In their race for life, plantation and woodland trees put their energy into upward growth, with little expended upon lower branches. In contrast, an isolated tree can maximise its productive surface area by growing up and out in a more spherical fashion, and the further it grows out, the greater the chances that stress-fractures may occur. Open grown trees would (in theory) be more pre-disposed to Hazard-beams and PRF in lateral and vertical limbs, than a forest tree. However, a species grown in the open will have a wider zone of sapwood, than the same species grown in a wood (Desch & Dinwoodie 1996), and the ratio of sapwood to heartwood may also have a bearing upon strength when hollow, particularly in lateral limbs (Desch & Dinwoodie 1996).

Ornamental parks Ornamental parks may contain both broadleaved and coniferous species, the latter of which will in many cases be entirely unrecognisable from their plantation brethren; pines in particular develop rugged, irregular upper branches which may be very similar in outline to a broadleaved tree (Edlin 1976). Simms (1971) observed that big old mature pines often bear deep and irregular fissures. The inner structure of a tree grown in open conditions, such as a park or hedgerow, will be different from a tree of the same species in a plantation or wood. While a plantation or wood grown tree may have wide annual rings in relation to its diameter when young, as the canopy closes in around it, the width of the rings will contract (Stone 1921). Wide rings imply dense wood in ring-porous broadleaves (the Heartwoods), and lax wood in conifers, with no distinction in the diffuse-porous broadleaves (Stone 1921). This situation would appear to suggest that a Heartwood tree in open conditions would be stronger, and more resistant to decay than the same species in a wood, but not so a conifer which would in fact be softer. City parks: A study performed in London in the 1980’s (Mickleburgh 1987) recorded four tree-roosting species comprising Brandt’s bats Myotis brandtii, noctules Nyctalus noctula, pipistrelles Pipistrellus spp., and brown long-eared bats Plecotus auritus in the city, with roosts of Daubenton’s bats Myotis daubentonii also recorded in the outer suburbs. Whether the roosts were in buildings or trees is not set out in the paper, but it does at least show that tree-roosters are present in centres of human habitation and might therefore colonise suitable PRF in a city park.

Heart-rot is particularly prevalent in parkland due to chicken-of-the-woods Laetiporus sulphureus (Cartwright & Findlay 1958).

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Wood pasture Wood pasture can be broadly divided into two forms:  Lowland wood pasture: Derived from medieval hunting forests (Harmer et al. 2010) and typified by large maidens over sheep-grazed pasture within sight of a stately home; and  Upland wood pasture: Historically provided shelter for grazing animals and wood for rural communities (Harmer et al. 2010). Typified by pollard oaks. Oak is the most suitable tree for parks and pasture lands (Nisbet 1900), and wood pastures are typically where you find veteran oaks. In wood pasture the trees are typically pollards, cut periodically at 3 – 4 m height in order that the new growth escaped browsing by livestock (Rackham 1995). Some supposedly ‘ancient’ woodlands are particularly disappointing in the number and range of PRF their trees hold, and a chance observation by Rackham (1995) who describes a Planted Ancient Woodland Site in Ireland known as Tomies Wood, which was ‘replaced’ in 1805 with even-aged genetically uniform plantationlike oaks, hints at why some superficially semi-natural woods are poor for bats.

Hedges Hedgerow may be considered linear woodland, and hedgerow trees viewed as standards over linear coppice (Morris & Perring 1974). The most common of the hedgerow trees were historically elm, oak and ash in that order (Nisbet 1900); their individual growth habits limiting where they were planted. Nisbet writing in 1900 cited oak as the best of hedgerow trees, for “…it neither robs the soil of food for the crops, nor tend to hinder the plough by throwing out long shallow roosts like ash and elm.” The long surface roots of ash were a nuisance to the ploughman (before monster tractors made the difference irrelevant) and so ash tended to be planted on meadow and pasture hedges, where oak and elm could be planted in either grassland or tillage. Common elm in particular was a most versatile tree and “most commonly to be found along country lanes and mong the hedges, where it throws up abundant suckers, giving free choice for standards at convenient distances” (Nisbet 1900). A little over 100 years ago Nisbet (1900) discussed the need for a change in the way trees were grown, suggesting that there was a “…chronic want of long clean [oak] stems undamaged by branch knots”. Nisbet (1900) argues that the practice of growing timber oaks in parks and on hedgerows (or over copse), in order that they develop the outstretched branches suitable for the crooks and ribs of ships, was no longer a profitable enterprise (presumably because the days of wooden ships were known to be numbered). The hedgerow oaks however remain. I have often wondered why they were allowed to __________________________________________________________________________________________ A8 - 9

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develop to such size and then gradually collapse, when the hedge beneath had been flailed into a manageable shape and height. A good many hedgerow oaks pre-date Mr Nisbet’s book, but one can only speculate on why such a valuable crop of timber was left to rot in the fields. But this is all the better for bats, weasels, stoats, foxes, birds and a multitude of invertebrates I suppose.

WOODS General We tend to think of woods as 'high-forest' (or copse), 'coppice with standards' or 'coppice' but in fact these are management methods, not woodland definitions. Luckily however Simms (1979) clarified the situation with the following definitions of woodland:  Wood: Tree-covered area of over 2 ha;  Grove: Small wood from 0.2 – 5 ha in extent;  Clump: Cluster of trees of less than 0.2 ha in extent;  Belt: Strip of trees less than 20 m wide but of indefinite length;  Line: Single or double line of trees with their canopies touching or nearly so;  Stand: Area of woodland, 0.4 ha or more in area, which is uniform for the purposes of description. Many woodlands can be sub-divided into stands;  Scrub: Regenerating woodland composed of bushes and trees no taller than 8 m;  Spinney: Thorny plants (pure or mixed) of hawthorn Crataegus monogyna, blackthorn Prunus spinosa or bramble Rubus fruticosus agg. Typically planted as game coverts; and  Carr: Fenwood of alder or buckthorn Rhamnus cathartica with extensive scrub growth of sallow Salix caprea, hawthorn, spindle Euonymus europaeus, privet Ligustrum vulgare and currant Ribes spp. Within woodland a further distinction is made between the structural heights:  Ground layer – 0-50 cm;  Field layer – 0.5 – 2 m;  Shrub layer – 2 – 5 m; and  Canopy – 5 – 30 m (AA 1973). These distinctions may seem irrelevant, but actually they’re important because individual bat species have preferences for how deep within woodland they go, often reflecting where they forage and the hunting strategy they use; typically gleaning or hawking. Is it not therefore possible that certain bat species might typically roost (if only the maternity aggregations) within woodlands above a certain size? Is it possible others prefer far smaller areas of woodland? I once did a September bat survey in intensively farmed tillage in Bedfordshire in which every field corner had a clump, offset as a diamond to the fields themselves, and joined __________________________________________________________________________________________ A8 - 10

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by hedgerows. I had eight of these clumps in my site and all had individual singing common pipistrelles in them; just one bat, holding its own little territory in all eight tiny woods (this was before I learnt to climb, so I never did know whether the bats day-roosted in the trees). Now I’m not saying you wouldn’t get eight males in single woodland, but I wonder how far apart they would typically occur, and therefore how big a single area of woodland would need to be to support all eight of them? Whilst it’s improbable that a tree-roost would occur in a spinney, it’s not impossible, and until records are made with sufficient resolution, we won’t begin to see patterns that might further guide search effort. Management Historically woods were for the production of just that; wood: “poles and branches of trees of smaller diameter than timber.” (Rackham 2003). Large veteran/ancient trees are therefore not characteristic of ancient woodland (Rackham 1995) Nisbet (1900) describes the two sorts of woodland crops (yes, trees were planted as a crop too, just like plantations, and just like wheat, barley, maize and the rest) recognised within the ancient English Forest Charters and statutes; highwoods (Boscus) and underwoods (Subboscus). Boscus gradually evolved into ‘copse’ (otherwise known as ‘stored coppice’ and what we think of as semi-natural woodland) and ‘coppice with standards’. Subboscus into coppice. It seems extraordinary now, but in Nisbet’s day the value of a mature standing crop of oak would exceed the freehold value of the land.

Copse Copse or ‘stored coppice’ was historically cited as an excellent method for growing large and valuable oak, ash and larch Larix spp. (Nisbet 1900), and comprised a small compartment of woodland, of a single timber species over an understorey of ash, sycamore, maple Acer spp., hazel, beech etc. (Op. cit). Unlike coppice with standards where the oaks were open grown to provide the bowed limbs necessary for ship-building, Copse was closed-canopy woodland where the timber was produced in close groups to produce straight stems for construction i.e. oak for lock-gates, barns, and houses etc. Those little Copse woodlands were the forerunner of commercial plantation forestry, and much of the oak and ash woodland we enjoy today as semi-natural, is just Copse that has fallen out of management and never been harvested.

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Coppice Coppice: a wood consisting of shoots which have regenerated from the stumps or ‘stools’ of felled trees (Hanson 1934). Coppice is familiar to most mammal enthusiasts as the hazel stools with slender stems in which we site our hazel dormouse Muscardinus avellanarius boxes. Historically coppice had a much wider scope however, and included ash, sessile oak, chestnut, alder, sycamore, hornbeam and birch (James 1982) which were managed in rotation and divided into coupes equal to the number of years in the management rota (Harmer et al. 2010). By dividing the woodland up in this way a coupe could be cut each year to provide a constant resource. Whilst brown long-eared bats Plecotus auritus are regularly found in dormouse Muscardinus avellanarius boxes in hazel, I think I can say, without too much risk of contradiction, that hazel does not readily form PRF. This may have led Goldsmith (1992), citing Mitchell & Kirby (1989) to suggest that coppice woodlands were only likely to hold tree-roosts where older broadleaved trees were present. This suggestion would be entirely reasonable if all coppice woodlands were hazel and under management. It is certainly misleading when applied generally; sessile oak coppice woodlands in Somerset hold the highest density of tree-roosts I have ever encountered. Why are brown long-eared bats Plecotus auritus found in low-level dormouse Muscardinus avellanarius boxes? How do they find them? Do they perhaps hibernate in hazel-stools like dormice?

When the market for coppice diminished a good deal of it was simply left to its own devices, often incorrectly labelled as ‘stored-coppice’ these abandoned woods can be fantastic for PRF. Outgrown stored-coppice stems are under all sorts of stresses that render them liable to fractures. For example, a good deal of oak coppice was grown above charcoal pits, on steep slopes in narrow valleys. This location and lack of management at once puts them at significant risk of frost-cracking and also the development of hazard-beams in the stems.

Coppice with standards Coppice with standards: a wood which consists partly of maiden trees which form an overwood and partly of coppice stools which form an underwood (Hanson 1934). The coppice with standards system is a mix of understorey with widely-spaced standards worked into the stock; typically pedunculate oaks (James 1982). The idea being to maximise space but, more importantly, to provide a regular income from the coppice in the interim period the valuable timber crop will take to reach maturity. Compartments of coppice with standards can be superb for bats. Where the woodland has __________________________________________________________________________________________ A8 - 12

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been left (often on estates still managed for game fowl) the standards may be found to be approaching veteran status and, despite their original selection as good timber stock, may now be becoming susceptible to die-back in the crown and the attentions of invertebrates, fungi and finally birds. In addition, three dimensions of canopy, shrub and herb-layer are more balanced than in high forest, resulting in superb foraging habitat for woodland bats.

PLANTATIONS General Writing in 1900 John Nisbet stated that “the main object of commercial forestry is to obtain the largest and most profitable returns from the land in the shape of a regular yield sustained annually”. Plantations are planted strictly for timber: “trunks or trees, of more than a certain diameter, suitable for making beams or sawing into planks…” (Rackham 2003). Nisbet (1900) urged that only by growing oak and all other trees more closely together than had hitherto been customary in Britain, could the English oak be controlled so as to direct its energy towards the formation of a long clean bole, free from the thick branches that cause knots. Reference to Mr. Nisbet’s book Our Forests and Woodlands suggests this was not an entirely new idea, a photograph of an oak plantation shows trees of about 20 years of age at c. 1.5 m spacing and looking identical to a modern spruce of pine plantation; a more ‘industrial’ looking woodland you would be hard-pressed to find! Plantations are managed to be continuous tracts of ‘high forest’: a wood consisting solely of trees raised to be maidens or standards (Hanson 1934). A such plantations are wholly artificial woodlands, comprising trees of uniform age planted in straight lines, typically in ‘compartments’ which are management units of approximately 10 ha (Simms 1979). Plantations comprise the vast majority of tree-cover in the British Isles and a good deal of it was performed within the last 100 years (Hibberd 1991). Even superficially natural forests may have a plantation origin (ibid.). Whilst we tend to think of non-native conifers when we think of plantations, broadleaved plantations are also fairly common and may comprise species recognisable as native. However, the provenance of plantation crops is often continental (as has been highlighted by the recent ash dieback Chalara fraxinea outbreak). Furthermore, the vast majority of plantation trees don’t even come from seed with a natural origin, but are grown in forest nurseries. Tree breeders have spent decades selecting the best breeding stock to improve the most important adaptive and economic characteristics such as vigour, timber quality and disease resistance (Hibberd 1991). The strain of tree can even be specifically chosen for the geographic location and environment into which it is to be planted __________________________________________________________________________________________ A8 - 13

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(Thompson 1995). Even oaks are subject to this level of control, with mature trees exhibiting good and bad characters selected, cloned, and used in experiments to judge what influences are at work (Hibberd 1991). By so doing, the most economically important characteristics (including resistance to frost, insects and fungal infection) can be improved. This breeding has been going on for nearly 60 years and includes managing genetic diversity to identify superior genotypyes, and the propagation and deployment of genetically improved material (Thompson 1995). How’s this for a conference talk; Prospects for advanced vegetative propagation and genetic modification of forest species (Douglas 1995). Good news for Schwegler, not such good news for bats; it might be a good idea to start planting out some Staverton acorns somewhere now…

Management In the 1930’s, when a good deal of the plantation woodland maturing today was planted, or about to be planted, the important species were Sitka spruce Picea sitchensis, European Larch Larix decidua, Japanese Larch Larix kaempferi, Douglas fir Pseudotsuga menziesii, Scots pine Pinus sylvestris, Corsican pine Pinus nigra, sycamore, ash, pedunculate oak, sessile oak and sweet chestnut (Hanson 1934). In 1991 this list had been expanded to include Norway spruce Picea abies, beech and hybrid poplars Populus spp., but otherwise remained the same (Hibberd 1991). High forest plantations may be divided into ‘pure’ stock with compartments comprised of a single typically coniferous species, or ‘mixed’ stock where the compartment contains two or more species; typically broadleaves grown to complement each other by influencing mutually beneficial growth (Hanson 1934). When the compartment is established it is stocked with seedling trees or (less often) seed at close spacing. The trees are then left to grow passing through a succession of growth stages comprising:  Thicket stage – the stage after planting when the young trees form a dense thicket or clump;  Pole stage – the stage when the young trees resemble tall, thin poles; and  Mature stage – the stage where the trees have reached the point where it is financially optimal to harvest them (Lane & Tait 1990). Management at the thicket stage is limited to pest-control (principally rabbits Oryctolagus cuniculus, squirrels and weevils), and weeding out of competitive species, such as bramble and rhododendron Rhododendron ponticum. By the pole stage, the close grouping of the trees shades out the lower branches, so by the time the tree is nearing maturity all the branches up to 5 m are dead or dying (Ackers 1938). In order to reduce the number of knot-holes (which affect the value of the timber) and to facilitate inspection of the trees by a forester on foot, the __________________________________________________________________________________________ A8 - 14

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trees are ‘brushed-up’ when they are between 14 and 18 years of age. Brushing-up is the removal of lower branches up to 2.5 m (Ackers 1938). The crop of young trees is then thinned in order that overcrowding does not occur. Thinning The management of coniferous and broadleaved plantations has one key difference; in coniferous plantations the importance of individual trees is secondary to overall volume. As a result thinning is most often performed by machine with no prior survey to ‘weed’ out the ‘wolf-trees’ (misshapen trees) i.e. the machine operator simply chugs through the compartment removing every third row. In contrast, broadleaved plantations are subject to careful ‘selective thinning’ where trees are removed or retained on their individual merit, with thinning targeting the poorest stems. Back in 1900 the thinning of broadleaved plantation was a very detailed job, with any tree showing signs of disease removed (Nisbet 1900). In summary, conifer thinning is more a matter of intensity where broadleaved thinning is a matter of careful tree selection (Hibberd 1991). Hibberd (1991) sets out criteria for selective thinning comprising:  Good stem form and freedom from defects in the lower bole;  Absence of deep forking in the crown;  Good vigour;  Freedom from defects such as squirrel damage and fungal infection; and  Low incidence of epicormic branching. It can readily be seen that the selective thinning of broadleaves aims to avoid all natural features such as knot-holes which significantly reduce the value of the timber. As Ackers (1938) pointed out, the forester has “…three main troubles: the first is knots, the second is knots, and the third is knots”. Furthermore, improving the productivity of forests is the main objective of modern intensive forest management (Thompson 1995). As most of the commercially important diseases of trees are caused by fungi (McCracken 1995) plantation management seeks to eradicate wood-rotting fungi in order that the financial value of the crop is maximised. Cartwright & Findlay (1958) sum up their advice in relation to decay thus “one may say that it is always best to fell trees infected with heart-rot as soon as feasible… where financial considerations allow, stumps attacked by [wood-rotting fungi] should be grubbed up and burnt and the fruit bodies of [the] fungi collected and burnt.” Such careful thinning would be likely to result in the removal of all trees holding PRF in a broadleaved plantation. Not so the conifer plantation, which is more machine orientated. Whilst most forestry does still involve the removal of damaged, moribund or dead trees in order to control the spread of fungal diseases (Stebbings 1998), Watson (2006) highlights that while plantation __________________________________________________________________________________________ A8 - 15

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management focusses on the production of straight single stems, nevertheless many doubleleader stemmed individuals slip through the management regimes. The same is true of a good deal of wood-rot fungi, particularly the butt-rot specialists which may in fact be more common in conifer plantations than anywhere else. Mitchell & Kirby (1989) set out an interesting review of the shading effect of various conifer crops upon the shrub and herb-layer. They suggested that:  pines Pinus spp. typically have a diverse vertical structure with a good shrub and herb-layer;  larches Larix spp. and Douglas fir Pseudotsuga menziesii also have a diverse vertical structure, and although they can eliminate the shrub/herb-layer a the thicket stage it returns later; and  heavy shade-casters, which include the spruces Picea spp., firs, western hemlock Tsuga heterophylla, western red cedar Thuja plicata and Lawson’s cypress Chamaecyparis lawsoniana, have a uniform vertical structure and eliminate the shrub and herb-layer at the thicket stage, with little returning later.

It is perhaps interesting that the accounts I’m hearing from the field suggest Corsican pines Pinus nigra, Douglas fir and the larches are some of the best roost tree species, whereas I cannot find a single roost account for the latter group. Harvesting In most cases the crop is felled before biological maturity is reached (Hibberd 1991) Principal height-growth ceases at different points depending upon the species, with harvesting following soon after:  Oak: harvested between 100 to 130 years;  Beech: harvested between 90 to 100 years;  Ash, maple, sycamore and chestnut: 60 to 80 years; and  Conifers 40 to 80 years (Hanson 1934, Thompson 1995).

WHY HABITAT MATTERS TO BATS In 1910 Barrett-Hamilton wrote "many bats alter their feeding grounds with the season, since they must perforce attend the migrations of their prey. Rivers and pools, lanes and hedges, ivy-covered walls and ruins are all sought at the times when they most attract insects, knowledge of the habitats and lights of which is essential to a bat-hunter." "Others alter their beats but little throughout the year, but none is more regular than the Pipistrelle – which may be encountered night after night on the same restricted course." In 2012 we have a general idea of which bat species occur in which habitats. Thanks to Greenaway (2001) and Billington (2004), amongst others, we now know that barbastelle roost almost exclusively in semi-natural broadleaved copse. Thanks to Flanders & __________________________________________________________________________________________ A8 - 16

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Hill (2004) we know the same can be said for Bechstein's bat. The suggestion from the Continent is that Brandt's bats appear to favour carr woodland (Taake 1984). Daubenton's bats favour trees on river-banks, or woodland adjacent to rivers (Altringham 2003). Thanks to Smith (2001) we know that Natterer's bats roost in broadleaved woodland, tree-lines and hedgerows, but thanks to Mortimer (2005) we also know they roost in double-leaders in Corsican pine and Douglas fir plantations. Thanks to John Haddow and Stuart Spray we know Leisler's bats roost in parkland trees of a variety of different species, but including Scot's pine (J. Haddow 2012 pers. comm., March). I've found noctules in parkland, a garden and hibernating in dense woodland (but only present when the foliage was down). On the Continent they find Nathusius’ pipistrelles in all forms of woodland, but always close to open water (Boye & Dietz 2005). We know from David Dowse that common pipistrelles turn up in wood-pasture type habitat (D. Dowse 2012, pers. comm., January), and from Richard Koczy that soprano pipistrelles Pipistrellus pygmaeus have been found hibernating in a Douglas fir plantation (R. Koczy 2012, pers. comm., November). And last, but not least, we know that brown long-eared bats favour open woodland in river valleys (Entwistle et al. 1997), but move out onto hedgerows in the autumn (Murphy et al. 2012). What we need to do now, is to begin bottoming-out the detail of exactly which influences are important within the individual habitats in terms of tree species, structure, historic and current management, so we can really begin to target our effort. I hope that by providing this review, and the entirely rational definitions it contains, a greater focus will now be given to the wooded habitats in which tree-roosts occur. In addition, it is hoped that amateur naturalists and ecological consultants alike, will be encouraged to assign a greater degree of resolution to the accounts they make in the field. However, as I said at the start of the Chapter, there is more to add to this text in the short term and particularly in relation to seasonal variations in habitat exploitation by individual bat species. ______________________________

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TREES – WOOD GENERAL Trees are composed of a substance that persists over winter, allowing a continuation of growth in the following year rather than a reproduction of the previous (e.g. bluebell Hyacinthoides non-scripta etc.). This substance is of course; wood. Wood, according to Wikipedia is “a natural composite of cellulose fibres (which are strong in tension) embedded in a matrix of lignin (which resists compression)”. “In a living tree [wood] performs a support function enabling ‘woody’ plants to grow large”. I like this explanation; it’s pithy (pardon the pun) and I can understand it. However, its simplicity hides a slightly more complicated situation; ‘wood’, like ‘bats’ is not all the same thing. But surely wood is, well, wood? Well yes, but actually no, the situation is a lot more complicated; the properties of wood differ from one tree species to another, and no two are exactly the same. Some tree species are slow-growing but, once they attain sufficient size to beat off the competition, are typically long-lived, while others reproduce on a vast scale and specialise in swift growth at the expense of durability (Mattheck & Breloer 1994). As a result not all woods perform in the same way under duress from environmental stresses and fungal attack. Take a moment to close your eyes and think of the last time you saw a really big, dead oak Quercus spp., bark peeling in huge plates, wood bleached by the sun with spreading branches deeply fissured by desiccation; quite a common sight for most of us. I’m sure many people can still recall the aftermath of the last bout of Dutch elm disease which left many tall bleached monoliths in hedgerows, and some of you may also be familiar with the spiralling heartwood of dead sweet chestnut Castanea sativa. I’ve recently seen several groups of standing dead hornbeam Carpinus betulus and horse-chestnut Aesculus hippocastanum in Hatfield Forest but all are recently dead, and it’s the first time I’ve ever seen one that wasn’t on its side and as soft as sponge. I’ve seen plenty of dead beech Fagus sylvatica but, aside of one standing monolith, all the rest had entirely collapsed. I’m sure we’ve all seen plenty of dead birch Betula spp., but I’m equally sure none of us would want lean against one. I’ve certainly never seen a standing dead beech or a birch that was as hard and strong as the oaks and sweet chestnut, have you? Even the pines Pinus spp., though they may stand dead long enough to lose the bark entirely, soon succumb to weather and invertebrate attention and collapse. I have illustrated this to a colleague recently during a felling by finding a dead and naked Scots pine Pinus sylvestris with a Diameter at Breast Height (DBH) in excess of 50 cm, which I rocked and tipped over in a matter of moments! The durability of oak is well known, but according to Nisbet (1900) “no timber grown in our woods can compare with [ash Fraxinus excelsior] in toughness and elasticity”. In contrast, Nisbet said that beech “…has none of the sublime qualities of majesty and of endurance for many centuries against the destroying tooth of time” and cited Gilpin, who in 1791 wrote that the wood of beech was of a “soft, spongy nature; sappy, and alluring to the worm.” John Evelyn wrote in his Sylva of 1664 that birch “be of all other the worst of timber” and, more __________________________________________________________________________________________ A9 - 1

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recently, Mattheck & Breloer (1994) suggested that when compared with the slow-grown strength of oak, swift growing and less durable woods (which include birches, poplars Populus spp. and willows Salix spp.) appear to have something of a ‘throw-away’ mentality. But if all trees are of an identical chemical composition comprising exactly the same sort of woods, then why don’t all species of tree disintegrate at the same rate when they die? Well, in broad terms, it’s because tree species don’t all have the same composition, and the nature of the xylem and its resistance to decay varies on a sliding scale. Edlin (1944) suggests that at a given point in a trees development, the tree reaches a point where the conductive tissues within the stem exceed both the needs of the foliage in the canopy, and the needs of the roosts below. At this point, any expansion in the crown will logically require a greater mechanical strength to hold it up. As the tree already has a surplus within the tissue, it can afford to close up a portion of the wood vessels in the core of the stem, and convert them into stronger mechanical tissue. At this stage they cease to carry sap and are no longer sapwood, but instead are much stronger and more durable heartwood. But, we already know that tree species divide into ring-porous, diffuse-porous and nonporous categories, and these distinctions define the ageing process within the wood as the tree grows up and grows old. So, whilst all trees begin life entirely composed of ‘sapwood’, which Stone (1921) defines as “that portion of the tree which maintains its vital activity” and this vitality is greatest within the most recent outer layers (the reason why all trees may be killed by being ‘girdled’; having a ring cut all around the stem), as different species of trees age they exhibit idiosyncrasies inherent to the central column of older growth, and these idiosyncrasies can in fact be divided into three broad categories:  Heartwood species;  Ripewood species; and  Sapwood species (Stone 1921). Unfortunately I couldn’t find any one conclusive description, supported by scientific study, of exactly what the true situation is in relation to disease resistance, and which species fall into which category. So readers take note:

Unless a specific sentence is supported by a bracketed reference, the following Chapter is my interpretation of what I think is going on based on the information I have found. The text is therefore, to a great extent, a common sense hypothesis rather than a statement of fact. Heartwood It would appear that on the upper end of the disease-resistance scale, the older cell walls on ring-porous broadleaved species are coated with rot-resistant tannins and the pores blocked with mineral deposits (Stone 1921), meanwhile several non-porous coniferous species have cells filled with resins, and these are the true ‘Heartwood’ species.

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Ripewood Further down the scale, the diffuse-porous broadleaved species would appear to have far less in the way of tannins, but what is present is within the cell walls (Stone 1921). In addition, some non-porous coniferous species do not have resinous wood at all (Desch & Dinwoodie 1996). These are the so-called Ripewood species. Sapwood Finally we come to the least rot-resistant specimens, which I deduce to comprise diffuseporous broadleaves in which the small amount of tannin present is accumulated in the cavities of the cells (Stone 1921). This last group either do not form Ripewood at all, or comprise species that typically do not attain sufficient age/girth for the central column to die and become Ripewood. These would appear to be the so-called Sapwood trees where all the wood in the stem is alive and vital. The relationship between wood-rotting fungi (and their individual infection strategies) and the category of tree, has a bearing on how quickly rot will develop. This is the reason why decay by the same fungus will progress at different rates, depending on the tree species (Schwarze et al. 2000).

HEARTWOOD In Heartwood species the older rings inside the tree die in succession from the core outward. The death within the individual ring is quick, occurring over a single year, but ring deaths are irregular; taking place at different rates in different periods; at one time exceeding newgrowth, at another lagging behind it (Stone 1921). Once Heartwood formation is complete the wood is technically dead (Hanson 1934), the visibly darker heartwood serving only for support (Edlin 1956). However, when the ring dies it also undergoes a chemical change, with the previously open cells becoming impermeable to moisture, and more resistant to the attacks of insects and decay (Stone 1921, Desch & Dinwoodie 1996). These chemicals are known as ‘extractives’ (so called because they can be extracted from the wood with solvents (Edlin 1956)) and include tannins in broadleaves and resins in conifers (Edlin 1956). These extractives may be water-repellent and are toxic to fungi (BRE 1998), although some fungi (e.g. Fistulina hepatica) are tannin specialists and the presence of tannin may actually promote their growth (Schwarze et al. 2000). The cell cavities of broadleaves may, however, also become blocked with mineral deposits (Bonham 1934) which may retard the progress of fungal hyphae through the tree. In addition, ring-porous trees have the advantage of the tylose defence mechanism described in the previous chapter. Although, when seasoned, heartwood is more durable than sapwood, in its natural state (i.e. in the growing tree) the heartwood is the more prone to decay of the two (Edlin 1976).

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Stone (1921) cites the work of Hartig (1891) who claimed that in the broadleaves all the Heartwood species are ring-porous. I have found no subsequent contradiction to this suggestion and, if this is indeed the case, the Heartwood trees common to the British Isles comprise: Wych elm¹ + ² + ³ Ulmus glabra; Common elm¹ + ² + ³ Ulmus procera; Sessile oak¹ + ² + ³ Quercus patraea; Pedunculate oak¹ + ² + ³ Quercus robur; Ash¹ + ² Fraxinus excelsior; Wild cherry³ Prunus avium; White poplar¹ Populus alba; Sweet chestnut¹ + ² Castanea sativa; Scots pine¹ + ² + ³ Pinus sylvestris; Corsican pine¹ + ² + ³ Pinus nigra; Western hemlock Tsuga heterophylla; Larch² + ³ Larix decidua; Douglas fir² Pseudotsuga menziesii; Cedar of Lebanon² Cedrus libani; Deodar² Cedrus deodara; Atlas cedar² Cedrus atlantica; Western red cedar² Thuja plicata; and Yew² Taxus baccata. ¹ Wood category placing supported by Stone (1921). ² Wood category placing supported by Edlin (1944). ³ Wood category placing supported by Schwarze et al. (2000).

RIPEWOOD In Ripewood trees the death of the individual ring is gradual, with the ring slowly losing conductivity and vitality over several years before finally dying. The death does not result in any chemical alteration to the wood (Stone 1921) and the trees (being diffuse-porous) do not have the tylose defence mechanism (Watson 2006). Ripewood is therefore far more susceptible to significant and unchecked decay of the core following injury. Note: due to disparities within published accounts, the limes Tilia spp. and the spruces Picea spp. appear in both Ripewood and Sapwood lists. The Ripewood trees common to the British Isles comprise: Beech¹ + ² + ³ Fagus sylvatica; Hornbeam² Carpinus betulus; Hazel Corylus avellana; Black poplar² Populus nigra; Lime³ Tilia spp.; Alder² Alnus glutinosa; Grey poplar² Populus x canescens; Rowan Sorbus aucuparia; Holly² Ilex aquifolium; Field maple² Acer campestre; Crack willow Salix fragilis; __________________________________________________________________________________________ A9 - 4

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Horse chestnut² Aesculus hippocastanum; Cypress² Cypress spp.; Sitka spruce³ Picea sitchensis; and Norway spruce³ Picea abies. ¹ Wood category placing supported by Stone (1921). ² Edlin (1944) does not specifically refer to the noted species as ‘Ripewood species’ but I have made reference to this text as it does specifically state that the noted species have no Heartwood. ³ Wood category placing supported by Schwarze et al. (2000).

SAPWOOD Some diffuse-porous species can keep over 100 rings alive and (whilst they may exhibit decreased conductivity) all the cells remain alive for the life of the tree right through to the core (Thomas 2000, Huttunen & Heikkila 2001); these are the so-called Sapwood species. Their vitality might suggest that Sapwood trees would be the strongest of the three forms whilst alive. However, most wood-decay fungi specialise in either Heartwood or Sapwood and, as there is only one form of wood to contend with, having infected a sapwood tree they are able to spread throughout the tree from the core to the bark without any opposition (think of the cardboard birches so often encountered - I once found one that had been entirely hollowed into a tube and colonised by wasps in a 4 m high cylindrical nest, in fact it was only the nest keeping it up!). A good many Ripewood species are comprised of Sapwood throughout until they reach middle age; alder Alnus glutinosa in particular has a thick sapwood layer and appears only to begin forming Ripewood when it has reached c. 30 cm DBH (H. Andrews pers obs.).

The Sapwood trees common to the British Isles comprise: Silver birch¹ + ² + ³ Betula pendula*; Downy birch¹ + ² + ³ Betula pubescens*; Lime¹ + ² Tilia spp.; Aspen³ Populus tremula; Goat willow¹ Salix caprea; Grey willow¹ Salix cinerea; White willow¹ Salix alba; Sycamore¹ + ² + ³ Acer pseudoplatanus; Holly² Ilex aquifolium; Sitka spruce Picea sitchensis ¹ + ²; and Norway spruce Picea abies ¹ + ². ¹ Wood category placing supported by Stone (1921). ² Edlin (1944) does not specifically refer to the noted species as ‘Sapwood species’ but I have made reference to this text as it does specifically state that the noted species have no Heartwood. ³ Wood category placing supported by Schwarze et al. (2000). *The birches are also known as ‘False-Heartwood’ species. False-heartwood has the appearance of Heartwood but it is so depleted of the elements essential for life that few organisms grow in it (Shigo 2000). As a result, False-heartwood has some resistance to fungal infection and invertebrate attack as there is nothing left for the beasties to feast on. It is associated with dead branches where it extends in a longitudinal direction in the stem below the dying branch attachment and may for a column where many branches die in succession (Philips 2008). __________________________________________________________________________________________ A9 - 5

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BIOLOGICAL NATURAL DURABILITY The presence of natural fungicides within heartwood trees protects against decay, whereas all the wood of sapwood trees (e.g. birch) is usually broken down very rapidly and extensively (Schwarze et al. 2000). As a result fungi such as Phellinus robustus (so favoured by woodpeckers) rot the wood of poplar and willow very quickly, hornbeam less quickly, and oak and pine wood slowly (Golovko 1986). But alas the complexities don’t end with just three categories. Even within the individual Heartwood, Ripewood and Sapwood categories, the individual woods exhibit wide differences in their resistance to decay, or ‘Biological Natural Durability’ (BRE 1998). Biological Natural Durability (BND) is defined by the Building Research Establishment (BRE) as “the ability [of timber] to resist attack from wood-destroying fungi” (BRE 1998). In their research into the durability of cured timber for construction purposes, the BRE graded the wood from the individual tree species into five classes comprising:  Very durable – mean life (years) greater than 25;  Durable – 15 to 25 years;  Moderately durable – 10 to 15 years;  Non-durable – 5 to 10 years; and  Perishable – up to five years (BRE 1998). The ring-porous Heartwood species range widely in their durability with the oaks in the ‘very durable’ class, the true cedars Cedrus spp., western red cedar Thuja plicata and yew Taxus bacatta in the ‘durable class’, sweet chestnut and larch Larix spp. falling within the ‘moderately durable’ class, the elms Ulmus spp., aspen Populus tremula, pines, western hemlock Tsuga heterophylla and Douglas fir Pseudotsuga menziesii all within the ‘nondurable’ class, and finally ash falls within the ‘perishable’ class. The diffuse-porous Ripewood and Sapwood species fare far worse however, with all but the ‘non-durable’ cypresses Cupressus spp. and spruces falling within the ‘perishable’ class. Whilst it is accepted that these classes relate to felled and cured timber to be used in construction, they do (I think) give a good idea of just how resistant to decay the different tree species are following infection by a wood-rotting fungi and it also suggests why oaks appear to retain roost features for so much longer than other tree species.

WHY WOOD MATTERS TO BATS Whether a tree species forms Heartwood, Ripewood or retains Sapwood throughout its life has a bearing upon decay resistance and that in most cases heartwood trees decay as a slower rate than Ripewood and Sapwood trees. Heartwood trees are therefore likely to remain structurally stronger for longer when dead or dying. Furthermore, the differences in the structure and behaviour of Heartwood, Ripewood __________________________________________________________________________________________ A9 - 6

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and Sapwood may have a bearing upon which roost features the individual tree species are most likely to hold, and both how quickly they will form and how long they will last. When considering the non-porous conifers, logic would suggest that both birds and mammals would find the presence of sticky resin with its intense odour, unpleasant and even potentially hazardous (think tacky resin on wings and fur). As a result, it might be concluded that a batroost would be unlikely to be present in a resinous conifer unless the stem or limb was entirely dead. However, the time an individual tree takes to decay is dependent upon the environmental conditions. Morris & Perring (1974) suggest that in dry, exposed conditions a conifer stem might persist for tens of years, whereas the same specimen in mild moist conditions would be expected to decay more rapidly. Finally, as we saw in Chapters A2 and A3, many rot-fungi specialise in either live or dead wood, but few attack both. As a result, a tree that has a sapwood shell surrounding the Heartwood core may need a severe attack by two or more fungi to really weaken it, whereas a sapwood tree which has little (if any) defence and only one sort of wood, might soon be overcome once infected by a parasitic fungus. The longevity of a roost tree may have some bearing upon which species colonise them. I can’t help but wonder whether pipistrelles are so often found in birch because they only use trees at a specific point in the year, and then need lots of them. As PRF in birch are constantly forming and collapsing maybe this suits them as the roosts are unlikely to be occupied by any other species? This will be a fascinating aspect of the data I hope this project will accrue in the longer term.

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Section A. TREES Chapter A10 – Trees – Association PRF __________________________________________________________________________________________

TREES - ASSOCIATION PRF GENERAL The Association Class has only two PRF forms; Unions (where two limbs or stems cross and become fused or entwined) and Ivy Hedera helix.

UNIONS General Unions comprise the typically ‘pocket-like’ PRF that form when two independent branches or stems cross, or a double-leader grows in such close parallel that the two independent stems fuse (a characteristic of beech Fagus sylvatica and Scots pine Pinus sylvestris).

Photo A10.1. A stem Union on an alder Alnus glutinosa in the RSPB Gwenffrwd Dinas reserve. Note the pad of bark extending out from the stem on the right and flaring out and round the stem on the left. Note also the lack of moss just below the pad… Suspicious? Very!

Formation When two independent limbs grow across one another in close proximity, as the annual rings increase their diameter the bark gradually flares out above, below and between the point of contact, and this creates a shallow pocket at the base of the unit, extending up to the point the limbs make contact. In theory the limbs should never ‘fuse’, but anyone who has seen the __________________________________________________________________________________________ A10 - 1

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phenomenon on beech will tell you this simply isn’t true and in fact fusing appears possible on a wide variety of species, including the ancient pedunculate oaks Quercus robur of Staverton Park and sessile oak Q. patraea stems in the Quantocks coppice-woods.

Photo A10.2. A Union on a Scots pine Pinus sylvestris in which the Scottish Leisler’s Project recorded an individual female Leisler’s bat Nyctalus leisleri. © Stuart Spray 2012

Photo A10.3. Close-up of Photo A10.1 Union. © Stuart Spray 2013 __________________________________________________________________________________________ A10 - 2

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Photo A10.4. Stem Union on sessile oak Quercus patraea.

Identification Unions are so distinctive they are unlikely to be mistaken for anything else.

Bat occupancy Table A10.1 on the following page lists the bat species known from detailed accounts and photographic evidence to make use of Unions as roost sites. __________________________________________________________________________________________ A10 - 3

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Table A10.1. The bat species known from detailed accounts and photographic evidence to make use of Unions as roost sites. BAT SPECIES Leisler’s bat Nyctalus leisleri

ROOST STATUS Transition (J. Haddow 2012 pers. comm., March)

IVY Hedera helix General For ivy to provide an environment suitable for occupation by roosting bats it has to have attained significant age. Typically the stems should be a minimum of 50 mm diameter (ideally some even larger) and have sections that have formed pockets into which bats sidle into or crawl up and under to rest against the bark of the mature tree (G Billington 2011, pers comm., September).

Formation As ivy grows upward; younger stems often pass over older ones, or intertwine for support. As the ivy gets older the stems expand and those beneath push the crossing stems away from the bark forming a network of small pockets under the newer growth (see Photo A10.5).

Photo A10.5. Large-diameter ivy Hedera helix with a multitude of pockets in which bats might hide. __________________________________________________________________________________________ A10 - 4

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In some cases the ivy stems fuse and form plates, pockets and crevices replicating conditions within a wide variety of other PRF (see Photo A10.6). In the vast percentage of cases these stems will lack foliage and will be easily inspected by working from the ground upward.

Photo A10.6. Fused ivy Hedera helix growth on an ash Fraxinus excelsior stem. Note the longitudinal entrances which open into numerous pockets and crevices. __________________________________________________________________________________________ A10 - 5

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Identification Ivy is a climbing (and occasionally carpeting) plant, familiar to everyone I hope, so it is improbable it would be misidentified.

Bat occupancy The use of ivy as a roost-feature was first brought to widespread attention of bat-workers by Dr Geoff Billington in his 2001 barbastelle Barbastella barbastellus study. In total Dr Billington and his team have recorded five ivy roosts, ranging in heights from approximately 4-18 m (Natural England 2012). All have only been occupied by individual bats and all were on either oak Quercus spp. or ash Fraxinus excelsior trees on the woodland edge. I have only encountered one species of bat using ivy. This was a colony of Daubenton’s bats Myotis daubentonii which made extensive use of ivy for night-resting (see Photo A10.7) I made a thorough search of the ivy in the morning to see what evidence they had left and drew a total blank; not a single dropping was found and no discernible smoothing was evident.

Photo A10.7. Ivy Hedera helix used for night-resting by Daubenton’s bats Myotis daubentonii.

Table A10.2 on the following page, lists the bat species known from detailed accounts and photographic evidence to make use of ivy as roost sites. __________________________________________________________________________________________ A10 - 6

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Table A10.2. The bat species known from detailed accounts and photographic evidence to make use of ivy as roost sites. BAT SPECIES Barbastelle Barbastella barbastellus Daubenton’s bat Myotis daubentonii

ROOST STATUS Transition & Hibernation (Billington 2004, Natural England 2012) Night-resting (H. Andrews pers. obs.)

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Section B. TREE-ROOSTING BATS Chapter B1 – Tree-roosting bats - A woodland bat species literature review __________________________________________________________________________________________

TREE-ROOSTING BATS – A WOODLAND BAT SPECIES LITERATURE REVIEW GENERAL In 1921 Edward Step suggested that for most people “…the bat is still a bat without distinction of species”. I would suggest that in 2012 the situation in relation to Phytophylous bats (the woodland or tree-roosting species) is little changed, and might in fact be worse as there is a general tendency to accept the hypothesis that the individual species have little distinction, and all behave entirely randomly. This is a self-perpetuating misconception of a classic kind; the suggestion is made that treeroosts are very rare and, as tree-roosting species appear to exhibit no particular behaviourpattern, the amateur naturalist is unlikely to find one. As a result few people look and so few roosts are found, and with only a small data-set to play with patterns aren’t readily defined. So our understanding is retarded by the acceptance of a discouraging comment that leaves all the hard work up to academics. It is an odd irony that, as the result of conservation focus resulting in a tendency for academic studies to focus upon the rarer species (quite rightly), we now know a good deal more about the tree-roosting ecology of the rare barbastelle Barbastella barbastellus and Bechstein’s bats Myotis bechsteinii than we do of common pipistrelle Pipistrellus pipistrellus and soprano pipistrelle Pipistrellus pygmaeus. However, returning to the subject in hand, the wit that first coined the phrase “bats don’t read books” bears a lot of the responsibility for the lack of impetus within the progression of our understanding of tree-roosting ecology. The suggestion inherent within this glib statement is that you can’t predict where individual species will roost but that is flawed; the problem is that the books are outdated, incomplete and, in some cases, just plain wrong. Bats may not read books, but that doesn’t mean that bats are inscrutible, or that we should ignore common sense and reason and search for the patterns that the rules of natural selection tell us must be there, or that having begun to understand the situation the books should not be written and rewritten regularly (an advantage of web-hosted documents). The following accounts represent all I could find for the principal tree-roosting species accepted as resident in the British Isles. While I’m confident I will not be challenged when I say greater horseshoe bats Rhinolophus ferrumequinum and grey long-eared bats Plecotus austriacus do not roost in trees, and serotine Eptesicus serotinus and lesser horseshoe bats Rhinolophus hipposideros do so only in exceptional circumstances, the reader may be somewhat surprised that the whiskered bat Myotis mystacinus does not have an individual account either. The reason for this is that I simply could not find sufficient evidence to __________________________________________________________________________________________ B1 - 1

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support historic suggestions that they roost in trees in anything but very exceptional circumstances. These species are therefore confined to a section of their own at the close of this Chapter, and may have yet to be joined by Brandt’s bat Myotis brandtii, for which evidence is thin but just enough to warrant inclusion in 2012. At present, due to the widely-held belief (perhaps borne of inconclusive ultrasound survey experiences) that common and soprano pipistrelles are primary tree-roosters, the pipistrelles open with a summary of historic accounts written long before they were recognised even as two, and latterly three, individual species, before they are treated to sections of their own. This may in fact do no more than demonstrate that the published evidence to support their use of tree-roosts is at present flimsy and despite (or perhaps because) of my own early ultrasound conclusions, I am unconvinced that they do not use trees as widely as perhaps we might want to believe, but may (particularly in the case of soprano pipistrelle) occupy them more in winter than they do in summer. History may yet pillory me for this, but I’m happy to take my chances. As a personal observation, the key frustration inherent to the following text is the vagary of many of the roost-feature descriptions, which do not define the myriad roost-features using recognised arboricultural terminology. However, this is in the vast majority of cases borne of the fact that arboriculture has come further than bat ecology in the last 20 years and a good deal of the terms are relatively new, rather than any failing on the part of the naturalist and academics upon whose work we now rely. Nonetheless, the terminology is now defined and there is therefore a good deal of remedial work to be done in order to define exactly how what sort of ‘hole’ Brandt’s bats roost in, or exactly what sort of crevices, splits and cracks so many other species are said to favour. Where I have found accounts with accompanying photographs that allowed the roost-feature to be identified using forestry nomenclature I have done so and these are shown with an accompanying * symbol. I hope this represents a reasonable baseline of what is known in 2012, but I would welcome a prompt if I’ve missed anything. Please do remember this isn’t a static text and will be updated annually so please do email me (henry.andrews@aecol.co.uk) if you hear of anything new. I’m not always as up to speed as I might like, and I’d rather hear of a new paper from a dozen different sources than not at all.

BARBASTELLE Barbastella barbastellus Barbastelle – General In the British Isles barbastelle forage over rough/unimproved grassland and gorse scrub (with heathland, hedgerows and streams also visited) in summer and woodlands (with up to half the time spent in conifer plantations) in winter (Natural England 2012). On the continent barbastelle also forage in gardens near forests, and along hedges (Dietz et al. 2011). __________________________________________________________________________________________ B1 - 2

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Barbastelle – Host-tree location Roost habitat - General In the British Isles barbastelle populations show a clear preference for large, unmanaged ancient/semi-natural woodland with a closed canopy and dense evergreen understorey, with abundant holly and ivy and lots of dead trees (Greenaway 2001, Forestry Commission for England & Wales et al. 2005, Natural England 2012). Wooded riverine habitat appears particularly favoured (Harris & Yalden 2008). Roost habitat - Spatial Host trees are typically located well within the woodland interior, >25 m from the woodland edge (Greenaway 2001).

Barbastelle – Host-tree dead/alive It has been suggested that dead and storm-damaged trees are favoured (Greenaway 2001, Altringham 2003), but this is not always true; in Horner Woods in Somerset the higher proportion of roost trees are alive (G. Billington 2012, pers comm., 8th November).

Barbastelle – Location of tree-roost feature on host-tree Stem/branch A preference for roosts on the stem has been noted (Vesey-Fitzgerald 1949, Schofield & Fitzsimmons 2004). Height In the British Isles barbastelles favour high roosts in the summer within a range of 10 m 16.7 m (Billington 2004). In contrast, hibernation roosts are much lower, with heights of less than 1 m recorded (Altringham 2003, Billington 2004). A breakdown of the heights and of 36 roosts recorded by Dr Geoff Billington in Somerset (Natural England 2012) is provided at Table B1.1 on the following page.

Barbastelle – Tree-roost seasonal occupancy In the British Isles the majority of barbastelle roosts are in trees which are used year round; __________________________________________________________________________________________ B1 - 3

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by maternity colonies, as transitory roost occupied by individuals and small groups, and also for hibernation (Altringham 2003, Boye & Dietz 2005). Table B1.1. Heights of 36 barbastelle Barbastella barbastellus roosts recorded by Dr Geoff Billington (Natural England 2012). FORM MATERNITY ( 7 roosts) TRANSITION (20 roosts) WINTER (8 roosts)

HEIGHT 2-6 m 2 (28.5%) 5 (25%) 3 (37.5%)

<2m Nil Nil 4 (50%)

>6m 5 (71.5%) 15 (75%) 1 (12.5%)

In summer colonies aggregate and an entire colony may roost in one woodland (Natural England 2012). In autumn and early winter however the colonies fragment; becoming less concentrated on a single wood, and may roost in smaller woodlands scattered throughout their summer foraging area (Natural England 2012).

Barbastelle – Preferred tree-roost feature General Barrett-Hamilton (1910) suggests the majority of early accounts of tree-roosts relate to bats discovered under the bark of trees. Step (1946) cites hollow trees. Burton (1968) again cites roosts behind loose bark. In the British Isles, small (10-20 females) nursery roosts have been recorded in tree holes and storm-cracks (Altringham 2003, Schofield & Mitchell-Jones 2003, Schofield & Fitzsimmons 2004), and vertical splits (Greenaway 2001). Maternity An extensive study in the south-west performed by Billington (2004, Natural England 2012) concluded that key maternity roost features comprised hazard-beams* and tear-outs*.

Transition/individuals Individuals have been recorded in rot-holes (Billington 2004), tree hollows (Greenaway 2001, Schofield & Fitzsimmons 2004), crevices (Vesey-Fitzgerald 1949), cracks (Altringham 2003), under bark (Altringham 2003, Natural England 2012), behind thick ivy (Natural England 2012), and in low-level frost-cracks (H. Andrews pers. obs. see Photos F & G). Hibernation Primary hibernation sites consist of horizontal splits (hazard-beams* or similar (see Photo’s __________________________________________________________________________________________ B1 - 4

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A to E)) and loose bark (particularly in dead, fallen but hung-up trees) with a small number also recorded in thick ivy at the base of the tree (Billington 2004, G. Billington 2011 pers. comm., September, Natural England 2012).

Photo B1.1. Low-level horizontal Hazard-beam occupied by an individual hibernating barbastelle Barbastella barbastellus (G. Billington 2011, pers. comm., September).

Photo B1.2. Fallen oak Quercus spp. under which Geoff Billington recorded an individual hibernating barbastelle Barbastella barbastellus (G. Billington 2011, pers. comm., September). __________________________________________________________________________________________ B1 - 5

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Photo B1.3. Close-up of the underside of the hung-up stem shown in Photo B1.2. Note the ivy Hedera helix and bark below in which the bat was roosting; remarkably like a Hazard-beam.

I think it is worth emphasising that in the most extensive study thus far carried out, 75% of the barbastelle roosts in split-type PRF were horizontal (Natural England 2012). In addition, barbastelles typically use more exposed roosts in the autumn/winter period than they do in summer. Massive hollow trees and or cracked trunks may also be occupied (Forestry Commission for England and Wales et al. 2005, Harris & Yalden 2008). Hibernation sites in trees have also been recorded on the Continent (Schober & Grimmberger 1987).

Barbastelle – Tree-roost switching A study in the British Isles found that breeding bats occupied roosts on average for 4 days (range 3-5) and fluctuations were noted in the number of bats present in maternity colonies which are divided among more than one tree-roost (Billington 2004).

Barbastelle – Tree-roost colony size Maternity colonies are small numbering less than thirty (Harris & Yalden 2008). Billington (2004) recorded a maximum nursery count of 26 females with 10 juveniles. Males are __________________________________________________________________________________________ B1 - 6

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solitary for much of the year and individuals of both sexes hibernate alone (Harris & Yalden 2008).

Photo B1.4. Another low-level barbastelle Barbastella barbastellus hibernation roost, this time in a massive limb recorded by Dr Geoff Billington.

Photo B1.5. Close-up of the entrance of the hibernation roosts shown in Photo B1.4. __________________________________________________________________________________________ B1 - 7

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Figure B1.1. Frost-crack in live sessile oak Quercus patraea stem in which the individual barbastelle Barbastella barbastellus on the right was recorded in April 2012. The bat was roosting 12 cm above the roost entrance which is 1.87 m above ground level.

Barbastelle – Cohabitation A Hazard-beam roost in Horner Woods, Devon, holds a barbastelle maternity roost in summer and hibernating noctules in winter. However, the species is not thought to regularly cohabit with other bat species. Barbastelle – Misc General Barrett-Hamilton (1910) suggests the species is timid and provides accounts of captive barbastelles being put-upon by brown long-eared bats in the same cage, even to the point of blood-letting! Commuting - reliance upon linear linkage No British data found. A radio-tracking study on the Continent (Kerth & Melber 2009) found that tagged bats crossed a motorway during nightly foraging, on occasion using underpasses

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but also flying directly across, which suggests they are not entirely reliant upon linear landscape elements. Barbastelle are said to be sedentary (rather than migratory) both in the British Isles and on the Continent (Hutterer et al. 2005).

BECHSTEIN’S BAT Myotis bechsteinii Bechstein’s bat – General Bechstein’s bats are very much woodland bats, requiring mature deciduous woodland with a well-developed three dimensional structure (Altringham 2003). They forage preferentially in deciduous woodland with water-bodies, and breeding females select closed-canopy woodland (Harris & Yalden 2008). Individuals will also hunt on tree-lines and hedgerows (Harris & Yalden 2008). On the continent they are also thought of as woodland bats, found in damp mixed woodland and pinewoods but also parks and gardens (Schober & Grimmberger 1987).

Bechstein’s bat – Host-tree Location Roost habitat - general In the British Isles tree-roosts are typically found in mature, closed canopy broadleaved woodland with a high level of ground cover (Flanders & Hill 2004). Breeding females preferentially select closed-canopy woodland in which to day-roost (Harris & Yalden 2008). Oak and ash are important roost trees and, in general, the species favours woodlands with small streams (Forestry Commission for England & Wales et al. 2005). Roost habitat - Spatial No British data found. On the Continent tree-roosts of Bechstein’s bats are found throughout woodland with no restrictions (Dietz et al. 2011, Hohti et al. 2011). A study in Luxembourg found that maternity colonies preferentially select trees without canopy connectivity between the host-tree and the tree in front of the roost entrance (Dietz & Pir 2011).

Bechstein’s bat – Host-tree dead/alive In the British Isles a significant preference has been demonstrated for live broadleaved trees (Flanders & Hill 2004), but it is also suggested that they favour old trees with dead branches (Altringham 2003). On the continent all 18 roosts found in one study were in live trees (Hohti __________________________________________________________________________________________ B1 - 9

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et al. 2011). In slight contrast, another study recorded seven roosts occupied by males in live trees, but eight of a total 57 (14%) maternity roosts in dead trees (Dietz & Pir 2011).

Bechstein’s bat – Location of tree-roost feature on host-tree Stem/branch No British data found. On the Continent 83% of roosts were recorded in the stem (15 of a total 18 roosts) has been noted (Hohti et al. 2011), and over 70% of maternity and male roosts (of a total 64) in a study in Luxembourg found in tree stems (Dietz & Pir 2011). Height Whilst it has been suggested that roosts are generally in the canopy (Altringham 2003), a focus study found no preference (Flanders & Hill 2004). It has been suggested the species may also be found very close to ground level (Forestry Commission for England & Wales et al. 2005). A study on the Continent (Dietz & Pir 2011) suggests that this disparity is due to contrasting preferences of males and females; 40% of maternity roosts between 5 – 10 m, 27% from 10 – 15 m, 27 % from 15 – 20 m and the last 6% above or below this range but, whilst males were recorded at great heights (>25 m) they were also recorded in frost-cracks below 2 m. Additional Continental studies and accounts have recorded roosts at heights of (0.5)1-5(18) m (Fuhrmann & Godmann 1991, Meschede & Heller 2000, Dietz et al. 2011).

Bechstein’s bat – Preferred tree-roost feature Primary In the British Isles green woodpecker Picus viridis holes and rot-holes are favoured for maternity roosts (Vesey-Fitzgerald 1949, Flanders & Hill 2004, Forestry Commission for England & Wales et al. 2005, Harris & Yalden 2008). No British information was found in relation to roosts of individual males or hibernation sites. On the Continent males have been recorded under bark (Červený & Bürger 1989), in tree holes (Schober & Grimmberger 1987) and stem crevices (Dietz et al. 2011). Dietz & Pir (2011) found 77% of maternity colonies in woodpecker-holes, and males in frost-cracks, knot-holes and tear-outs. Secondary Bechstein’s bats roost in cracks at the base of the tree (Forestry Commission for England and Wales et al. 2005) and behind loose bark (no height given) (Mackie & Racey undated). __________________________________________________________________________________________ B1 - 10

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Bechstein’s bat – Tree-roost seasonal occupancy In the British Isles tree-roosts are used year round by maternity colonies, individual males and for hibernation (Altringham 2003).

Bechstein’s bat – Tree-roost-switching No data on roost changes in the British Isles. On the Continent the maternity colonies of Bechstein’s bat change their roosts as often as nearly every day and visit the same roost site only two to three times in a year (Boye & Dietz 2005). Dietz & Pir (2011) found maternity colonies divided between two trees during pregnancy and lactation, but divided amongst three or more post-weaning. In addition, maternity colonies were transient between up to 50 roosts with duration of occupancy increasing during pregnancy; averages: pregnancy 1.5 days, lactation 3.3 days and post-lactation 4.8 days (Dietz & Pir 2011). Males however less transient averaging 6.6 days and this decreased over the course of the active year (ibid).

Bechstein’s bat – Tree-roost colony size Maternity colonies range from 20-130 bats divided into sub-groups of 3-80 bats (Harris & Yalden 2008). Autumn mating groups of up to five females to each male (op. cit.). On the Continent maternity colonies are typically smaller and comprise 10-50 (exceptionally up to 80) bats (Dietz et al. 2011). In their extensive study of the species in Luxembourg Check Dietz & Pir (2011) recorded maternity groups typically ranging from 17-70 bats, which were divided between two or three different roosts, whilst the males were for the most part solitary.

Bechstein’s bat – Cohabitation In eight years of regular visits to a group of bat-boxes occupied by colonies of Bechstein’s and Natterer’s bats Myotis nattereri, whilst the different species used the boxes on consecutive days, mixed occupancy was never recorded (Siemers & Swift 2006). On the continent the species prefers its own company but may be found with Natterer’s and Daubenton’s bats Myotis daubentonii (Dietz et al. 2011). This suggests that the species is not tolerant of other species and mixed roosts are uncommon.

Bechstein’s bat – Misc General On the Continent, Dietz & Pir (2011) noted significant differences in the internal __________________________________________________________________________________________ B1 - 11

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characteristics of tree-roosts occupied by maternity colonies and those occupied by individual males; maternity roosts are typically dome-shaped in the upper cavity apex, whilst solitary male roosts were cone-shaped. Commuting - reliance upon linear linkage Bechstein’s bats typically commute along hedges and treelines, but will cross open habitat upon occasion (Harris & Yalden 2008). A radio-tracking study on the continent found Bechstein’s bats would only cross a motorway via an underpass, suggesting they are reliant upon linear landscape elements as commuting routes (Kerth & Melber 2009). Bechstein’s bats are said to be sedentary (rather than migratory) both in the British Isles and on the Continent (Hutterer et al. 2005).

BRANDT’S BAT Myotis brandtii Brandt’s bat – General No British data found. On the Continent Brandt’s bat is thought of as a woodland bat, more often found in woodland than whiskered bat, and favouring woodland with water (Schober & Grimmberger 1987), foraging in both wet broadleaved woodland and coniferous woodlands (Taake K 1984, Ekman & De Jong 1996). The species may also be encountered on the woodland edge and in clearings (Dense & Rahmel 2002), and rows of trees and hedges may also be used (Dense & Rahmel 2002, Dietz et al. 2011). In Sweden the species was found to be negatively affected by habitat isolation (Ekman & De Jong 1996).

Brandt’s bat – Host-tree location Roost habitat - General No British data found. On the Continent Brandt’s bats favour old deciduous forests with particularly damp areas (Taake 1984, Boye & Dietz 2005) and it has been suggested that they are a species of woodland in its final decay phase (Sptizenberger 2001). Roost habitat - Spatial No British data found. On the Continent tree-roosts of Brandt’s bats are found throughout woodland with no restriction (Sptizenberger 2001, Dietz et al. 2011).

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Brandt’s bat – Host-tree dead/alive No British or Continental data found.

Brandt’s bat – Location of tree-roost feature on host-tree Stem/branch It has been suggested that British tree roosts are rare (Harris & Yalden 2008), but on the Continent they are said to favour roost sites on the stem (Strelkov 1983, Dietz et al. 2011). Height No British or Continental data found.

Brandt’s bat – Preferred tree-roost feature Primary No British data found. On the Continent maternity roosts have been recorded in large holes (Strelkov 1983), behind loose bark (Strelkov 1983, Dietz et al. 2011) and in cracks (Dietz et al. 2011). Secondary No British data found. On the Continent transition roosts have been recorded in large holes (Strelkov 1983), behind loose bark (Strelkov 1983, Dietz et al. 2011) and in cracks (Dietz et al. 2011).

Brandt’s bat – Tree-roost seasonal occupancy No British data found. On the Continent tree-roosts are used by maternity colonies and individual males (Dietz et al. 2011), but not for hibernation (Boye & Dietz 2005).

Brandt’s bat – Tree-roost switching No British data found. On the Continent Brandt’s bats are said to switch between neighbourhood tree-roosts frequently (Dense & Rahmel 2002). __________________________________________________________________________________________ B1 - 13

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Brandt’s bat – Tree-roost colony size No British or Continental tree-roost data found, but on the continent roosts found in batboxes typically comprise c. 20 bats (Dietz et al. 2011).

Brandt’s bat – Cohabitation No British or Continental tree-roosts accounts found.

Brandt’s bat – Misc General No further information. Commuting - reliance upon linear linkage No British data found. On the Continent Brandt’s bats are said to follow guiding linear landscape elements such as windbreaks and streams when flying through open habitat (Dietz et al. 2011). No seasonal migration studies have been performed in the British Isles and the species status; sedentary or migratory, is unknown (Hutterer et al. 2005). On the Continent Brandt’s bat is considered an occasional migrant but, partly due to identification problems before Brandt’s and whiskered bats were formally separated, the situation is still far from clear (Hutterer et al. 2005).

DAUBENTON’S BAT Myotis daubentonii Daubenton’s bat – General Daubenton’s bat is associated with still or slow-moving freshwater, in open countryside (Harris & Yalden 2008) and is dependent upon the presence of trees or woods for roosts (Vesey-Fitzgerald 1949). In the British Isles Daubenton’s bats rarely roost far from water (Barrett-Hamilton 1910, Altringham 2003) and the species favours situations where woodland grows close to the water’s edge (Barrett-Hamilton 1910). Vesey-Fitzgerald (1949) suggested that where there are trees in association with water Daubenton’s bats might even appear in the centre of cities. However, this was before the large-scale introduction of highpowered street-lighting; a more recent study in London (Mickleburgh 1987) found the species __________________________________________________________________________________________ B1 - 14

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limited to the margins of suburban areas. On the Continent individual Daubenton’s bats also hunt in parks and meadows with fruit trees (Dietz et al. 2011) and may also be found in cities (Gaisler et al. 1998), although this has been again shown to be more common in older outskirts rather than in city centres (Gaisler et al. 1998). Schober & Grimmberger (1987) suggest the species is primarily a woodland bat.

Daubenton’s bat – Host-tree location Roost habitat - General In the British Isles host trees are typically bankside trees (Altringham 2003), avoiding turbulent river sections (Warren et al. 2000), but may also be within woodland (Arnold et al. 1998). On the continent the species also roosts in urban areas (Dietz et al. 2011). Roost habitat - Spatial Maternity roosts typically within 100 m of water (Barrett-Hamilton 1910), but may be within woodland near fire-breaks, wide forest trails and the woodland edge (Arnold et al. 1998). On the continent trees within 200 m of water are favoured (Nyholm 1965), and roost studies in woodland found all within 74 m of the woodland edge (Boonman 2000), a significant number within 50 m of the woodland edge (Boonman 2000) and > 40% within 30 m of the woodland edge (Nagel & Häussler 2003).

Daubenton’s bat – Host-tree dead/alive No British data found. On the Continent live trees are favoured (Boonman 2000, Nagel & Häussler 2003, Dietz & Boye 2004, Boye & Dietz 2005). Daubenton’s bat – Location of tree-roost feature on host-tree Stem/branch No British data found. On the Continent they are said to favour roost sites on or near the stem (Boye & Dietz 2005). Height No mean average data British data found, however roosts have been recorded from 0.96 m (see Photo H) up to 4.8 m (H. Andrews, pers. obs.). On the Continent Schober & Grimmberger (1987) cite roosts of less than 1 m above the ground. Mean average heights of __________________________________________________________________________________________ B1 - 15

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1.4 m (Nyholm 1965) and 8.3 m (Boonman 2000) have been recorded for maternity colonies and 3.8 m within a range of 1 – 25 m (Meschede & Heller 2000, Rieger 1996) for roosts of individual males.

Photo B1.6. Tiny frost-crack at 0.96 m in sessile oak Quercus patraea frost-crack holding Daubenton’s bat Myotis daubentonii droppings (confirmed by DNA analysis).

Daubenton’s bat – Preferred tree-roost feature Primary Preferentially selects tree roosts with long, vertical splits including small crevices in branches as well as cavities in the main trunk (Racey et al. 1998). Also uses cavities and tree holes (Mackie 2002, Altringham 2003), and in particular woodpecker holes (Forestry Commission for England & Wales et al. 2005). On the continent maternity colonies show a preference for old woodpecker holes enlarged upwards by rotting, and natural cavities where a branch had broken off and the wood rotted upward into the stem (Boonman 2000, Nagel & Häussler 2003, Dietz & Boye 2004). This is demonstrated in the Scottish example in Photo B1.7 submitted by David Dowse. __________________________________________________________________________________________ B1 - 16

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Photo B1.7. Tear-out on downy birch Betula pubescens holding a Daubenton’s bat Myotis daubentonii roost. © David Dowse 2012.

Secondary In the British Isles splits may be used (Mackie & Racey undated), and a regularly used nightroost has also been observed in thick ivy (H. Andrews pers. obs.). On the Continent, individual males have also been recorded under bark (Cervený & Bürger 1989) and in trunk cracks (Dietz et al. 2011).

Daubenton’s bat – Tree-roost seasonal occupancy Barrett-Hamilton (1910) suggests the species “deserts tree-roosts in autumn”, which is supported by Vesey-Fitzgerald (1949) who states that, in the British Isles, trees are used both __________________________________________________________________________________________ B1 - 17

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by maternity colonies and individual males but not as hibernation sites. However, Dietz et al. (2011) suggest that on the Continent the species may hibernate in trees.

Daubenton’s bat – Tree-roost switching No British data found. One study on the Continent found individual male Daubenton’s bats and even whole nursery colonies switched roosts frequently and, whilst they used the same roost holes year on year, it was not necessarily with the same degree of favour or for the same purpose; i.e. a hole that was occupied by a breeding colony for several years was then exclusively occupied by a male colony, whilst another previously unoccupied hole became the most frequented shelter for all aggregations (Červený & Bürger 1989). Dietz et al. (2011) suggest summer roosts in tree holes are changed every 3-5 days.

Daubenton’s bat – Tree-roost colony size Barrett-Hamilton (1910) describes a roost holding five males but no other British Isles data was found. On the Continent nursery colonies may number 20-50 females, and all male roosts of up to c. 20 bats have also been recorded (Dietz et al. 2011).

Daubenton’s bat – Cohabitation Mixed roosts of Daubenton’s and Pipistrellus sp. bats (Barrett-Hamilton 1910) have been recorded as have communal roosts with noctules Nyctalus noctula (Forestry Commission for England & Wales et al. 2005).

Daubenton’s bat – Misc General Individual Daubenton’s bats are not smelly (Barrett-Hamilton 1910) and “its resorts have not the evil smell that such places frequently give off” (Step 1924). “…Roost habit is to congregate in hanging clusters, somewhat like swarm of bees, but where there are nooks or crannies in its retreat it wedges itself into them on a system which can only be based upon the utmost economy of space” (Barrett-Hamilton 1910). Schober & Grimmberger (1987) describe roost entrances on the Continent as being circular or slit-shaped. Daubenton’s bat colonies in Continental studies (Nyholm 1965, Egsbaek et al. 1971, Haensel 1973) exhibited strong fidelity to favoured roosts. __________________________________________________________________________________________ B1 - 18

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Commuting - reliance upon linear linkage No British data found. On the continent Daubenton’s bats follow traditional favoured flightpaths along ditches, water-courses, hedges, forest edges and forest trails (Helmer 1983, Dietz et al. 2011). Although Continental colonies move between summer and winter roosts, distances amount to a few kilometres only, and the species is generally accepted to be sedentary rather than migratory (Hutterer et al. 2005).

NATTERER’S BAT Myotis nattereri Natterer’s bat – General Natterer’s bats have been found in a wide range of ‘woodland’ habitats, including coniferous plantations (Altringham 2003, Mortimer 2005), and often in the vicinity of water (VeseyFitzgerald 1949). Favoured foraging grounds comprise semi-natural broadleaved woodland, tree-lined river corridor and improved grassland, whilst arable and coniferous plantation are avoided (Smith 2001), Natterer’s bats may also be found in parkland (Swift 1997). The species roost in both deciduous and coniferous trees (Forestry Commission for England and Wales et al. 2005) and maternity colonies have been recorded roosting in Corsican pine plantations in Scotland (Mortimer 2005) and southern England (H. Andrews pers. obs.: wooden bat-box). On the Continent the species is predominantly a woodland bat, found in forests and parks with areas of woodland and marsh (Schober & Grimmberger 1987).

Natterer’s bat – Host-tree location Roost habitat - General In the British Isles tree-roosts are generally found in broadleaved trees in woodland (Smith 2001, Smith & Racey 2005) but also on hedgerows and tree-lines (Smith 2001, Forestry Commission for England & Wales et al. 2005). However, a study in Scotland also found the species within Corsican pine Pinus nigra in mature, thinned plantation (Mortimer 2005). Roost habitat - Spatial One study in the British Isles found Natterer’s bats occupying roosts throughout woodland and on hedgerows and tree-lines (Smith 2001).

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Natterer’s bat – Host-tree dead/alive An individual study in the British Isles found 100 % of tree-roosts to be in live trees (Smith & Racey 2005). It has however been suggested that Natterer’s bats may be found in small rotting trees (Forestry Commission for England & Wales et al. 2005), although whether ‘rotting’ relates to dead trees or live trees with areas of compartmentalised rot is unclear.

Natterer’s bat – Location of tree-roost feature on host-tree Stem/branch A study in the British Isles found Natterer’s bat tree-roosts evenly distributed between stem and branch locations (Smith 2001). No Continental data found. Height A study in the British Isles recorded a median height of 6 m within a range of 1.8 – 10.5 m (Smith 2001). No Continental data found.

Figure B1.2. Frost-crack in sessile oak Quercus patraea holding an individual Natterer’s bat Myotis nattereri. The stem is 17 cm Diameter at Breast Height and the bat is roosting at 2.4 m. __________________________________________________________________________________________ B1 - 20

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Natterer’s bat – Preferred tree-roost feature Primary Two studies in the British Isles have recorded a clear preference by maternity colonies for natural hollows in unbroken stems or branches in broadleaved trees (Smith 2001, Smith & Racey 2005). A third study (in Scotland) recorded roosts in longitudinal-splits between codominant stems on Corsican pines (Mortimer 2005). Individuals have also been recorded in low-level frost-cracks (H. Andrews pers. obs.), as shown in Photos J & K. On the continent the species is a primary tree-rooster with colonies associated with tree-holes (Schober & Grimmberger 1987, Dietz et al. 2011).

Photo B1.8. Natterer’s bat Myotis nattereri roost in a Tear-out on a sliver birch Betula pendula. © David Dowse 2013. __________________________________________________________________________________________ B1 - 21

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Secondary Cavities in a split on the stem or branch and in cavities within stumps left by broken-off limbs (Smith 2001, Smith & Racey 2005).

Photo B1.9. Natterer’s bat Myotis nattereri roost in a probable frost-crack in a birch Betula spp. © David Dowse 2013. __________________________________________________________________________________________ B1 - 22

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Natterer’s bat – Tree-roost seasonal occupancy In the British Isles it has been suggested that they use tree cavities year-round, even for hibernation (Smith & Racey 2002). However, this is apparently not the case on the Continent (Boye & Dietz 2005, Dietz et al. 2011).

Natterer’s bat – Tree-roost switching Natterer’s bats return year on year to previously occupied roosts (Smith & Racey 2005). The species is categorised as having ‘low roost-fidelity’ (Lewis 1995). In the British Isles maternity colonies are divided amongst several trees when young were able to fly, and colonies changed roosts every three days (Smith 2001). A similar pattern is also exhibited on the Continent with roosts changed every 2-5 days (Dietz et al. 2011)

Natterer’s bat – Tree-roost colony size It has been suggested that in the British Isles maternity colonies number 25-200 bats (Harris & Yalden 2008), although it is unclear whether treble-figures have been found in both trees and buildings. On the Continent nursery colonies vary between 20-50 females and individual males have been found on their own and within maternity aggregations (Dietz et al. 2011). All male roosts are also known, numbering up to 25 bats (op. cit.).

Natterer’s bat – Cohabitation Roosts are shared with bats of its own and other species (Step 1946). However, in eight years of regular visits to a group of bat-boxes occupied by colonies of Bechstein’s and Natterer’s bats, whilst the different species used the boxes on consecutive days, mixed occupancy was never recorded (Siemers & Swift 2006). On the Continent it has been suggested that Natterer’s bats may share roosts with Daubenton’s bats (Schober & Grimmberger 1987).

Natterer’s bat – Misc General Barrett-Hamilton (1910) relates an observation of a captive Natterer’s bat; “when sleeping this bat did not always hang by its feet, but often lay prone on the floor of the cage”. This may suggest the species might, as barbastelle and brown long-eared bats Plecotus auritus, occupy horizontal features as well as vertical. __________________________________________________________________________________________ B1 - 23

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Commuting - reliance upon linear linkage Swift (1997) suggests that Natterer’s bats are reliant upon linear landscape elements and that this is a predator avoidance strategy. No British migration data found. Continental recovery data for banded individuals suggest that Natterer’s bat may be able to migrate over long distances, although whether they do so regularly is still uncertain (Hutterer et al. 2005).

LEISLER’S BAT Nyctalus leisleri Leisler’s bat – General In the British Isles Leisler’s bat Nyctalus leisleri is a woodland bat (Vesey-Fitzgerald 1949, Altringham 2003), foraging preferentially along woodland, scrub and pasture, with urban and arable areas avoided (Waters et al. 1999). An inhabitant of woods, where it frequents, often in large parties, the cavities of hollow trees (Barrett-Hamilton 1910). On the continent the species is also considered a woodland bat (Schober & Grimmberger 1987), but also makes some use of parks (Dietz et al. 2011).

Leisler’s bat – Host-tree location Habitat No British or Continental data found. Spatial No British or Continental data found.

Leisler’s bat – Host-tree dead/alive No British or Continental data found.

Leisler’s bat – Location of tree-roost feature on host-tree Stem/branch Stem (Barrett-Hamilton 1910). On the Continent roosts in the stem appear to be favoured (Ruczynski & Bogdanowicz 2005). __________________________________________________________________________________________ B1 - 24

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Height Barrett-Hamilton (1910) provides one account of an individual roost holding a maximum five bats (at least one female) at 2.3 m (7’), and cites another observation of Leisler’s bats in one colony deserting the communal summer roost in early September to occupy separate roosts higher in the same tree (Barrett-Hamilton 1910). Burton suggests that the species favours roosts high in decayed oaks (Burton 1968) and this is supported by two studies in Czechoslovakia which have reported a preference for high roosts; > 8 m (Červený & Bürger 1989), with an average height of 18.6 m in a range of 9.5 m - 26 m (Ruczyński & Bogdanowicz 2005).

Leisler’s bat – Preferred tree-roost feature Primary In the British Isles the suggestion is that maternity colonies do not use tree-cavities, but they are used by males and non-maternity aggregations (Harris & Yalden 2008). However, individual females and aggregations of between 7-33 bats, have been recorded in knot-holes, wounds (see Photo O), hazard-beams and branch-tears (see Photo’s P & Q) within Culzean Country Park, south Ayreshire, Scotland by John Haddow and Stuart Spray (J. Haddow 2012, pers. comm., find email). Furthermore, trees are certainly used as hibernacula in Ireland, where most have been recorded in splits, but rot-holes and exfoliating bark are also used (Harris & Yalden 2008). Oddly perhaps, although an individual Leisler’s bat has been recorded using a wooden bat-box in Highgate Wood, London, the species has not been found in tree-roosts, despite both Natterer’s bats and noctule being present (C. Blamey 2012, pers. comm., January). On the continent Leisler’s bats have also been recorded in knot-holes and overgrown lightning strikes (Dietz et al. 2011) and in contrast to the British Isles, tree-roosts are used by maternity colonies. A study in Czechoslovakia reported a preference for natural cavities (rather than woodpecker-holes) of a hollow character (although 23% of their roosts were in crevices), with more than one entrance (Ruczyński & Bogdanowicz 2005). Again, they’re known to hibernate in tree holes (Schober & Grimmberger 1987). Secondary No clear data was found for the British Isles, but on the continent secondary roost features include woodpecker holes, crevices and lightning-strikes (Beck & Schorcht 2005, Ruczyński & Bogdanowicz 2005).

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Photo B1.10. Leisler’s bat Nyctalus leisleri roost recorded by the Scottish Leisler’s Project in a Tear-out on a Scots pine Pinus sylvestris. © John Haddow 2013.

Photo B1.11. Another Leisler’s bat Nyctalus leisleri roost recorded by the Scottish Leisler’s Project in a branch-tear on a Scots pine Pinus sylvestris. © Stuart Spray 2013. __________________________________________________________________________________________ B1 - 26

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Leisler’s bat – Tree-roost seasonal occupancy In the British Isles Leisler’s bat uses tree-roosts year-round (Vesey-Fitzgerald 1949, Altringham 2003), and whilst maternity colonies are generally found in houses, they move to hibernate in trees in winter (Forestry Commission for England & Wales et al. 2005).

Photo B1.12. Leisler’s bat Nyctalus leisleri roost recorded by the Scottish Leisler’s Project in a wound on a beech Fagus sylvatica. © Stuart Spray 2013. __________________________________________________________________________________________ B1 - 27

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Leisler’s bat – Tree-roost switching Given to changing its roost frequently (Burton 1968), but a study in Czechoslovakia suggested that roost-switching is perhaps less common than in other tree-roosting species (Červený & Bürger 1989).

Leisler’s bat – Colony size Barrett-Hamilton (1910) suggested a typical size of four to five bats in summer but hibernating singly; “no two inhabit the same hole.” This is in contrast to the more recent work of the Scottish Leisler’s Project which has recorded up to 40 bats in the same roost feature (J. Haddow 2012 pers. comm., March). On the Continent tree-roosts may hold 20-50 females, and all male colonies of up to 12 bats are also cited (Dietz et al. 2011).

Leisler’s bat – Cohabitation Solitary during hibernation, but on the Continent roosts may be shared with Daubenton’s bats (Červený & Bürger 1989) and noctules (Bauer & Walter 1977, Schober & Grimmberger 1987, Ruczyński & Bogdanowicz 2005) have been recorded.

Leisler’s bat – Misc General The roosts of large parties of Leisler’s bats may be odorous, but this is less perceptible that that of noctules (Barrett-Hamilton 1910). Extreme darkness would not appear to be a necessity, and colonies have been discovered in full view from outside the roost, with one instance of a bat asleep in the sun at the roost edge (Barrett-Hamilton 1910), a suggestion borne out by the experiences of the Scottish Leisler’s Project which recorded a roost below the union of a branch/stem cross-over (see Photos R & S) on a Scots pine (J. Haddow 2012 pers. comm., March). Although found in colonies, individuals have often been found from the middle of May to the end of September (Barrett-Hamilton 1910). In Scotland the seven roosts thus far recorded had entrances ranging in width from 4.5-12 cm. On the Continent, Ruczyński & Bogdanowicz (2005) reported all 39 of the roosts they measured had an entrance less than 6 cm wide. Commuting - reliance upon linear linkage One British study (Waters et al. 1999) suggested that barriers to commuting routes, such as roads have little restriction upon foraging. Shiel et al. (1999) suggested that Leisler’s bats __________________________________________________________________________________________ B1 - 28

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reduce the risk of predation during commuting by rapid flight. On the Continent De Jong (1994) suggested that Leisler’s bat was a fast flier and commuted in straight lines without reliance upon linear landscape elements. Leisler’s bat may be vagrant or sedentary in the British Isles and north-western Europe, but on the wider Continent Leisler’s bat is migratory, with large seasonally prompted movements annually (Hutterer et al. 2005).

Figure B1.3. Leisler’s bat Nyctalus leisleri roost recorded by the Scottish Leisler’s Project in a branch Union on a Scots pine Pinus sylvestris. © John Haddow & Stuart Spray 2013.

NOCTULE Nyctalus noctula Noctule – General A woodland bat (Vesey-Fitzgerald 1949) which, in the British Isles, roosts almost exclusively in tree holes (Altringham 2003). Noctules forage over pasture next to woodland, and over woodland itself (Walsh et al. 2001). In addition, Barrett-Hamilton (1910) cites an account of noctules in Cheshire frequenting open glades in summer but foraging in water-meadows towards the middle of September.

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Photo B1.13. Noctule Nyctalus noctula maternity roost in a canker on an ash Fraxinus excelsior. The staining beneath is a symptom of the canker and not the bats urine. © Antony Croft 2013.

Noctule – Host-tree location Habitat In the British Isles roosts are known to occur in both woodland edge and more exposed locations such as large individual trees in gardens in suburban and rural locations (Andrews Pers. obs., Harris & Yalden 2008). On the Continent tree-roosts are most often found in broadleaved trees (although they do also occasionally use conifers) in deciduous woodlands and parks (Boonman 2000, Boye & Dietz 2005). It has been suggested (Dietz et al. 2011) that they will also roost in cities if they have sufficient trees. Spatial In woodland, noctules favour roost sites in exposed locations on the woodland edge, where the tree gets plenty of sun (Forestry Commission for England and Wales et al. 2005), but they may also be found in other exposed locations, such as in larger gardens within rural villages __________________________________________________________________________________________ B1 - 30

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(Pers. obs.). On the Continent noctules preferentially roost near forest edges (significant number within 69 m) or along roads (Boonman 2000).

Noctule – Host-tree dead/alive It has been suggested that in woodland noctule favour dead trees (Forestry Commission for England & Wales et al. 2005).

Noctule – Location of tree-roost feature on host-tree Stem/branch No British data found. One study in Czechoslovakia (Ruczyński & Bogdanowicz 2005) recorded a clear preference for stem locations (24 out of a total 28 roosts equating to 86%). Height No British data found. Schober & Grimmberger (1987) suggest a range from 1-20 m. Hibernating individuals have been recorded in roosts 1.2 m and 1.8 m above ground level, although the former was located on the side of a ravine (H. Andrews, pers. obs.). Continental mean heights between 7.2 m and 19.2 m have been recorded within ranges of 4.6 – 30 m above ground level (Stratmann 1978, Schmidt 1988, Kronwitter 1988, Boonman 2000, Ruczyński & Bogdanowicz 2005).

Noctule – Preferred tree-roost feature Primary It has been suggested that noctule favour woodpecker holes (which they may also share with Daubenton’s bats). On the Continent, Ruczyński & Bogdanowicz (2005) reported all 28 of the roosts they were able to measure in their study were in hollow ‘chamber-like’ cavities rather than crevices, and several studies have recorded a clear preference for woodpecker holes (Stratmann 1978, Heise 1985, Kronwitter 1988, Frank 1997, Boonman 2000, Kanuch 2005, Ruczyński & Bogdanowicz 2005). The species hibernates in groups in well-insulated tree-hollows (Schober & Grimmberger 1987, Harris & Yalden 2008), but also individually in far less well insulated frost-cracks (H. Andrews, pers. obs. see Photos T, U, V & W) Secondary Rot holes (Ruczyński & Bogdanowicz 2005). __________________________________________________________________________________________ B1 - 31

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Figure B1.4. Frost-crack in a dead sessile oak Quercus patraea coppice stem on a ravine side in which the individual noctule Nyctalus noctula on the right was recorded in hibernation torpor 1.2 m from ground-level.

Figure B1.5. Frost-crack in a dead sessile oak Quercus patraea coppice stem in a ravine base in which the individual noctule Nyctalus notula on the right was recorded in hibernation torpor 1.8 m from ground-level.

Noctule – Tree-roost seasonal occupancy In England Barrett-Hamilton (1910) suggested that “it seems to be almost a rule with [noctules] to seek good winter quarters amongst houses or ruins” but in spring “forsakes them for an entirely arboreal life”. I have found three noctules in hibernation torpor in a treeroost in Devon, and a further two individuals hibernating in trees in a Somerset Woodland that they have never used in summer. I concluded the latter two roosts were only available to them when the foliage was down. On the Continent hibernation roosts are again in both trees and buildings (Dietz et al. 2011). __________________________________________________________________________________________ B1 - 32

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Noctule – Tree-roost switching A study in Czechoslovakia (Červený & Bürger 1989) found that roost-switching is a much less regular occurrence than with Bechstein’s and Daubenton’s bats, with the species exhibiting an affinity for particular holes within the territory, for example one hole was occupied almost exclusively by males, whereas another two holes were only occupied by maternity or breeding aggregations.

Noctule – Tree-roost colony size Dwells gregariously in large companies, in holes of trees where its presence is often betrayed by the excrement which may lie so thick as to darken the ground beneath the roost (BarrettHamilton 1910). There is a surprising lack of published British data available. This may reflect my competence as a researcher more than real dearth, or it may reflect the tendency for the more common species to escape attention. However, I have seen a tree in Devon from which a maximum 69 bats have been counted (George Bemment 2010, pers comm., May), and have myself counted three bats in hibernation torpor in the same tree. In addition, Harris & Yalden (2008) makes a passing reference to 73 bats in one roost and suggest that whilst European roosts may exceptionally number over 100 bats, such a figure is rare in the British Isles. The suggestion is also made that the same maternity colony may occupy several roosts at the same time (op. cit.) In the mating season males occupy so-called ‘lekking-roosts’ from which to ‘sing’ and by so doing attract a harem of females. No British data was found but on the Continent such harems may number up to 18 females (Harris & Yalden 2008).

Noctule – Cohabitation No British data found. On the Continent shared roosts with Daubenton’s bats (Červený & Bürger 1989) and Leisler’s bats (Bauer & Walter 1977, Ruczyński & Bogdanowicz 2005).

Noctule - Misc General Noctules are exceptionally fearless (Barrett-Hamilton 1910), and the males defend mating roosts in successive years both here and abroad (Harris & Yalden 2008). I have myself had a noctule descend from its roosting position in a lek to confront me at the roost entrance, and it didn’t back-off from shouting at me or my endoscope until I had retreated. __________________________________________________________________________________________ B1 - 33

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It has been suggested that on the Continent beech trees are often used but coniferous trees only very rarely (Dietz et al. 2011). In addition, and also on the Continent, Ruczyński & Bogdanowicz (2005) reported that although the inside cross-section of roosts occupied by noctules in their studies were significantly larger, the cavities themselves were shallower (vertically smaller) than those occupied by Leisler’s bats. Furthermore, Ruczyński & Bogdanowicz (2005) also reported all 28 of the roosts they were able to measure in their study had an entrance a maximum of 8 cm wide but more often (93% of the 28 roosts) under 5 cm. Finally, (back in the British Isles again) Barrett-Hamilton (1910) suggests that large colonies of noctules have an offensive smell. I have climbed a tree littered with noctule droppings and could only detect an odour within 0.3 m from the entrance, though it was a still day and I was trying, but that was just one roost and I would like to test this further. It has also been suggested that roosts may be identified by shrill vocalisations at dusk, dark streaks of faeces and urine below the entrance hole and, when occupied, by insects swarming around the entrance (Harris & Yalden 2008). The vocalisations are true of Daubenton’s bats too. But I would highlight that dark streaks may not be urine at all, and that such streaks are in fact far more common to tree-features that have never been occupied by roosting bats of any species. In addition, a good many dank rot-holes are occupied by invertebrates, and in particular, mosquitoes. Commuting - reliance upon linear linkage One British noctule radio-tracking study (Mackie & Racey 2007) reported that the bats flew fast and straight directly to foraging grounds, without appearing to follow linear landscape elements. Despite isolated records from the Orkneys and North Sea oilrigs, the British populations are considered sedentary, whilst on the Continent the noctule is migratory (Hutterer et al. 2005).

PIPISTRELLUS SPP. The division of common and soprano pipistrelle (or 45 and 55 pipistrelle as they are also known) was formally made (following the work of a number of other naturalists) by Jones & Barratt in 1999. In addition, the recognition of Nathusius’ pipistrelle Pipistrellus nathusii in England was only identified by Dr. Bob Stebbings in 1969, and the distribution of the species is still being defined as I type. I have therefore consolidated all the accounts of ‘pipistrelle’ made in the British Isles before 1999 into this opening section as they may be attributable to any one, or all, of the three species.

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Barrett-Hamilton (1910) Barrett-Hamilton relates an account of “retreats of half a dozen Pipistrelle sp., all roosting singly, in the stems of trees” and also comments that “It has been asserted that trees are much less frequented by this species [Pipistrellus sp.] than by some others, but, apart from Mr Moffat’s experience, instances are known of its having been discovered hiding behind loose bark and amongst ivy” (Barrett-Hamilton 1910). Interestingly, he makes the observation that, “unlike Daubenton’s bats which exit roosts by crawling to the mouth and then flying straight out, pipistrelles come right to the entrance of the roost and at the last moment drop, falling into flight.” This is something I’ve witnessed myself, where Daubenton’s will exit low roosts and fly on a level plane across the woodland floor, whereas pipistrelles drop from house roosts losing c. 1 m before they level out (think about it; have you ever found them lower than a ground-floor roof?), suggesting they wouldn’t ordinarily roost below c. 2 m. Step (1946) Observed that “any regular dormitory acquires a very fetid odour…”, but made no reference to pipistrelles roosting in trees. Vesey-Fitzgerald (1949) The pipistrelle hibernates in trees. Burton (1968) Cites a range a wide range of structural roost sites “…as well as in hollow trees.” Altringham (1999) Gave an account of solitary male pipistrelles roosting under the bark of trees in Britain, and at one location several were found (singly) under the thick bark of imported North American giant sequoias Sequoiadendron giganteum. Altringham (2003) Tree nursery roosts of pipistrelles are now uncommon.

NATHUSIUS’ PIPISTRELLE Pipistrellus nathusii Nathusius’ pipistrelle – General A lowland woodland bat (Altringham 2003) with a preference for roosts near large lakes (Harris & Yalden 2008). Nathusius’ pipistrelle favours riparian foraging habitats, __________________________________________________________________________________________ B1 - 35

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broadleaved and mixed woodland and parkland (Harris & Yalden 2008). It is also occasionally found in farmland (Harris & Yalden 2008) including large hedgerows in tillage (H. Andrews, pers. obs.), but nearly always near water. Schober & Grimmberger (1987) suggest that Nathusius’ pipistrelle is a typical representative of the woodland bat group, found in both damp deciduous wood and dry forests. On the continent, in addition to those habitats already listed, the species forages along rides, paths and woodland edges (Schober & Grimmberger 1987), and parkland near water is also visited (Dietz et al. 2011).

Nathusius’ pipistrelle – Host-tree location Habitat No British data found. On the Continent tree-roosts may be found in deciduous, pine and wet woodland, and parkland, near the forest edge and close to open water (Boye & Dietz 2005). Spatial No British data found. On the Continent sunny woodland edges near forest roads and clearings are favoured for maternity sites (Schorcht et al. 2002), whilst individual males have also been recorded in trees in exposed places, such as tree avenues (Dietz et al. 2011).

Nathusius’ pipistrelle – Host-tree dead/alive No British or Continental data found.

Nathusius’ pipistrelle – Location of tree-roost feature on host-tree Stem/branch No British or Continental data found. Height No British or Continental data found.

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Nathusius’ pipistrelle – Preferred tree-roost feature Primary The only information regarding favoured features of Nathusius’ pipistrelle tree-roosts in the British Isles relates to references of tree hollows used as mating roosts (Harris & Yalden 2008) and hollow trees utilised for hibernation (Altringham 2003). On the Continent, maternity colonies of the species have been recorded occupying tree-holes and bark crevices (Boye & Dietz 2005, Dietz et al. 2011), hollow trees and cracks in trees (Schober & Grimmberger 1987). Overall, the species is said to prefer cracks in which to roost but hibernates in hollow trees (Schober & Grimmberger 1987). Secondary On the Continent roost features occupied by individual bats include tree holes (Schober & Grimmberger 1997, Dietz et al. 2011) and crevices (Vierhaus 2004).

Nathusius’ pipistrelle – Tree-roost seasonal occupancy No British data found. On the Continent the species is said to occupy trees year round (Boye & Dietz 2005).

Nathusius’ pipistrelle – Tree-roost switching No British or Continental data found.

Nathusius’ pipistrelle – Tree-roost colony size No British or Continental data found.

Nathusius’ pipistrelle – Cohabitation No British or Continental tree-roosts accounts found.

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Nathusius’ pipistrelle – Misc General Nothing of note. Commuting - reliance upon linear linkage No British migration data found. On the Continent Nathusius’ pipistrelle is a long-distance migratory species (Hutterer et al. 2005).

COMMON PIPISTRELLE Pipistrellus pipistrellus Common pipistrelle – General Common pipistrelle roosts are usually found in human habitations (Harris & Yalden 2008) with tree roosts rarely recorded. In the British Isles common pipistrelles hunt in woodland (including coniferous and mixed plantation), over rivers and lakes, unimproved grassland, and improved cattle pasture (Davidson-Watts & Jones 2006). On the continent common pipistrelles are also found in city-centres and rural settlements (Dietz et al. 2011).

Common pipistrelle – Host-tree location Habitat No British or Continental data found. Spatial No British or Continental data found.

Common pipistrelle – Host-tree dead/alive No British or Continental data found.

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Common pipistrelle – Location of tree-roost feature on host-tree Stem/branch No British or Continental data found. Height No British or Continental data found.

Common pipistrelle – Preferred tree-roost feature Primary Under loose bark (Altringham 1999, Dietz et al. 2011) and crevices (Schofield & MitchellJones 2003). Tear-out on birch (see Figure B1.6) leading into rot-column (D. Dowse 2012, pers. comm., January). Secondary No British or Continental data found.

Figure B1.6. Branch-tear on downy birch Betula pubescens in Scotland holding an individual common pipistrelle Pipistrellus pipistrellus. © David Dowse 2012. __________________________________________________________________________________________ B1 - 39

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Common pipistrelle – Tree-roost seasonal occupancy No British or Continental data found.

Common pipistrelle – Tree-roost switching No British or Continental data found.

Common pipistrelle – Tree-roost colony size No British or Continental data found.

Common pipistrelle – Cohabitation No British or Continental tree-roosts accounts found.

Common pipistrelle – Misc General Nothing of note. Commuting - reliance upon linear linkage Pipistrelles in a study in the Netherlands were observed almost entirely close to landscape elements (Verboom & Huitema 1997). Furthermore, Verboom & Spoelstra (1999) identified the importance of sheltered wind-free foraging sites, and demonstrated that parallel tree-lines were more important for commuting than single hedges. I performed a survey of a little woodland on the edge of an airfield just outside Lincoln several years ago. In the early evening I was able to watch (using binoculars) a succession of over a dozen common pipistrelles Pipistrellus pipistrellus fly enter the site up the woodland edge and navigate around the perimeter of the airfield along a hedge. Later in the evening when it was fully dark, lights came on over a roundabout c. 0.5 km across the airfield and the pipistrelles switched their flight-path to fly directly across the airfield heading for the roundabout and I could still see them with the binoculars. When I looked into it there was a large pond just beyond the roundabout on the far side of the road, and it was teeming with pipistrelles. This pattern happened over all three survey visits and comprised a minimum five bats on the third night. This suggests predator avoidance to me… __________________________________________________________________________________________ B1 - 40

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Regular roost changes of up to 34 km within a maximum 69 km in England (Thompson 1992). On the Continent the species is thought to be mostly sedentary rather than migratory (Hutterer et al. 2005).

SOPRANO PIPISTRELLE Pipistrellus pygmaeus Soprano pipistrelle – General Soprano pipistrelle roosts area typically found in areas of human habitation (Harris & Yalden 2008). The species forages among riparian woodland, riparian trees and parkland (Racey & Swift 1985).

Soprano pipistrelle – Host-tree location Habitat No information was found to clarify what purpose to soprano pipistrelle (maternity, individual male, hibernation) tree-roosts serve in the British Isles, or in which habitats treeroosts are typically located. However, a Scottish study of building roosts (Jenkins et al. 1998) found that whilst soprano pipistrelles did not select roosts with specific physical attributes, they did show a marked preference for roosts in close proximity to specific habitat features; less than 50 m from mature trees, hedges, woodland-edge etc., and less than 500 m from the nearest river. They were also significantly close to woodland blocks of greater than 1 ha surface area. On the Continent the species appears to favour wet deciduous forests and forests along rivers (Boye & Dietz 2005). Spatial No British or Continental data found.

Soprano pipistrelle – Host-tree dead/alive No British or Continental data found.

Soprano pipistrelle – Location of tree-roost feature on host-tree Stem/branch No British or Continental data found. __________________________________________________________________________________________ B1 - 41

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Height No British or Continental data found.

Soprano pipistrelle – Preferred tree-roost feature Primary In the British Isles, soprano pipistrelles have been recorded roosting in tree-holes (Park et al. 1996, Howe 1997) and branch-tears (D. Dowse 2012, pers. comm., January), as demonstrated by none other than Mr Dowse himself at Photo B1.14. Secondary Under bark (Altringham 1999), in splits (Mackie & Racey undated) and in crevices (Schofield & Mitchell-Jones 2003).

Photo B1.14. David Dowse proves the point: soprano pipistrelles Pipistrellus pygmaeus definitely do roost in pedunculate oak Quercus robur trees! © David Dowse 2012. __________________________________________________________________________________________ B1 - 42

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Soprano pipistrelle – Tree-roost seasonal occupancy No British or Continental data found. Soprano pipistrelle – Tree-roost switching No British or Continental data found.

Soprano pipistrelle – Tree-roost colony size No British or Continental data found.

Soprano pipistrelle – Cohabitation No British or Continental tree-roosts accounts found.

Soprano pipistrelle – Misc General Nothing of note. Commuting - reliance upon linear linkage No seasonal migration studies have yet been performed in either the British Isles or on the Continent, and the species status; sedentary or migratory, is still unknown (Hutterer et al. 2005).

BROWN LONG-EARED BAT Plecotus auritus Brown long-eared bat – General Whilst it has been suggested that brown long-eared bats use trees as nursery roosts (Altringham 2003), tree holes are more often used as transitory roosts, which are used in connection with mating behaviour (Swift 1998). A study in Scotland found that tree holes were used only as temporary roosts, and only rarely by maternity colonies (Entwistle 1994). Brown long-eared bats preferentially forage in light deciduous woodland (Harris & Yalden 2008), with deciduous woodland favoured over coniferous (Entwistle et al. 1996), but move __________________________________________________________________________________________ B1 - 43

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out onto hedgerows in the autumn (Murphy et al. 2012). On the continent brown long-eared bats also forage around individual trees in parks and gardens (Dietz et al. 2011).

Brown long-eared bat – Host-tree location Habitat Roosts in open woodland in river valleys are favoured (Entwistle et al. 1997, Altringham 2003). Spatial Brown long-eared bats may occupy roosts in cluttered conditions such as those surrounded by moderately dense understorey vegetation. An individual study found the median distance of roosts outside woodland and broadleaved woodland in the locality was only 60 m (Entwistle et al. 1997).

Brown long-eared bat – Host-tree dead/alive No British of continental data found.

Brown long-eared bat – Location of tree-roost feature on host-tree Stem/branch No British of continental data found. Height Roosts in trees may be close the ground (Forestry Commission for England & Wales et al. 2005), particularly those occupied by individuals. I myself have found four roosts below 1 m including a maternity roost with an entrance at 0.9 m above ground-level, a hibernation roost with the entrance at 0.99 m (see Photo B1.15), and five at 1-2 m (H. Andrews, pers. obs.). But roosts can also be much higher; an individual male has been recorded roosting in a hollow limb at 17 m (H. Andrews pers obs.). On the Continent most roosts are in the lower trunk (Fuhrmann & Godmann 1991), but range from as little as 30 cm above the ground (Boye & Dietz 2005) to the canopy (Fuhrmann & Godmann 1994).

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Figure B.1.7. Brown long-eared bat Plecotus auritus maternity roost in a sessile oak Quercus patraea Frost-crack with an entrance only 0.99 m from ground-level. Note the damp interior of the roost which is bobbly rather than smooth but clean, firm and damp, and unoccupied in any other season.

Brown long-eared bat – Preferred tree-roost feature Primary In the British Isles tree cavities (Swift 1998) are occupied in summer, but also for hibernation (Altringham 2003, H. Andrews pers. obs.). Suitable cavities include rot holes where branches have been lost, hazard-beams, and on-going investigations by the author have thus far recorded thirteen roosts in low-level frost-cracks, which are also used for hibernation. On the Continent the species favours tree holes (Schober & Grimmberger 1987), and maternity colonies have been recorded in rot-holes, woodpecker holes, crevices and behind loose bark (Meschede & Heller 2000). The entrance of roosts may be obscured by branches or vegetation (Fuhrmann & Seitz 1992, Leitl 1995). Hibernation sites holding individual bats been recorded in hollow trees (Step 1946), including low-level frost-cracks (H. Andrews pers. obs.). On the Continent hibernation sites in trees have been found (Schober & Grimmberger 1987). Secondary On the Continent individuals have been found in wood crevices and behind loose bark (Boye & Dietz 2005). __________________________________________________________________________________________ B1 - 45

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Figure B1.7. Tom Staton indicates the presence of three brown long-eared bats Plecotus auritus in this partially healed Frost-crack in a sessile oak Quercus patraea stem. The bats were given away by the tragus of an individual in the top entrance. If you look at the sequence on the left you can see a white spot showing up in the top of the entrance on the middle slide, look below and you’ll see a close-up. All the bats were torpid, and my 9 mm endoscope was too wide to inspect the feature!

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Brown long-eared bat – Tree-roost seasonal occupancy Year round occupancy (H. Andrews, pers. obs.).

Brown long-eared bat – Tree-roost switching Both maternity colonies and individual males appear moderately nomadic (H. Andrews, pers. obs.), but the species has shown to exhibit high roost-fidelity between years (Harris & Yalden 2008). On the continent the maternity colonies of brown long-eared bat change their roosts every second to fourth day (Heise & Schmidt 1988, Fuhrmann 1991, Fuhrmann & Seitz 1992).

Brown long-eared bat – Tree-roost colony size In the British Isles maternity colonies are generally small; 15-20 bats (Harris & Yalden 2008), 10-12 bats (H. Andrews pers. obs.). On the continent far larger sizes occur with Dietz et al. (2011) citing aggregations of 5-50 females, while the males remain solitary.

Brown long-eared bat – Cohabitation No British tree-roosts accounts found. On the Continent it may occur in mixed roosts with other species (Schober & Grimmberger 1987).

Brown long-eared bat – Misc General Barrett-Hamilton (1910) cites Messrs, Alcock and Moffat who found that the tree most frequently selected by brown long-eared bats in which to forage was the ash, amongst the branches of which it was seen every evening from May to September. Barrett-Hamilton (1910) also relates an observation of an individual hibernating within a hole located at 2 m height on a beech tree, and cites Mr Charles Oldham who suggests that solitary hibernation is the almost invariable rule. Commuting - reliance upon linear linkage High reliance upon linear landscape elements, with tree-lines, hedges, overgrown banks and other sheltering linear cover used for commuting (Entwistle et al. 1996). __________________________________________________________________________________________ B1 - 47

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Sedentary (rather than migratory) both in the British Isles and on the Continent (Hutterer et al. 2005).

MISCELLANEOUS ACCOUNTS OF EXCEPTIONAL TREEROOST USE Serotine Eptesicus serotinus Burton (1968) suggests that serotine hibernate in hollow trees or under loose bark on old or dead trees.

Whiskered bat Myotis mystacinus Barrett-Hamilton (1910) cites the whiskered bat as primarily a house-rooster but suggests that “less frequently it resorts to some convenient hole or crevice in a tree, or creeps behind a loose piece of bark.” Step (1946) cites the whiskered bat as being opportunistic and includes hollow trees and loose bark in its overall palette of roost sites. When his book was updated over twenty years later by Burton (1968), this account was little altered and the assertion that whiskered bats roosted in hollow trees and under loose bark was retained. This is supported by the suggestion that the species is “more a house-dwelling bat than a woodland bat” (Schober & Grimmberger 1987).

Lesser horseshoe bat Rhinolophus hipposideros Burton (1968) cites instances of summer roosts in hollow trees.

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TREE-ROOSTING BATS - COMPETITORS & PREDATORS GENERAL As well as bats, a multitude of invertebrates, 30 species of birds, common dormice Muscardinus avellanarius, woodmice Apodemus sylvaticus, yellow-neck mice Apodemus flavicollis, red squirrels Sciurus vulgaris, grey squirrels Sciurus carolinensis and pine martens Martes martes nest roost in Potential Roost Features. As a result, competition for PRF can be intense (Greenaway 2001). Some species co-exist with bats, some compete with bats, and some may also eat bats. This chapter provides a brief summary of the other organisms that may be encountered by the bat enthusiast in the search for tree-roosts.

INVERTEBRATES Bees The hive bee Apis mellifera occupies hollow trees (Imms 1947). The colonies are perennial (Imms 1947) and will remain within a tree cavity until the colony collapses (Dr Peter Kirby pers. comm.).

Figure B2.1. This Double-leader is in an ash Fraxinus excelsior in Chalkney Woods and holds a colony of hive bees Apis mellifera. __________________________________________________________________________________________ B2 - 1

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The population of a strong hive may number 50,000 to 80,000 (Imms 1947) and as the queen lives from four to five years the colony may prevent bats occupying a favoured PRF for some considerable time (AA 1973). Furthermore, a colony may outlive its queen if a new queen takes over (typically by killing the old one) (AA 1973).

Figure B2.2. Top left: Tree wasps Vespula sylvestris nest in Butt-rot. Top right: Hornets’ Vespa crabro nest in a Knot-hole. Bottom: Hive bees Apis mellifera nest in a woodpecker-hole.

Wasps The woodland wasp encountered in holes is the tree-wasp Vespula sylvestris (Imms 1947). Only the queen wasp hibernates. Tree-wasp colonies are therefore annual, lasting from late spring, until autumn.

Hornets The hornet Vespa crabro typically nests in hollow trees, but is rare and more often found in __________________________________________________________________________________________ B2 - 2

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southern England (Imms 1947, AA 1973). Only the queen hornet hibernates. Hornet colonies are therefore annual, lasting from late spring, until autumn.

Spiders Bristowe in his New Naturalist The World of Spiders (1971) cites a legend of a hero who evades capture by an enemy as a result of a spider building her web across the mouth of the cave in which he was hiding; the pursuer assuming that the web indicated that no one had passed that way. He also gives an account of a situation where the police failed to break down a door behind which a murderer was hiding, because they assumed the presence of spider’s web in the key-hole indicated that the lock had not been used for a very long time. Spiders either actively hunt, or trap by building orb (intricate, round, spoked and pretty) or sheet (irritating walk-into in the shed fumbling for the light-switch) webs. The webs of some species, such as Ciniflo fenestralis and Araneus gibbosus, are indeed adhesive when fresh (Bristowe 1971) and might be irritating to bats, but they don’t all make webs during the day (i.e. C. fenestralis which only hunts at night). Furthermore, other spiders, such as Segestria senoculata, Ballus depressus and Marpissa muscosa, live in silk tubes or cells under bark. The billowing sheet-webs of the Tegenaria; these ‘webs’ are not sticky at all. Please don’t be put off by thin layers or strands of web over a PRF entrance; it’s perfectly possible that the spider made the web after the bats had returned to rest (see Figure B2.3). Furthermore, whilst cotton-wool like clumps of webbing stuffing a crevice may suggest that the PRF in question had not been colonised by roosting bats, looser aggregations in a PRF with all other physical cues of historic occupation (right internal dimensions, smoothing of internal surfaces, lack of debris in the web etc.) may simply mean that the PRF is used seasonally. For example, PRF used as lekking-roosts may only be occupied for six weeks each autumn and hibernation roosts only occupied from December through February, a welltimed visit, might well result in a very different outcome (see Figure B2.4). I find it hard to imagine a situation where bats would abandon a historically occupied roost because spiders had moved in. It certainly doesn’t dissuade them from re-occupying hibernation roosts, bat-boxes or barge-boards on houses (pers obs.). Personal experience suggests to me that the presence of spider’s webs can only demonstrate that bats have not been present within a given period (i.e. that season). Furthermore, Bristowe (1971) suggest that many spiders commonly found on trees hibernate, and although young of that summer hatch in August or September, they wait in the maternity nest/cell/tube until the following spring before emerging. This would suggest that webs would be at a minimum in the winter period and thus less likely to be even an irritation to bats during the hibernation season. Let us not also forget that both Natterer’s bats Myotis nattereri and brown long-eared bats Plecotus auritus eat spiders (Schober & Grimmberger 1987, Dietz et al. 2011). I find it very __________________________________________________________________________________________ B2 - 3

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hard to believe that upon encountering a spider in a favoured roost a bat of any species wouldn’t simply eat it (Barrett-Hamilton (1910) says that "horseshoes probably snatch irregular meals on the cave-haunting moths and spiders which share their winter quarters").

Figure B2.3. Old spider-webs across the entrance of a noctule Nyctalus noctula roost, and the bat in residence in the apex (The two photos taken 30 seconds apart).

Figure B2.4. Left: Noctule Nyctalus noctula hibernation roost. Right: the same roost the following August (both photos taken from the same position using a Ridgid C300). __________________________________________________________________________________________ B2 - 4

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Diptera The Diptera are the true flies and many live in tree holes. Some hoverflies (Syrphidae) hibernate in them; others remain active all winter in humid hollows. In addition, arboreal species of mosquitos such as Anopheles plumbeus and Aedes geniculatus are well known occupiers of rot-holes, as are other Diptera (Morris & Perring 1974). Save for the occurrence of hibernating hoverflies, aggregations of flies are generally confined to damp/wet rot and knot-holes and (as with spiders), I can’t help thinking that any bat that found a fly in a PRF would just think itself lucky to have found a tasty morsel upon returning from a nights activity. It has been suggested that aggregations of buzzing flies are associated with roosting bats. Although aggregations of buzzing flies are associated with large aggregations of bat droppings, my experience is that they are more often associated with squirrel dens, abandoned birds-nests with dead fledglings and/or smashed eggs, and just mucky damp wetrot. The presence of an aggregation of flies around a PRF cannot therefore be used as an indicator; I’m afraid you’re still going to have to get up there and look inside.

Earwigs Dr. Jackie Underhill emailed me to say that she had found an individual torpid bat sharing an artificial roost-box with literally hundreds of earwigs (Dermaptera, J. Underhill 2012 pers. comm., February). Unfortunately, save from the fact that they don’t eat wood, I have been unable to find anything useful in terms of earwig ecology (can anyone recommend me a text?). I have yet to encounter a single earwig in a PRF in a tree, although I too regularly encounter them in wooden bat-boxes. This again highlights the fact that bat-boxes are not trees and may not replicate them as well as we might like to think.

Woodlice Woodlice (Oniscidea) are often found within PRF when inspections are performed. As aggregations are typically dislodged from the apex of the cavity the impression given is that the woodlice are actively extending the cavity upward and are therefore beneficial in the development of bat-roosts. This may in fact be true as the species most often encountered is Oniscus asellus which is a voracious devourer of rotting wood (Harding & Sutton 1985), however, reference to Sutton (1980) suggests that whilst woodlice found in trees do feed on dead plant material (and to some extent fungi), it is equally probable that they merely rest in the holes and are actually grazing on green algae on the bark. They might therefore be found in a cavity which is no longer actively decaying. __________________________________________________________________________________________ B2 - 5

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Most species of woodlouse don’t like being out in the open during the day, and actively avoid light, favouring dark and damp (but not wet) habitats (Hopkin 2003, Sutton 1980). PRF appear to encompass many (if not all) the conditions in which woodlice prefer to congregate during daylight hours (Sutton 1980). Thus, even if they do not assist in the development, the discovery of woodlice in a PRF may therefore be a good sign! This is however again, only a hypothesis. I have found woodlice in rot-hollows where bats had been present (see Figure B2.5), and I’ve found bats in cavities where woodlice had been present, but I’ve yet to find the two together. I wondered whether the bats were eating the woodlice but although an extensive review found references to woodlice being prey for little owls Athene noctua, common shrews Sorax araneus and hedgehogs Erinaceus europaeus, no reference to bats eating woodlice was found. It’s improbable that bats don’t come into contact with them, but perhaps they are unpalatable. Interestingly Hopkin (2003) highlighted that aggregations of woodlice excrete ammonia gas resulting in a distinctive urine smell, and suggested this might be the cause of their Dutch vernacular ‘pissebed’. Perhaps this is enough to deter bats from eating them. As an aside I can’t help wondering how similar this smell is to that cited for aggregations of bats.

Figure B2.5. Woodlice in two PRF, neither of which appears to be actively decaying. Note how clean, smooth and firm the walls of the PRF on the left are, that’s because it’s a brown long-eared bat Plecotus auritus roost. The void on the right however, although superficially suitable, has not yet (to my knowledge) held a bat.

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Slugs Of our 95 native slug species, 49 use woodland as their main habitat, and most feed only at night or in humid conditions (Harris & Harris 1991). The dusky slug Arion subfuscus is often encountered in and around PRF but, in my experience, dusky slugs do not prevent bats from roosting in a suitable PRF. In fact, as the slugs are also nocturnal and move a good deal more slowly than bats, the slugs typically enter PRF after the bats have returned and are already in residence. This has certainly been the case in two brown long-eared bat-roosts I have inspected; one in a Wound & Canker the other in a Hazard-beam. In the latter instance one bat was actually resting on a slug and had another two next to it, once the endoscope was manoeuvred past the two slugs to the side, another bat was found behind them with slugs on either side of it! Figure B2.6 shows an endoscope-view of the first brown long-eared bat and its slug pillow, and a close-up of the endoscope lens after the inspection which discovered the presence of the second bat.

Figure B2.6. Left: Brown long-eared bat Plecotus auritus resting on a dusky slug Arion subfuscus within a Hazard-beam. Right: The slimy endoscope lens after it had been pushed past the slugs to find the second brown long-eared bat behind.

Snails As with slugs, woodland snails are also nocturnal creatures (AA 1973), and may aggregate in damp PRF. But, again as with slugs, although tightly packed in snails may obstruct the entrance to PRF or congregate in the apex preventing a bat from taking residence, they do not necessarily force roost abandonment. Photo B2.1 on the following page shows one of three snail shells that were present in the base of Tear-out occupied by an individual Natterer’s bat. I have no idea whether it was the bat that evicted the snails (improbable as all the shells were __________________________________________________________________________________________ B2 - 7

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empty), but it does demonstrate that the presence of snails on one day, does not mean that bats won’t be present on another.

Photo B2.1. One of three snail snails (the other two are slightly above and to the left) which were found in the base of a Tear-out occupied by an individual Natterer’s bat Myotis nattereri, after apparently having been kicked evicted from a position in the apex. The shell is actually wedged in the roost entrance and the bat must have forced it's way in over the top!

BIRDS General Of the 30 species of birds that nest and/or roost in PRF only five; green woodpecker Picus viridis, great spotted woodpecker Dendrocopos major, lesser spotted woodpecker Dendrocopos minor, crested tits Lophophanes cristatus and willow tits Poecile montana habitually excavate their own nest-holes (Perrins 1979), with the nuthatch Sitta europaea and house sparrow Passer domesticus also excavating their own hole upon occasion. The remainder are opportunist, occupying pre-existing holes. A summary of the basic nest-requirements of each species is provided at Table B2.1 on the following page. __________________________________________________________________________________________ B2 - 8

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Table B2.1. Summary of tree nest site requirements of British birds (Taken from: Campbell (1953), Cramp (1985) & Ferguson-Lees et al. (2011). SPECIES

HABITAT

Mandarin Aix galericulata Goldeneye Bucephala clangula Goosander Mergus merganser Kestrel Falco tinnunculus Stock dove Columba oenas Ring-necked parakeet Psittacula krameri Barn owl Tyto alba Little owl Athene noctua Tawny owl Strix aluco

Riparian or lakeside woodland Riparian or lakeside woodland Riparian or lakeside woodland

Green woodpecker Picus viridis Lesser spotted woodpecker Dendrocopus minor Great spotted woodpecker Dendrocopus major Wren Troglodytes troglodytes Dunnock Prunella modularis Robin Erithacus rubecula Redstart Phoenicurus phoenicurus Spotted flycatcher Muscicapa striata Pied flycatcher Ficedula hypoleuca Willow tit Poecile montana Marsh tit Poecile palustris Coal tit Periparus ater Blue tit Cyanistes caeruleus Great tit Parus major

PRF

LOCATION

HEIGHT

Rot-hollows

Stem & branch

Ground to 10 m

Rot-hollows

No data

1.4 m – 5 m

Rot-hollows

Stem as pine and birch favoured

Up to c. 7.5 m

All

Rot-hollows

Stem & branch

1 m – 22 m

Wooded habitat (parks, riverside, hedgerows)

Rot-hollows & epicormic shoots of lime Woodpecker holes & rothollows

May be several feet down in tree

No data

Stem & branch.

No data

Woodland Woodland edge, hedgerow, isolated trees (parks etc.) Hedgerow, isolated trees in agricultural land Deciduous woodland, hedgerow, parkland Wooded habitat rather than woodland (parks, hedgerows etc.) Woodland, parkland Deciduous & coniferous woodland and parkland Woodland edge, hedgerow, parkland, isolated trees Woodland edge, hedgerow, parkland, isolated trees Woodland, hedgerow, parkland

No data.

No data

Stem.

0.3 – 12.2 m

Rot-hollows

Stem & branch.

Ground to 12 m

Stem & branch.

1 m – 15 m

Stem & branch.

1 m – 25 m

Stem & branch.

0.4 m – 20 m

No data

Ground to 10 m

Rot-hollows and behind ivy

No data.

0.5 m – 3.5 m

Excavates new nest-hole each year, sometimes below the one of the previous year Excavates new nest-hole each year Excavates new nest-hole each year Woodpecker holes & rothollows

Rot-hollows and behind ivy

No data.

Ground to 5 m

Rot-hollows, behind ivy and bark

No data.

Ground to 3 m (to c. 7.5 m)

Behind ivy and bark

No data

Ground to c. 6 m

Stem & branch

1.8 m – 10 m

Stem

Ground to 3 m

Rot-hollows & old willow tit holes

Stem

Ground to 3 m

Conifer and sessile oak woodland, parkland

Mouse holes, behind bark, low woodpecker-holes

Stem & typically stump

Typically close to the ground but up to 4.5 m

All

Rot-holes, horizontal cracks, vertical splits &behind bark

No data

Woodland, parkland

Tree hole

No data

1-5 m (to 12 m)

No data

Ground to c. 9 m typical (up to 13.5 m)

Stem & branch

1.9 m – 20 m

No data

Below 2 m, but exceptionally up to 16 m

Stem

1.2 – 21 m

Stem & branch

Ground to 15 m

Woodland, parkland Woodland edge, tree-lines streets Sessile oak woodland, parkland Woodland (damp). Birch, willow and elder favoured Woodland & wooded habitat (parkland, orchards etc.)

Crested tit Lophophanes cristatus

Native pine woodland (Scotland)

Nuthatch Sitta europaea

Woodland, hedgerow, parkland

Treecreeper Certhia familiaris

Woodland, parkland

Jackdaw Corvus monedula Starling Sturnus vulgaris

Rot-hollows in big old trees Green woodpecker-holes and rot-hollows

All All

Woodpecker holes & rothollows Excavates new nest-hole each year (Perrins 1979)

Woodpecker holes & rothollows. Excavates own holes in dead stumps (Perrins 1979) Rot-hollows & woodpecker holes (may excavate hole) Vertical splits, behind ivy & bark Rot-hollows (up to 3 m down in hollow tree) Woodpecker holes & rothollows

House sparrow Passer domesticus

Parkland, hedgerow, isolated trees (in villages and towns)

Rot-hollows, (may excavate nest hole)

No data

At least 3 m

Tree sparrow Passer montanus

Woodland, parkland

Rot-hollows, vertical splits

No data

2m–5m

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Competition In the UK the bird breeding season is generally accepted to last from 1 st March through 31st July and thus a great many potential bat-roost sites may be occupied by birds during this period. Some bird species may also compete with bats for specific tree features; treecreepers Certhia familiaris, which typically nest behind loose bark (AA 1973), might compete with barbastelles Barbastella barbastellus, and while the coal tit Periparus ater appears to prefer nest sites with a narrow vertical slit, the great tit Parus major and willow tit favour nest sites with circular holes (Perrins 1979). Most birds may simply put bats off by their presence, but starlings Sturnus vulgaris often take over the nest holes of woodpeckers (AA 1973) and will drive out (and possibly kill) noctules they encounter (Howes 1979, Mason 1972). Interestingly, starlings Sturnus vulgaris also nest in soffits on buildings, under the eaves and also in the loft (Ferguson-Lees et al. 2011), so they probably usurp a good many roost sites from house roosting bat species and not just noctules Nyctalus noctula. As such, a review of any breeding bird surveys performed may yield valuable clues as to the potential presence of PRF in the focus woodland for attention later in the season when many will have left. However, bear in mind that as with bats, birds use tree-holes for different periods; starlings vacate nest holes to aggregate in huge roosts in reedbeds etc. in the autumn, leaving their nest-holes open to bats, in contrast ring-necked parakeets Psittacula krameri remain in nest-holes year round.

Photo B2.2. A Canker on an ash Fraxinus excelsior which unfortunately has been colonised by jackdaws Corvus monedula. Furthermore, the British tits do not hibernate, but often leave the woodland during the day to __________________________________________________________________________________________ B2 - 10

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visit urban areas, returning at night to roost (Perrins 1979). As a result, even in the winter months, many PRF that are unoccupied by birds during the day when the bat enthusiast is out and about, may be occupied by birds at night. Whether bats and birds coexist in a shiftsystem is unknown. In the London area, ring-necked parakeets Psittacula krameri may occupy holes in parks and larger gardens that might have previously been occupied by bats, and in particular Daubenton’s bats Myotis daubentonii and noctules Nyctalus noctula. Ring-necked parakeets can’t enter holes smaller than 40 mm in diameter (Strubbe & Matthysen 2009), but may open holes up themselves or nest in larger (40-80 mm (Butler 2003)) natural tree holes (especially in ash), and in old green Picus viridis and great-spotted woodpecker holes Dendrocopos major, typically at heights of 4-14 m (Ferguson-Lees et al. 2011). Nest sites are vigorously defended with one adult usually on guard near the nest hole (Ferguson-Lees et al. 2011).

Avian bat predators General In the UK the principal avian predators of bats comprise tawny owls Strix aluco, barn owls Tyto alba, kestrels Falco tinnunculus, sparrowhawks Accipiter nisus and Hobby Falco subbuteo. Long-eared owls Asio otus also take bats occasionally (Glue & Hammond 1974, Village 1981). Raptors have been estimated to account for 11% of the mortality of British bats annually (Speakman 1991). Tawny owl Strix aluco Tawny owls take Bechstein’s bats Myotis bechsteinii (Krzanowski 1973, Ruprecht 1979, Cramp 1985), Daubenton’s bats Myotis daubentonii (Cramp 1985), Natterer’s bats (Cramp 1985), Leisler’s bats Nyctalus leisleri (Cramp 1985), noctule (Cramp 1985), Nathusius’ pipistrelle Pipistrellus nathusii (Cramp 1985, Ruprecht 1990) and brown long-eared bats (Glue 1970, Simms 1979, Cramp 1985). Barn owl Tyto alba Barn owls take barbastelles (Cramp 1985), Bechstein’s bats (Cramp 1985), Daubenton’s bats (Cramp 1985), Natterer’s bats (Krzanowski 1973, Cramp 1985, Love et al. 2000), Leisler’s bats (Ruprecht 1979, Cramp 1985), noctules (Ruprecht 1979, Cramp 1985), Nathusius’ pipistrelles (Cramp 1985, Ruprecht 1990) and brown long-eared bats (Glue 1970, Simms 1979, Cramp 1985). Kestrel Falco tinnunculus Kestrels are known to predate brown long-eared bats (Glue 1970, Simms 1979), but bats of several species are probably taken (in small numbers) regularly in summer (Cramp & Simmons 1979). __________________________________________________________________________________________ B2 - 11

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Sparrowhawk Accipiter nisus Sparrowhawks are thought to take Leisler’s bats (Robson 2008). Hobby Falco subbuteo Hobbies take bats up to the size of noctule (Cramp & Simmons 1979). It is of particular note that all the bat species recorded as avian prey in the following review are known tree-roosters. Furthermore, aside of Brandt’s bat Myotis brandtii (the status of which as a regular occupier of trees is in doubt), the list is comprehensive. The house-roosting bat species are all notable by their absence from published accounts. Great spotted woodpecker Dendrocopos major Great spotted woodpeckers are known as a serious predator of small hole-nesting birds (Perrins 1979). Individual accounts exist of great spotted woodpeckers having taken small rodents (live), a newly-born squirrel and carrion (Cramp 1979). Furthermore, it’s known the males defend the roost holes within their territories (Cramp 1979) and it has been speculated that woodpeckers might kill bats they find ‘squatting’ in a favoured roost-hole (Czeszczewicz & Walankiewicz cited in Ruczyński & Bogdanowicz 2005).

MAMMALS General There are four species of mammal; red squirrel, grey squirrel, common dormouse and pine marten, that may compete with bats for PRF, although none use PRF as their primary nest sites and all save grey squirrel have a restricted distribution in the British Isles. A summary of the basic nest-requirements of each species is provided at Table B2.2. Table B2.2. The tree nest site requirements of red squirrel, grey squirrel, common dormouse and pine marten based on accounts in Harris & Yalden (2008). SPECIES Red squirrel Sciurus vulgaris Grey squirrel Sciurus carolinensis Common dormouse Muscardinus avellanarius Pine marten Martes martes

HABITAT Pine woodland favoured.

PRF

LOCATION

HEIGHT

Rot-hollows.

No data.

Above 6 m.

Woodland, parkland.

Woodpecker holes & rothollows.

No data.

Woodland, hedgerow.

Rot-hollows.

No data.

Ground to 10 m.

Woodland.

Rot-hollows.

No data.

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I encounter grey squirrels regularly in PRF and would suggest they are the principal mammalian competitor that bats have to contend with for favourable roost sites. A very distant second would go to common dormice (I've found four now; one in a Tear-out and three in Hazard-beams at angles of less than 30°). In addition, I find wood mice moderately frequently in PRF up to c. 2 m in the winter, and I have also been shown yellow-necked mice in dormouse boxes by Colin Elford (Forestry Commission Ranger, Ringwood Beat), one of which was sited over 6 m up in a larch, so they certainly do climb. Principal mammalian predators appear to comprise stoats Mustella erminaea and weasels M. nivalis, and may also comprise both species of squirrels and pine martens.

Squirrels Where they can, squirrels make dens inside hollow trees, and often take over woodpeckerholes, enlarging the entrance (Shorten 1954, H. Andrews pers obs.). In Somerset, the abundant frost-cracks within the woodlands around the Quantocks are also often colonised by grey squirrels, apparently in preference to woodpecker holes (H. Andrews pers obs.). Where frost-cracks have been colonised, the gnawing at the entrance apex produces a conspicuous ‘key-hole’ shaped entrance, with a downward orientation caused by ‘flaring’ of the woundwood tissue (see Figure B2.7).

Figure B2.7. Characteristic flaring over squirrel Sciurus carolinensis den entrances. __________________________________________________________________________________________ B2 - 13

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Interestingly, Shorten (1954) also describes the infection of decay organisms in heartwood and how squirrels exploit this. Shorten suggests that, as the rot progresses, squirrels may start to excavate the pulpy tissue, enlarging the hole. As the process takes a long time the squirrels gnaw at the ring of callus to ensure the entrance remains large enough (I’m sure many readers will, as I, have encountered such reddish-orange gnawed bark around knot-holes). Such dens may be in use for twenty years or more.

Figure B2.8. Characteristic gnawing around entrance holes on dens occupied by grey squirrels Sciurus carolinensis. Note the slugs returning, and also the line of staining below the entrance which originates from the gnawed sapwood (not urine). __________________________________________________________________________________________ B2 - 14

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If the trees have no hollows, then squirrels resort to making a drey (Shorten 1954). Grey squirrel dreys comprise a large bundle of brown leaves and twigs, typically built in a canopy fork of an oak or beech limb. The drey of a red squirrel is smaller (roughly the size of a football) and weaved with leafless twigs, grass, moss, and stripped bark (typically honeysuckle). The internal cavity is c. 23 cm across and lined with grass, moss, shredded bark and leaves. Access is via a short tunnel.

Photo B2.3. Two grey squirrel Sciurus carolinensis dens in woodpecker-holes on a pedunculate oak Quercus robur. Note the staining below the upper more regularly used den. This is caused by sap running where the squirrels gnaw at the entrance callus woundwood to keep the entrance large enough for them. __________________________________________________________________________________________ B2 - 15

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Shorten (1954) describes many dreys being built, but used only for short periods in summer to evade swarming fleas and louse populations in more favoured dens. Dreys are abandoned by late summer and early autumn, as winds increase and pest infestations decrease. Grey squirrels do successfully compete with noctules for PRF (Mackie & Racey 2008). As grey squirrels appear to favour Woodpecker-holes for winter dens, it’s therefore probable that the presence of grey squirrels has a negative effect upon Bechstein’s bats, Daubenton’s bats and Leisler’s bats which also occupy woodpecker-holes and void-type PRF. Grey squirrels do occupy Frost-cracks in several of my local woods, but their presence is limited to wider cracks with soft heartwood. Noctules Nyctalus noctula can exploit isolated trees that are not attractive to squirrels as nesting places (Shorten 1954). It is therefore possible, that the noctule is the least affected by grey squirrels Sciurus carolinensis, despite being the only species for which any effect has been described.

Mice Whilst woodmice and yellow-necked mice do climb, they don’t appear to be competitors for PRF, firstly because they make their nests in the base of shallow features not ordinarily occupied by bats, and secondly because they tend only to occupy tree features above 2 m, in the winter months. Dormice, however, are an entirely different proposition. I have found three dormouse nests in pedunculate oak Quercus robur Hazard-beams (see Figure B2.9) all of which were at angles of less than 30°.

Figure B2.9. dormouse Muscardinus avellanarius nest in a Hazard-beam. The honeysuckle bark nest was in the outer apex (shown on the left side of the left image). __________________________________________________________________________________________ B2 - 16

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I have found a dormouse nest in a vertical Tear-out on a pedunculate oak (see Figure B2.10) that appeared superficially suitable for barbastelle, Myotids and brown long-eared bats, and Whilst the mice themselves may be timid, their nests are surprisingly robust and fill the apex of the PRF entirely.

Figure B2.10. Left: My endoscope illustrating a Tear-out in a pedunculate oak Quercus robur holding a common dormouse Muscardinus avellanarius nest, you can see honeysuckle Lonicera spp. debris in the base. Right: Endoscope-view of the dormouse nest which is about 20 cm up in the spire.

Pine marten Finally we come to the pine marten. Pine marten do occupy hollows in trees for lairs and breeding dens (Step 1946, AA 1973, Harris & Yalden 2008), and have been known to kill squirrels and take over their nests (Burton 1968). It is probable that they are competitors with bats for PRF, but I can find so little of their nesting ecology in published accounts, that I cannot even begin to hypothesise as to which bat species they might compete with.

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Mammalian bat predators Squirrels Sciurus spp. No conclusive evidence that squirrels predate bats was found during this review. However, squirrels are known to predate nesting birds (Hewson et al. 2004). The red squirrel may destroy eggs, fledglings and adult birds (Hanson 1934, Shorten 1954, Burton 1968), and the grey squirrel in particular is cited as regularly taking young tits Parus spp. (Perrins 1979). In addition, grey squirrels have also been recorded fighting (and even killing) rats Rattus norvegicus, stoats, rabbits Oryctolagus cuniculus, leverets Lepus europaeus, red squirrels and cockerels Gallus gallus, and are known to raid bird’s nest and kill fledgling young, typically cracking the skulls open (Shorten 1954). Shorten (1954) also suggested that grey squirrels will eat parts of dead birds they found, usually concentrating on the head of young. The principle argument for the suggestion that bats are unattractive to predators is that they aren’t worth the effort. One cannot help but observe that there isn’t much effort in attacking a torpid bat. Squirrels don’t hibernate (Shorten 1954) and oak Quercus spp. and beech Fagus sylvatica only produce a large amount of fruit in ‘mast’ years; typically every six to seven years, with some years totally bare (Milner 2011). I can’t help wondering what happens to bats in these years; are they (and nestling birds) at greater risk of predation by squirrels due to the latter’s starvation? As squirrels don’t hibernate, and bats do, squirrels are active and hungry when bats are most vulnerable. I had originally thought that bats roosting in an upward ‘spire’ would be out of reach of squirrels, and hypothesised that as the red squirrel has a c. 21 cm head and body length and the grey c. 27 cm head and body length, bats would typically hibernate above c. 30 cm. This does not appear to be the norm. This year I placed more emphasis on my observations of squirrels and recorded a grey squirrel over 60 cm up in a decay spire within a frost-crack (See Figure B2.11 on the following page). I am confident this squirrel was asleep when I found it. The Frost-crack was conspicuous in its physical appearance and a further three more or less identical cracks have been found on this slope in this woodland. All have gnawed entrances, all have ‘grease-blackening’ at the entrance, all are clean, smooth and firm inside, and whilst only one squirrel has been found at home, two of the other three were found to have squirrel fir collected on ribs in the wood in the cavity apex, all of which are above 50 cm internal height. Stoat Mustella erminaea & weasel M. nivalis The stoat and weasel climb much better than most people realise and can easily climb even trees with smooth bark, including young ash. They are also very slender and have no __________________________________________________________________________________________ B2 - 18

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difficulty getting through small holes, even down to the c. 3 cm diameter hole of a blue-tit Cyanistes caeruleus nest-box (Perrins 1979).

Figure B2.11. A grey squirrel Sciurus carolinensis sheltering 60 cm up in the apex of a Frost-crack. Again, note the flaring of the bark around the upper arch of the entrance hole, which is distinctive of winter dens.

Barrett-Hamilton (1910) cites instances on record of bats being captured by stoats and Vonhof & Barklay (1996) suggested (albeit in Canada) that bats in their study were selecting taller roosts to avoid weasels. Weasels do nest in hollow trees (Step 1946) and it’s known that the weasel is the most serious predator of young tits (Perrins 1979). Furthermore, weasels __________________________________________________________________________________________ B2 - 19

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hunt at night, often patrolling a hedgerow or woodland edge, and would therefore logically be in the right location at the right time in order to see aggregations of bats emerging. McDonald & Harris (1998) put forward the suggestion that weasels might well gain access to bats in the base of a woodpecker hole which, coupled with their early emergence, would appear to put Leisler's bats and noctules most at risk. Pine marten Martes martes Pine marten do occupy hollows in trees for lairs and breeding dens (Step 1946, AA 1973), and on the Continent Ruczyński & Bogdanowicz (2005) considered that they were a predator of both noctule and Leisler’s bats. In the British Isles pine martens do take nestling birds, and have also been known to kill squirrels and take over their nests (Burton 1968), but as the species is a nocturnal hunter it would be logical to suppose that new-born bats would be most at risk.

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TREE-ROOSTING BATS - MAPPING PRF GENERAL Ornithologists have two ways of finding birds’ nests; searching, or by getting the birds to show it to them (Campbell 1953). The same applies to bats. However, whilst the first method is open to all naturalists, when finding tree-roosts the second method would require radiotracking which requires a high-level licence and a terrific amount of expertise and expense. What I know about radio-tracking could be written on the back of a fag-packet (what I know about bats on a shoe-box), but I find roosts, so do not despair. Campbell defines visual inspections of habitat as ‘cold-searching’ as you’re looking for the resting place and not the target species. This is what I do; I read the habitat and then put myself in the best possible position to be able to see the PRF if they are present. Cold-searching is by far the most civilised way of finding tree-roosts, and Campbell himself pointed out in relation to birds, for a study involving all the nests of all the species in a particular area, cold-searching is the most useful method. But bats are not birds I hear you say (as did someone else, although in my opinion rather naively; jet aircraft are not birds either but I learnt to identify them by the sounds they make on the ground and in the air so I’m damn sure you can do the same with bats, it’s just the kit isn’t quite up to it yet, but it will get there). Bats fly, what goes up must come down, and when it does it roosts in tree holes so the same principles apply. Cold-searching is effective. Furthermore, it’s satisfying on a welfare level, terrifically rewarding on a personal level, and it’s also damn good exercise which is good on a relationship level. Bear in mind, the form and abundance of PRF in any habitat has nothing to do with the size of the trees. This is because the size of the trees has nothing to do with the continuity of management in that habitat. Great-spotted woodpeckers Dendrocopos major colonise polestage forest when trees are still of relatively small diameter, using wind-snapped pine Pinus spp., larch Larix spp. and birch Betula spp. for nesting (Harris & Harris 1991). If the woodpeckers are there, then it is logical to suppose the decay fungi are there… I’m concerned by just how much our understanding of tree-roosting ecology may have been retarded by the suggestion that bat-roosts are typically found in trees over 1 m in diameter. If this is true (and it isn't my experience), might it not be because naturalists have a tendency to home-in on the biggest and oldest trees? It might be reasonable to suppose that maternity roosts might more often be recorded in larger trees, but that transitory, and hibernation roosts would logically be more numerous overall and more often recorded in far smaller trees (in December when I began this text I had just recorded a brown long-eared bat Plecotus auritus hibernating in a sessile oak Quercus petraea with a Diameter at Breast Height (DBH) of 27 cm, and a noctule Nyctalus noctula hibernating in a sessile oak with a DBH of 19.5 cm. In April I recorded a Natterer’s bat Myotis nattereri in a 17.5 cm DBH stem and a barbastelle Barbastella barbastellus in one of 17 cm DBH, these are not atypical records, and I have well into double figures.

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MAPPING OBJECTIVE The objective of PRF Mapping is to locate and record all the visibly identifiable potential roost trees on a large-scale plan in order that they can be targeted in later, more detailed, surveys.

MAPPING EQUIPMENT To complete the mapping surveyors should be equipped with:  Compass;  Binoculars;  A bundle of canes marked with the surveyors identification colour;  An aerosol-can of forestry marking paint or roll of hazard tape; and  A handheld GPS. If you're mapping a wood, try to get a large-scale plan, most woodland owners have one. Plantations always have a stock map showing compartments, rides and racks (narrow routes created in compartments during thinning to facilitate the removal of felled trees). Stock maps are worth their weight in gold when you're PRF mapping as they provide landmarks that facilitate navigation; a big plus in dense homogenous habitat.

MAPPING METHOD Talking The first stage of any assessment of a wood should be to talk to the Gamekeeper and Ranger (or equivalent), if there is one. If you're in a wood or plantation you’re looking at how intensive management has been, and is now. Rangers will be able to give you the background you need re: stock; age, species, rotational management, pest species, fungi etc. Plantations comprise a ‘crop’ of trees, like a field holds a crop of wheat Triticum spp. etc. As such the woodland compartments are managed in rotation, planted, grown, and harvested at different rates depending on the timber species. The trees are therefore felled before they reach old age. Furthermore, PRF are faults in the timber crop, and many are caused by crop diseases that the Ranger will be keen to eradicate. Well managed woodlands develop few PRF, and those that begin to develop are weeded out, like unwanted flowers in a garden. If you're searching a river, don't be shy of talking to fishermen; they're out at dusk and dawn and they're interested in the natural world. They have always seen bats, and fishermen are creatures of habit; they like to return to their favoured swim. Ask them what time they typically see the bats first and last and use that information to try and narrow down where the roosts are. __________________________________________________________________________________________ B3 - 2

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Finally, talk to farmer workers you see out in the field. Farmers very often do their own tree surgery (such farmers are known as 'agricultural stunt-men' in arborist circles), and they may be able to give you some background about the trees on their farm. Note: Save where academics have taken up the gauntlet, the descriptions in generalist texts (this one included I’m afraid), tend to omit regional differences brought about by changes in the resident bat fauna. This is particularly the case in Ireland where surprising habitat preferences may yet be discovered by bats filling niches occupied by an entirely different species in England. I am a great believer in local knowledge; just as no one knows a child better than their mother, no one knows the habits of local bats better than the local Bat Group; don’t be afraid to ask!

Timing Watson (2006) sets out that leaves have a limited life-span; typically from April to November with most leaf-loss in the October/November period. I’d go a little later than that and suggest December for the start of the ground survey season, but I’m in Somerset and it will doubtless vary the further north you go. Milner (2011) suggests that oaks Quercus spp. may come into leaf as late as mid-May, but from personal experience when I see the horse-chestnuts Aesculus hippocastanum come into leaf around mid-March I know I’ve got a maximum of four weeks before the canopy will close, typically by the end of April for pedunculate oak Quercus robur and mid-May for ash Fraxinus excelsior. Horse-chestnut is a useful early warning tool (and is probably my favourite tree). Whilst ultimately it is for the surveyor to decide whether visibility was adequate to complete a ground assessment, surveys outside the optimum period should be treated with caution. I would suggest that in consultancy reports the section on Methodological constraints should demonstrate that the survey was possible using photographs to illustrate that all of the tree could be seen. Aside of anything else, if you can’t photograph all the areas of the tree, then I would suggest you would find it very difficult to photograph a PRF and thereby find it again later, which would rather make a mockery of a ground survey. Mitchell-Jones (2004) highlighted the fact that several species of bats use PRF that are far from obvious; ground mapping is far from comprehensive even when the foliage is off, when foliage is survey coverage is reduced significantly. I would like to direct the reader’s attention to Figure B3.1 on the following page; I think it speaks for itself.

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Figure B3.1. Two views of the same woodland edge. Top: January. Bottom: August.

Mitchell-Jones (2004) recommended the period November through April as the best time to __________________________________________________________________________________________ B3 - 4

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carry out ground surveys. I have followed this recommendation for many years and find, with the caveat that surveys may still be performed in May, that this is the only period in which ground mapping of woodland and riparian PRF is possible. Furthermore, in only the most exceptional circumstances is it is possible to adequately inspect the full structure of even an individual mature broadleaved tree in mid-summer from the ground. I have myself recorded a branch roost holding an individual brown long-eared bat Plecotus auritus at 17 m in a beech Fagus sylvatica. When I came back in August to check it, I couldn’t see it from the ground at all, and it took a team of us a good few minutes to find it, despite the fact we knew broadly where it was, and we were using a 25 m Mobile Elevating Work Platform (MEWP). Obviously, as every tree surgeon knows, the problem can very easily be overcome by climbing the tree and inspecting it in this way, and where time-constrained work (such as remedial safety inspections etc.) affects only individual or very small numbers of trees, this would be the most sensible course of action.

Transects I respect the fact that all of you are perfectly well able to work your way round a site, but I thought I'd set my woodland transect system out here just in case anyone was struggling. In order that I pick up as many of the visibly identifiable potential roost trees (i.e. all trees holding PRF) as is reasonable practicable, I use a system of transects walked on a consistent alignment from one side to another. This system does work when I working alone (we all do it, whatever Messrs' H & S may say to the contrary), but is far more effective with three surveyors each 10 m apart. In larger woodlands it is wise for surveyors to mark their start point on the woodland edge with canes (carrying a small bundle with them for future use), check the compass for orientation and then walk in parallel on that line, looking for potential roost features within their field of vision. Each time a feature is observed the surveyor cries ‘halt’, the line stops and the surveyor in question circles the tree with forestry marking paint at chest height so it is visible from any angle. The surveyor then marks the tree with a number (always on the southern side), notes the location (GPS) and transect number, takes a note of the tree species, the form of the PRF, its approximate height, its location (stem or branch), its orientation (north, south, east, west etc.) and finally whether or not the PRF is safely accessible. Having done so, the transect continues. When the northern edge of the woodland is reached the line moves up the woodland edge to be 10 m on, and turns to head south proceeding as before. Finally, the woodland edge is performed from outside by one surveyor. An example of this form of transect is provided at Figure B3.2.

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Figure B3.2. Example of a PRF mapping transect. Experience in the application of this method has shown that it is most effective with a team of three surveyors. Two tend to stray off line, a team of four results in irritatingly high numbers of pauses. Furthermore, with three; one can be doing the final circuit of the woodland while the other two crack on with the inspections. It is accepted that in some cases it may be more appropriate to mark the trees with some form of tape rather than forestry marking paint (you can also write on the tape). I always use paint as it has no negative effect on the commercial value of the timber, it facilitates repeat visits, and I’m working in closed sites with little or no public access.

PRF Recording Obviously you’re look for PRF (see Section A, Chapter A4, A6 & A10), but PRF aren’t always obvious. Here’s a throw-away hint from our old friends Mattheck & Breloer (1994); “a rib is a symptom of a crack in a tree, while a swelling or bulge can indicate a cavity.” There is nothing more satisfying than being told, “no, there’s nothing there”. And then getting up the tree, finding a rib, tracing it along and finding a hole, and then finding some bat-poo; everyone thinks you’re Gandalf (or Geronimo) if you can pull that one off (only once, but once is enough…). All PRF are safely accessible by ladder and/or rope-climb may then be subject to daytime inspection. For some that are not safely accessible, such as those at great height in dead-trees, it may be possible to access them using a MEWP, however in the vast majority of cases trees __________________________________________________________________________________________ B3 - 6

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that are unsafe to climb will be subject to dawn-return surveys supported by ultrasound detectors. Each of the individual PRF mapped can be plotted onto a map and entered into a tabulation (see Table B3.1 for an example) and in order to direct further survey. Table B3.1. Specimen PRF mapping form. TRANSECT No.

TREE No.

O.S. Ref.

SPECIES

PRF FORM

LOCATION (stem/branch)

HEIGHT

ORIENTATIO N

ACCESS (Ladder/rope/ Nil)

A word about LOCATION: In its natural form, without the intervention of management, a fully grown tree has a stem (or stems) with limbs, branches (major and minor), twigs, and leaves which can be broadly categorised as follows:  Stem: The main and largest diameter section of the tree, typically upright. The section that holds the roots. It sometimes helps to isolate the stem by thinking about how you would go about pollarding the tree. Note: some trees (notably outgrown coppice ash Fraxinus excelsior and sessile oak Quercus petraea) are multistemmed.  Limb: The junction between stem and limbs is the first division at the top of the stem where the one obvious section divides into two or more sections of approximately equal diameter to begin forming the crown. Limbs may continue in a more or less vertical fashion or may spread widely. Limbs may also come off the stem at more or less right-angles below the main crown division.  Major branch: The junction between limbs and branches is the second division where an individual limb again subdivides into two or more sections of approximately equal diameter. Branches may also come of limbs at more or less right-angles below the main and ultimate division. In mature trees a major branch is over 10 cm diameter. Climbers should not anchor to anything less than a major branch.  Minor branch: Branches may again sub-divide and with mature trees a minor-branch may be classified as 1 – 10 cm.  Twig: Any section up to 1 cm diameter. These categories may seem obvious, even irrelevant, but I have set them out here as it really does help to get into the practice of labelling them even if it is only to be confident in making the distinction between stem and branch. This is particularly pertinent when a particular feature is catalogued within a report or letter; GPS is somewhat vague on the ground and being told a particular feature is on a stem in a wood only to find, after half an hours searching, that it is on a vertical limb way above the bole, is a tad frustrating!

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TREE-ROOSTING BATS - TREE-ROOST FIELD-SIGNS INTRODUCTION

“It would be surprising if our views were not improved by standing on our predecessors’ shoulders, and any comments which appear critical should be taken in this vein.” G.C. Evans, Journal of Ecology, 1956, 44: 392. Technology has advanced terrifically in the years since I first started looking for tree-roosts. We accept radio-tracking studies as the norm for unravelling tree-roosting ecology now, but even ten years ago this was almost unheard of. Back in 2001 endoscopes were very hard to come by and when I got my first in 2005 I was the envy of everyone I knew. By 2010 the new video endoscopes were in widespread circulation, but still not many people owned one, and in 2012 I was one of the first people in the UK to take delivery of a Ridgid C300 photographic scope. Before this kit became available naturalists found most tree-roosts by accident and, as one would expect, these were typically large roosts of big bats; noctules Nyctalus noctula, and very little else. It's an odd observation, but radio-tracking tree-roost studies don't tend to describe field-signs, and when I finally got my hands on Barrett-Hamilton's A History of British Mammals: Vol. 1 – Bats (1910) I was surprised to see how many of the field-signs he lists are still in use today. Barrett-Hamilton's (1910) A History of British Mammals is now out of copyright in the United States and can be purchased on www.amazon.co.uk. Volume 1 – Bats can be found for only £18.99 at http://www.amazon.co.uk/gp/product/1149395095/ref=oh_details_o06_s00_i00 and should now form a stock part of your library.

In order to provide what I believe is a robust basis for interpreting probable bat occupancy in unoccupied PRF, in this section I have listed field-signs that have historically been cited as indicators of bat occupancy in trees, with an assessment of how useful I believe they are based on my own experiences. The following text will doubtless be controversial; I make no excuses for this. What I will say however, is that I have the benefit of technology and of massive advances in the understanding of how trees work. I wish to make it absolutely clear that I am not suggesting that historically naturalists were wrong, or that any author has sought to mislead. What I am saying is that many of the field-signs historically put forward are more often complimentary to other evidence, rather than diagnostic in themselves. All the following field-signs have been produced in texts offering guidance in tree-roost surveys. __________________________________________________________________________________________ B4 - 1

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LIVING OR DEAD BATS Finding bats in a PRF upon any inspection is always very satisfying, but that is because it's moderately uncommon. Finding dead bats is rarer still. I've only encountered a dead bat in a tree-roost once, and this was (sadly) a dead baby brown long-eared bat Plecotus auritus (see Photo B4.1).

Photo B4.1. Dead baby brown long-eared bat Plecotus auritus in the base of a maternity roost in a sessile oak Quercus petraea Frost-crack. __________________________________________________________________________________________ B4 - 2

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SCRATCHES AROUND THE EDGE OF A PRF I have never encountered a tree-roost with scratches that could be attributed to bats, nor have I ever seen such scratches on a wooden bat-box. The only physical signs I find in bark are caused by grey squirrels Sciurus carolinensis (see Photo B4.2) and birds.

B4.2. A noctule Nyctalus noctula lekking roost entrance in a woodpecker-hole. The scratches are c. 4 mm across and I am sure they are attributable to the teeth of grey squirrels Sciurus carolinensis.

SMOOTHING/POLISHING OF SURFACES AROUND A POTENTIAL ENTRANCE In contrast to the presence of scratches, smoothing is also often cited as a predictive field-sign and here, with a caveat, I concur. The caveat is that in void-type PRF a polished appearance around the entrance which appears dull and blackened (as though gripped by countless grubby hands) is, in my experience, more often attributable to grey squirrels (see Photo B4.3). Internal smoothing is however quite another matter.

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Photo B4.3. The characteristic long grey hairs glued round the smooth rim of the entrance to a grey squirrel Sciurus carolinensis den in a great spotted woodpecker Dendrocopos major hole in a pedunculate oak Quercus robur.

Photo B4.4. Natterer's bat Myotis nattereri. Note how polished the wall is above the bat, almost glassy. __________________________________________________________________________________________ B4 - 4

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In my experience, the number one indicator of bat occupancy within a PRF is cleanliness; if it’s clean, smooth and dry all the way up (see Figure B4.1) with no dust, debris, aggregations of general muck, then something has to be keeping it clean and in the greater percentage of PRF I have inspected, that something has turned out to be a bat, or a group of bats.

Figure B4.1. Unoccupied summer tree-roosts: Top left: noctule Nyctalus noctula. Top right: Brown long-eared bat Plecotus auritus. Bottom: Natterer's bat Myotis nattereri. Note just how clean and polished the walls are. __________________________________________________________________________________________ B4 - 5

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Photo B4.5. Internal walls of a brown long-eared bat Plecotus auritus hibernation roost in a sessile oak Quercus petraea. Winter roosts may have damp/wet walls which are 'bobbled' rather than smooth, but firm and clean rather than soft and sludgy.

URINE STAINING BELOW A PRF I have never seen staining around a tree-roost that I could conclusively attribute to the bats inside. Furthermore, I have looked in more PRF than I care to mention, that had text-book staining but were never occupied by roosting bats. An example is provided at Figure B4.2 and Photo B4.6. I can’t help but wonder why, when this is so often cited as an indicator of bat presence in trees, urine-staining is not mentioned at all as in indicator of bat presence in buildings? I’ve found and monitored roosts of serotine Eptesicus serotinus, whiskered bats Myotis mystacinus, common pipistrelle Pipistrellus pipistrellus, soprano pipistrelles Pipistrellus pygmaeus, brown long-eared bats and lesser horseshoe bats Rhinolophus hipposideros in buildings and I’ve never seen urine staining below the entrance.

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Figure B4.2. An oak Quercus robur with a discontinuous woodpecker-hole. Left: The staining down the tree has killed the moss and algae. Top right: the hole is enlarged by grey squirrels Sciurus carolinensis. Bottom right: The hole is damp and sludgy with fungal growth on the top right wall (see the enlarged close-up at Photo B4.6).

Photo B4.6. Fungal growth on the inner wall of the snot-hole shown in Figure B4.2. __________________________________________________________________________________________ B4 - 7

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It’s also odd that this staining is only ever present outside Woodpecker-hole roosts, why not on all the roosts? It’s odder still when you think that Woodpecker-holes have the entrance at the top of the void, which leaves a lot of room for urine, yet we never find Woodpecker-holes filled to the brim with droppings. But if it isn't bats that produce the staining, what is it? As all the photographs I have seen of staining relate to noctule roosts in Woodpecker-holes, I wondered whether it might be a product of the fungus that made the site attractive to woodpeckers in the first place. A typical symptom of fungal decay of heartwood is a change in colour, usually a dark brown or purple stain (Cartwright & Findlay 1958). As wood-rotting fungi obtain their energy by a process of respiration and in certain wood-rotting fungi this process produces considerable quantities of water (ibid). When an exit hole is provided (such as a woodpecker hole or a knot-hole) it is not unusual for the stained moisture to run down the outside of the tree (author pers obs.). In addition bacteria exude a fluid known as slime-flux, typified by a dark wet line down the tree which, unlike water, kills all the epiphytes in its path (Watson 2006). In my experience, staining under a Woodpecker-hole or Knot-hole is far more often the result of an advanced wet-rot infection than the presence of bats.

BAT-DROPPINGS Droppings rate as my No. 2 most reliable field-sign (see Figure B4.3). Their position at No. 2 may at first site seem odd, but think of the types of PRF; not all of them have bowl-sections in the base. Frost-cracks and Tear-outs rarely hold droppings even when aggregations of bats are present, because the droppings fall out of the chute-like base and are lost on the ground. I have only found droppings in Hazard-beams that are orientated at an angle above 70°. It may be stating the blindingly obvious, but droppings are more likely to be present in maternity tree-roosts, far less likely to be present in tree-roosts occupied by individuals, and less still in hibernation tree-roosts.

AUDIBLE SQUEAKING I have heard audible squeaking from roosts occupied by noctules (the species most often cited) and also from Daubenton’s bats Myotis daubentonii, the latter however only squeak in the hour before emergence. I have never heard such squeaking from maternity colonies of Natterer's bats Myotis nattereri or brown long-eared bats. __________________________________________________________________________________________ B4 - 8

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Figure B4.3. Top left: Droppings in the entrance to a noctule Nyctalus noctula maternity roost. Top right: Droppings in the base of a brown long-eared Plecotus auritus maternity roost. Bottom, droppings in the base of a Daubenton's bat Myotis daubentonii roost.

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and even ducklings may give the unwary bat surveyor a false-alarm (to his eternal shame), and (even after years of inspecting trees) the noise of bats in a tree is to my ear identical to that of starling Sturnus vulgaris and jackdaw Corvus monedula chicks, so similar in fact that I have for some time wondered whether noctules have developed the habit as a defence mechanism by which to discourage starlings and jackdaws from entering their roosts. Step (1946) cites Oldham (pers. comm.) as comparing the ‘tchek-tchek’ cry of the lesser horseshoe bat Rhinolophus hipposideros to the alarm-note of the great spotted woodpecker Dendrocopos major. As lesser horseshoe bats don’t roost in trees, one has to wonder what purpose that would serve, and it does cast doubt on my hypothesis re: noctules Nyctalus noctula, hey-ho; nothing is ever straightforward…

FLIES BUZZING AROUND A PRF Several species of saproxylic flies (Diptera) live in tree holes. Some hoverflies (Syrphidae) hibernate in them; others remain active all winter in humid hollows. Although flies do buzz around bat-droppings upon occasion, that isn't universally true and I have never perceived them as an indicative field-sign, indeed I have never perceived them at all without having been in a position in the tree where I could see bat-droppings. Even then I have never found flies in such abundance that they were present in any photograph unless I specifically wanted a shot for identification (and then it wasn't easy). Aggregations of buzzing flies are more often associated with squirrel dens, abandoned birdsnests with dead fledglings or smashed eggs and just mucky damp wet-rot. In addition, arboreal species of mosquitos such as Anopheles plumbeus and Aedes geniculatus are well known occupiers of rot-holes, as are other Diptera (Morris & Perring 1974), none of which are associated with bats (except potentially as prey).

DISTINCTIVE SMELL OF BATS OR AMMONIA This only applies to large roosts and even then you have to put your nose in the hole. If you can smell them, you can see the droppings from which the smell originates (and often see the bats). True, large numbers of noctules do pong (Gilbert White’s Natural History of Selborne (1789) describes the bats’ “very rancid and offensive smell”) but the closely related Leisler’s bat Nyctalus leisleri is apparently far less smelly (Barrett-Hamilton 1910) and I have recently sniffed a maternity-roost of brown long-eared bats (complete with dropping aggregation in the base) and all I could smell was tree. I do not believe this is a reliable field-sign, or indeed of any real practical use. __________________________________________________________________________________________ B4 - 10

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ACCUMULATION OF PREY DEBRIS Countless invertebrates including beetles (Coleoptera), woodlice (Oniscidea), spiders (Arachnida) and flies are born, live, love and die in tree cavities; there are always signs of insect presence in tree holes regardless of whether a bat has ever visited it. I have never encountered feeding remains in a brown long-eared tree-roost and these are the species I would most expect it from, and I can’t help but think if you were finding bat feeding remains they would be conspicuous by the associated bat-droppings.

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TREE-ROOSTING BATS - INSPECTING & ASSESSING PRF INTRODUCTION I feel honour bound to open this chapter with a warning: Where I have been unable to support elements of this text with proven science, I have endeavoured to ensure all the hypothesis, suggestions and arguments rest within common sense, and are therefore reasonable and believable. I must stress: this is not a prescribed method set out by a self-appointed hierophant. These methods are what work for me on a very general level, I’d very much like to hear if people have a method that they find consistently reliable. Now read on…

Due to multitude of often localised factors (including tree species, prevailing weather, fungal flora, habitat management etc.), it is rational to suppose that Potential Roost Features (PRF) will be a limited resource in the greater percentage of sites. It is also probable that the number of roost features in an area will have some influence on the length of time a colony of bats spend in the vicinity due to the need for predator and parasite avoidance. Furthermore, if we accept that each colony needs a minimum number of roosts (again to avoid predators and parasite build-up etc.), then is it not equally probable that this will influence the number of colonies of the same species that can be present in a given area? Common sense would suggest that the population of bats that can persist in an area will fluctuate with the number of roost sites available within their typical commuting range. For the third and final time; British tree-roosting bats do not make the features in the trees in which they roost, so if the number of roost features drops significantly colonies will have to range more widely, or abandon an area altogether. As a result, other than in years of poor recruitment, when a suitable roost feature is created (by whatever means) in, or close to, an area of optimum foraging habitat, it’s probable that it will be colonised. I am a firm believer in the old philosophy that “if you build it, they will come” (attributed to Theodore Roosevelt). What I mean is that if a tree in the right habitat, has the right PRF at the right height, it will more often be occupied by roosting bats than not. I stand by this belief. Where the right roost feature exists, it is rarer to find that it hasn’t been colonised, than to find that it has. Tree-roosts aren’t rare; good PRF are rare, but where they exist in the right habitat, roosts exist. In my experience, if you want to find tree-roosts using field-craft alone, you have to stop looking for the bats and start looking for the PRF. Furthermore, if you’re looking in a specific habitat, it pays to look for the PRF that the bat species known to exploit that habitat are known to favour overall. How the individual naturalist goes about finding PRF is a matter of personal preference. Most of the PRF I find are initially discovered on family walks. If I feel sufficiently curious I may return to test my hunches, particularly if the PRF is of a form I am particularly interested in. __________________________________________________________________________________________ B5 - 1

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But I must confess; my family walks are tailored in the hope of something interesting. In his book Finding Nests Campbell (1954) set out the following, and I have quoted him here as the words were both heart-warming and reassuring to me in the early stages of a rather lonely quest: “Finding a nest is rather like playing a hole at golf. Your drive takes you to the locality suitable for the bird, an iron shot see you in the right habitat, a nice approach carries you to the neighbourhood of the site, and your putt is the actual discovery of the nest”. Finding bat-roosts does, however, also make up a proportion of my professional workload. For this reason I have developed a structured method by which I go about performing surveys. The following text sets out all the methods I use for inspecting and assessing PRF. I would recommend the reader picks and choses what they want to suit their own ends. Don’t forget, there’s always something living in a PRF, it might not be a bat but the other beasties are no better understood, so record everything of interest you find and send it to the County recorders for that Taxa! Happy-hunting, and please do let me know how you get on. It’s a lonely life this woodland bat obsession, and it’s always nice to hear from fellow enthusiasts.

GENERAL Lonsdale (2000) suggests that, for a basic tree hazard assessment (typically termed Visual Tree Assessment, or VTA) it is reasonable to view trees from the ground using binoculars, with the caveat that “if a ground inspection reveals potentially significant features that cannot be properly seen from a distance, it may be necessary to complete the inspection by climbing or from a hoist”. Greenaway (2001) identified the fact that the outward appearance of PRF often belies their internal conditions, which makes external assessments ineffective when determining roost presence. I have only once seen what I thought might be a dropping on the outer rim of a Hazard-beam before I performed a close inspection. While all the maternity roosts I have seen held droppings in the base, 50% (12 of 24) of the roosts occupied by individual bats I have recorded over the last year held no droppings. To put this in context, how often have any of us looked up at a bat-box and seen droppings, staining or scratch-marks that would confirm occupancy? Furthermore, how many of us would use an ultrasound detector to assess the status of a bat-box? You can waste a good deal of time with a bat-detector standing under a PRF which actually has no potential whatsoever. Ultimately if you want to find a tree roost without radiotracking, you’re going to have to get up there and look in the hole. Campbell knew this about birds when he wrote Finding Nests in 1953, and he devoted 12 of the overall 14 pages of the chapter in his book that deals with nest inspection to arboreal climbing, and this is a guy who __________________________________________________________________________________________ B5 - 2

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didn’t use a rope! I refer back to Campbell (1953) again, who pointed out in relation to the chaffinch Fringilla coelebs, that the more chaffinch nests you find, the better your mental picture of the ‘ideal’ chaffinch nest; “after a time your eye is drawn to the likely sites in any habitat”. The same is true of for tree-roosts; after a while your eye is drawn to certain tree shapes, and the logical place for the PRF to occur on that particular tree without even thinking about it, but you have to keep looking in the PRF to drum this ‘jizz’ into your subconscious.

LEGAL CONSIDERATIONS In the British Isles all species of bats and their roosts are protected against under the Wildlife & Countryside Act 1981 (& as amended) and The Conservation of Habitats and Species Regulations 2010, which implements the provisions of EC Directive 92/43 (“The Habitats Directive”). Common dormice Muscardinus avellanarius, pine marten Martes martes and red squirrels Sciurus vulgaris are also protected under the Wildlife & Countryside Act 1981 (& as amended), with the former receiving additional protection under The Conservation of Habitats and Species Regulations 2010. Finally, the nests of the 30 species of bird that use PRF are also protected under the Wildlife & Countryside Act 1981 (& as amended), with barn owl Tyto alba and crested tit Lophophanes cristatus listed on Schedule 1, making it an offence to disturb the birds while they are on the nest. I would hope anyone searching for tree-roosts would apply common sense, assume something will be living in the hole and, even if it isn’t a bat, proceed with due care to ensure the inspection results in only a minor disturbance effect and no breach in legislation.

If the PRF cannot be reached without potential damage, then inspection should not be performed. If surveyors are not licensed to disturb bats by the relevant Statutory Body, inspection should stop at the entrance.

HEALTH & SAFETY Caution: as well as bats, smaller birds and mice etc. tree cavities are also used by nesting owls, bees and wasps (Hymenoptera) and hornets Vespa crabro. Tawny owl Strix aluco nest in hollow trees in parkland (Simms 1971) and, in particular, appear to favour the interior of decayed trunks (Thomson & Rankin 1923), but may also take __________________________________________________________________________________________ B5 - 3

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shelter behind ivy (Sparks & Soper 1970). A female tawny owl on a nest will attack repeatedly if disturbed and will not cease until the threat is well out of range. There is at least one recorded instance of an experienced ornithologist having been blinded in a tawny owl attack. If you’re getting into the canopy you should also be aware that long-eared owls Asio otus nest within old squirrel Sciurus spp. dreys and display a comparable aggression to the tawny owl when defending young (Thomson & Rankin 1923). Bees and wasps will readily swarm and sting and hornets will also drop and sting the unwary surveyor, the effects of which can cause very dangerous allergic reactions.

INSPECTION OBJECTIVE The objective during PRF inspections is to make a comprehensive examination and record of the PRF. The purpose of the inspection is to:  determine whether or not bats are present; and  if bats are not present, whether the PRF is nonetheless suitable; and if so  for which species, when and for what purpose. The inspection should be performed with sufficient sensitivity to avoid:  disturbing bats (or birds etc.) if they are present;  damaging the PRF or any birds nest etc.; or  in any way altering the conditions (such as by snapping an overhanging branch or removing debris, including mud deposited during nest-making by nuthatch Sitta europaea).

INSPECTION EQUIPMENT To adequately perform the PRF inspection the following equipment will be needed:  Mechanical Elevating Working Platform (MEWP), ladder and/or arboreal climbing equipment;  Fibre-optic endoscope;  Small torch;  Long-handled cocktail spoon for the retrieval of droppings (optional);  Specimen tubes for droppings;  Digital camera;  Diameter tape-measure;  Standard tape-measure;  Compass;  Clinometer; and  Egg-carton sections or similar for dropping traps (optional). Barrett-Hamilton (1910) suggests the “insertion of a flexible stick [which] sometimes dislodges a surprising number of bats”, but I’m pretty confident that would be in breach of legislation! __________________________________________________________________________________________ B5 - 4

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In most woodlands the terrain and the spacing of the trees themselves precludes the use of a Mobile Elevating Work Platform (MEWP). Furthermore, past experience has shown that it is very often impossible to manoeuvre the cage into sufficient proximity with the PRF without the surveyor being in breach of Health & Safety best-practice by hanging over the edge. However, wherever possible it is advisable to work from a MEWP to inspect PRF as by their very nature, they comprise weakened areas in the trees structure. Where access to a PRF is impossible due to safety restrictions, I have found that one surveyor equipped with a 2-million candle-power torch and another with a good pair of binoculars can, from the ground at dusk, often perform a sufficient assessment to give a yes or no answer as to whether or not a PRF has any potential. The method is most effective with the torch being shone directly over the observers shoulder, but it may be necessary to alter angles and both surveyors get up into an adjacent tree or structure to get a better angle. It is surprising just how effective this method can be once a team gets the hang of it. However, if bats are present this method results in a high level of disturbance, so it should only be used where the tree is to come down, and the team is licenced.

Endoscopes A surveyor proficient in the use of an endoscope is highly unlikely to any more than a low level momentary disturbance. The technique is not noisy and done well results in minimal disruption, typically over within one minute. I have a Ridgid C300 with an inbuilt camera; I can inspect and photograph anything I find within 20 seconds, and then identify it away from the roost. I have never perceived abandonment due to endoscope survey activity. Furthermore, I would argue that the only way you get good at something is by doing it, and if you have a batlicence you really should be out there practicing until you're competent to confidently assess tree-roosts, otherwise how are you to know what the inside of a tree looks like and where the bats will be?

INSPECTION METHOD Much (if not all) of the following text is common sense, but to emphasise which parts of the inspection are most important I have underlined specific aspects. This is because I wish to save you the frustration of my own past mistakes. Inspection should begin from the ground. When a ladder is being used try to rest it well below the PRF in the first instance so any droppings that may be present are not disturbed, it can always be moved again once this stage is complete. If you’re climbing then wherever possible approach from the opposite side until you can swap sides and descend __________________________________________________________________________________________ B5 - 5

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to the PRF with the minimum disturbance. Begin looking without touching. Check the surface of the tree for droppings below the PRF and on either side. If the tree is of a species and age with rough bark, such as oak Quercus spp., ash Fraxinus excelsior, sweet chestnut Castanea sativa or poplar Populus spp., look carefully at any fissures in the bark surface, droppings can sometimes be present even in winter. In the case of lifting bark, look at bark lips below the break for trapped droppings. Regardless of the form of the PRF, it is vital that you work inward, downward and finally upwards to avoid disturbing material that may fall down and obscure evidence in the bottom of the cavity. British bats are often found asleep in summer positions where they are exposed to moderate or even bright light (Barrett-Hamilton 1910), so don’t be so focussed on the dark apex that you fail to look on either side of the entrance.

Inspecting Decay PRF With a hollow PRF such as a woodpecker hole, knot-hole etc., start by shining the torch in and look at the interior edge of the rim and the interior walls to inspect for droppings and assess the overall condition. If the entrance is discontinuous and you can perform the entire inspection without the use of a torch or endoscope then it can be discounted as a potential day-roost. If however, the entrance opens into a darkened void, then the PRF has potential. Assuming the entrance rises into a dark hollow, then the key attributes from here on are whether the internal walls are dry (although some that are wet in winter are bone dry in summer), clean (as opposed to dusty and cobwebbed), firm (as opposed to corky or spongy) and smooth (as opposed to rough with loose sinew and dead wood tissue). All the time you should be quiet so that if bats are there you don’t disturb them. In the vast number of cases you won’t find any evidence of occupation other than the bat itself. However, if you do find any droppings try to lift them off with the cocktail spoon and drop them in a sample tube for DNA analysis. Warwick University offers this service (http://www2.warwick.ac.uk/fac/sci/lifesci/research/bats/). If the PRF descends into a bowl-section then work downwards very carefully. This will usually need an endoscope. Keep looking for droppings on the internal walls. When you get to the base look for evidence of occupation by other animals; birds nest, leaves brought in potentially by wood-mice Apodemus sylvaticus, dormouse Muscardinus avellanarius nest etc. Then look on the top of the pile for any discernible bat droppings: this is often frustrating because you can’t get them out and just have to make a judgement on whether they are bat droppings or not by eye. __________________________________________________________________________________________ B5 - 6

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Finally, come back to the entrance and work upward very slowly. Again you’re looking at the overall condition of the interior and whether it looks inhabited. This may sound strange but it helps to think along the lines of - is this hole clean, dry and smooth enough that would I put my head up it to look around if I could? If the answer is yes then you’re on to something. Photos B5.1 and B5.2 show the interior appearance of two cavities inhabited by bats, Photos B5.3 and B5.4 show cavities definitely not inhabited by bats.

Photo B5.1. Daubenton’s bat Myotis daubentonii maternity roost. Note the smooth dry interior, entirely lacking in dust, debris or invertebrates – the 22 bats had just left when this was taken.

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Photo B5.2. Cross-section of Tear-out on a sycamore Acer pseudoplatanus stem that had held two Daubenton’s bats Myotis daubentonii males. Note the smooth surface, typical of inhabited cavities. __________________________________________________________________________________________ B5 - 8

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Photo B5.3. Looking up into an unoccupied cavity more or less identical to the one in Photo B5.1 above, and only 6 m away from it. Note the rough surface and debris on the interior wall.

Photo B5.4. An obviously unoccupied rot-hole in a beech Fagus sylvatica. __________________________________________________________________________________________ B5 - 9

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In the case of hollow PRF the next question is; is the cavity one individual tube, or is it chambered? Beware: it is very easy to overlook chambers for which the opening is just above the main entrance and opens toward the surveyor (see Figure B5.1). Then is the PRF sealed, or a tube? Turn off the endoscope light and look – can you see light? Then there is another entrance hidden further up the stem or branch and this will also need inspection.

Figure B5.1. An example of a chambered Tear-out in a sycamore Acer pseudoplatanus in which two male Daubenton’s bats Myotis daubentonii regularly roosted in the hidden cavity on the left, but never in the visible cavity despite its superficial suitability.

Finally inspect the accessible areas carefully. The rule of thumb here is that if you have to withdraw the endoscope and clean the end regularly to remove sludge, moist dust or cobwebs from the end, then it is unlikely there are bats present today. If you’re knocking down little congregations of woodlice, or if the cavity is dusty with fungal hyphae visible then it is unlikely there are bats present today. No bats today does not however, mean there will be no bats tomorrow. If the PRF is clean and dry, bear in mind that any bats present will be head down and often eyes shut, as such you’re looking for little brown fluffy blob, with two little black knobbles (all you can see of the elbow), one on either side. If only one bat is present this may be very obvious, if more than one bat is present it can be very difficult to pick them out. However, __________________________________________________________________________________________ B5 - 10

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they’ll often be squashed tightly into the cavity apex. Don’t try to identify them just make a quick head count and withdraw. This part of the survey is now complete. If the PRF is higher than your endoscope then you have to judge probability on internal condition. If you judge the PRF has any potential to hold roosting bats then ultrasound survey will be necessary. However, In the case of PRF with a bowl-section it may be helpful to insert an egg-carton section as a dropping trap to aid in identification. A head count and DNA analysis is invariably more cost-effective and, particularly in the case of Myotids, a more conclusive method of identification.

Inspecting Damage PRF The Damage PRF that are longitudinal in nature can be complex and their inspection will depend upon the orientation; vertical or horizontal. While I accept that this contradict the advice I gave in relation to Decay PRF (i.e. work up from the bottom), I find it far easier to assess vertical splits with an endoscope from the top working down-ward. Where the top of the crack/split extends up into a hollow stem or limb this should be inspected in the same way as a woodpecker-hole or rot-hollow but do not be seduced into discounting the lower areas of the split if the hollow is vacant or unsuitable, a full inspection should always be made. Unfortunately, the important areas are those which are least accessible, typically behind lips of callous growth on either side, which may extend under bark. These can be particularly fiddly to inspect and it is often necessary to approach from much higher up on a very shallow angle in order to work the tip of the endoscope adequately in and behind. However, once a satisfactory view is achieved this can be followed all the way down. Do not however be surprised if the crevice extends round remaining heart-wood into a depth greater than can be inspected with a torch or an endoscope, where this happens it will be necessary to perform ultrasound survey. Pay particular attention to areas where bark still bridges the crack/split and/or callous growth has partially repaired damage. Inspection of a horizontal split is often most practical working from the centre outward. Even more or less horizontal branch cracks will still have an upper and a lower end. In all cases the upper end of the crack is that which in which bats will roost as any rain ingress would flow downward waterlogging the base of the split. A split that is suitable for occupation by dayroosting bats will extend upward into a dark crevice, in older cavities occlusion around the edges may form an envelope of callous providing a dark ‘pocket’ in which bats may hide. Alternatively it may be that the split is as a result of decay (for whatever reason) in the Heartwood and the crevice extends up into a deep and dark hollow. In any case the same __________________________________________________________________________________________ B5 - 11

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inspection principals will apply to the potential roost ‘pocket’ or hollow in a longitudinal split as would in a Woodpecker-hole or rot-hollow. As always, you’re looking for a dark, clean and dry internal environment in which you would be prepared to spend the night yourself if you were small enough. If the internal areas are mucky, dusty, damp and/or full of inverts such as slugs, snails and woodlice then the cavity is not occupied. But remember, vertical cracks/splits are typically extensive so look for the anomaly; if you suddenly find a nice dry clean pocket in an otherwise unsuitable split, then something has to be keeping it clean. Inspection of a Transverse-crack will depend upon the situation, as the primary consideration is one of safety. Very often the feature will be at the base of an unstable stem which may be hung-up above. It is up to the individual how and indeed if, they proceed. The principals, however, that apply to Woodpecker-holes and rot-hollows also apply to Transverse-cracks; if you can perform the entire inspection and see all the internal areas without using a torch or endoscope then the cavity will not hold a day-roost of any bat species. For loose-bark to comprise a Potential Roost Feature it must, as with all other PRF’s extend into a dark, and secure internal space. As such, depending on what caused the initial failure in the bark, and how the bark has subsequently lifted, the internal areas may be similar to the ‘pocket’ or crevice of a longitudinal split.

Inspection of Association PRF Aside of the difficulty in accessing some Unions, their inspection is very straightforward, and very often achievable with a torch alone; simply look up. For ivy to provide an environment suitable for occupation by roosting bats it has to have attained significant age. Typically the stems should be a minimum of 50 mm diameter (ideally some even larger) and form a network, intertwining and crossing up the stem and into the crown. This network will have sections that have therefore formed pockets into which bats sidle into or crawl up under to rest against the bark of the mature tree. In the vast percentage of cases these stems will lack foliage. This text has been revised in light of information from Dr. Geoff Billington. Originally I had suggested ivy was easily inspected by working from the ground upward despite the high number of PRF’s that it may encompass. This was my genuine belief but I have subsequently learnt that barbastelle Barbastella barbastellus use ivy Hedera helix from 4 m up to 18 m (Natural England 2012), so I have now revised my approach; if the ivy is over 50 cm and visual assessment suggests it is suitable to conceal a bat, and the tree is located or on the edge of ancient semi-natural woodland, the only practical assessment tool will be a series of dawnreturn surveys. __________________________________________________________________________________________ B5 - 12

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PRF Cataloguing Regardless of the form of the PRF I record the features to an established criteria first defined by Sedgeley & O’Donnell (1999), then refined by Ruczyński & Bogdanowicz (2005), and finally altered to suit my agenda. The criteria comprise: 1. Date; 2. Ordnance Survey grid reference; 3. Site name; 4. Tree species; 5. Habitat (see Table B3.2); 6. Tree alive or dead; 7. PRF location: stem or limb; 8. PRF type; 9. Entrance facing (compass direction); 10. Tree height (clinometer reading) 11. Diameter at Breast Height (DBH - Diameter tape reading) 12. PRF height (Clinometer reading); 13. Diameter at PRF height (DPH - Diameter tape reading); 14. PRF entrance height & width; 15. Internal height, width & depth; 16. Internal conditions (see Table B3.2); 17. Comments; and 18. Photographs This list of features may appear onerous but experience has shown that two surveyors working together can rattle them off very quickly. Reference to Table B5.1 will show that the criteria are divided between the Groundsman and the Climber. I would however urge that one person is given overall responsibility for ensuring the form is completed. This is logically the Groundsman. The most effective system is for the Groundsman to direct the climber and also act as the scribe. The Groundsman has responsibility for ensuring the forms are completed in their entirety and filed in an ordered fashion in the field. They should therefore be a strong personality with a powerful voice who can bark each criterion in order and then fill them in. The Groundsman completes all his section whilst the climber ascends to make the inspection. When the Climber is in place the Groundsman reads each criterion in turn loudly, and as the Climber provides the answers the Groundsman completes the inspection sheet. By this method the whole job can be performed by one Groundsman and two absolute novices with minimal instruction. N.B. Where arboreal climbing is required, a minimum of two CS38 certified climbers are in any case required to satisfy Health & Safety best practice, one of whom must be on the ground to act as grounds-man/rescue. __________________________________________________________________________________________ B5 - 13

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Table B5.1. PRF recording form DATE GRID REF SITE TREE SPECIES GROUNDSMAN

HABITAT (see form base) TREE ALIVE/DEAD PRF STEM/LIMB PRF FORM ENTRANCE FACING TREE HEIGHT DBH PRF HEIGHT DPH Height ENTRANCE Width Height INTERNAL DIMENSIONS

Width

CLIMBER

Depth SUBSTRATE HUMIDITY APEX SHAPE INTERNAL CONDITIONS

APEX CONDITION COMPETITORS

Smooth Dry Dome Sludge

Bobbly Damp Spire Unknown

Rough Wet Wedge

Dusty/debris Flooded Chambered

Dry

Damp

Wet

Sludge

Slugs

Woodlice Mice misc

Bees etc.

Spiders

Squirrels

Birds

Dormice

COMMENTS

PHOTOS

Habitats: 1. Woodland: wet/dry broadleaved or mixed/coniferous – distance from woodland edge and riparian habitat; 2. Riparian – distance from woodland; 3. Hedgerow: continuous or discontinuous – distance from woodland; or 4. Isolated __________________________________________________________________________________________ B5 - 14

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While most of the recording is very straightforward and the process will be identical from tree to tree, the recording of the entrance and internal dimensions often throws junior surveyors. I have provided the following passages to soothe trouble minds. Entrance hole dimensions First, bear in mind that you have defined the type of PRF you are recording, so if you propose to analyse your data you will be analysing the types together and not a mixed bag of different types. When recording PRF you should record all the internal dimensions from the access-hole. The internal height is the distance from the top of the entrance hole outer rim to the top of the void (see Figure B5.2 - a), the width is the distance from the outer entrance lip to the back of the void on a horizontal line (see Figure B5.2 - b), and the depth is the distance from the bottom of the entrance outer rim to the bottom of the void (see Figure B5.2 - c).

Figure B5.2. Measuring internal dimensions of PRF. Confusion appears to arise from the distinction of exactly which point defines the entrance on individual PRF, and whether or not the location in which bats can be predicted to roost is a single clearly defined void. For example; Frost-cracks have what at first sight appears to be a __________________________________________________________________________________________ B5 - 15

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tall and narrow entrance. However, although the crack might appear to be the entrance, in fact the entrance is technically the point at the apex where the crack stops and the darkened void begins. This is true, but this is a point that can be drawn-out at the analysis stage as you will still have the relevant measurement on the form, only it's filed under internal width (and obviously the internal void has not depth so this is recorded as N/A). If the internal width has is obviously uneven; on the horizontal the front to back is distinctly different from side to side (very often the case with Hazard-beams where inside the split the internal top-to-bottom width of the pocket is less than the horizontal width) then just say so on the form (i.e. top-to-bottom: 4 cm, side-to-side: 12 cm). I hope this clarifies the situation, but if you're still confused then email me and I'll explain.

TIMING General Unlike roosts in houses, churches, caves and tunnels which, on the whole, tend to be occupied by bats during set periods of the year and for specific purposes, trees are occupied year round but different cavities are used for different purposes by different species, so a cavity that did not hold bats in high summer when nesting birds were present may do in winter, and vice versa. In addition some species (such as noctules Nyctalus noctula, Natterer’s bat Myotis nattereri, barbastelle and to a lesser extent pipistrelles Pipistrellus spp.) are nomadic (Kronwitter 1988, Smith & Racey 2005) using a high number of roosts, but occupying each roost for only a very short period of time. While it might appear sensible to target presence/absence surveys to the time of year when population densities are at their highest, and it might be logical to suppose that with all species of bats this period is the autumn; when young disperse and there are therefore greatest numbers of bats on the wing (before the inevitable winter mortalities of the sick, old, inexperienced and just plain unlucky), it would in fact appear that different species occupy trees at different times and in widely varying numbers. In 2001 a study looking at barbastelle ecology in Somerset (Natural England 2012) found that in July, whilst the colony foraged outside the woodland, they roosted exclusively within one woodland; Horner Woods. When the study was continued in September five nights trapping drew a complete blank, and although barbastelles were again present in October, radiotracking found that they were no longer exclusively using Horner Woods, but also roosts in three other woods in the locality. Furthermore, of the total 10 trees the bats were found to be occupying, only one had previously been recorded, so although they returned to the same wood, they didn't occupy the same trees. A similar situation was again recorded in 2002, this time in Pengelli Woods, Pembrokeshire, where trapping in September failed to record a __________________________________________________________________________________________ B5 - 16

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single barbastelle, despite the fact the species was successfully trapped in the summer months (Natural England 2012). An autumn survey visit would therefore be likely to draw a blank for barbastelles. A study performed in Czechoslovakia from 1978 to 1987 by Červený & Bürger (1989) found that Daubenton’s bats Myotis daubentonii, noctules and Leisler’s bats Nyctalus leisleri occupying tree-roosts exhibited variations in the date of arrival; Daubenton’s bats and Leisler’s bats arriving in April, but noctules arriving a month later. All, however, left around mid-September. An autumn and winter visit would therefore have been likely to have drawn a blank for Daubenton's bats, Leisler's bats and noctules. I have two winter roosts occupied by noctules that are not occupied in any other season, by either the noctules or any other species. A spring or summer visit to these trees would draw a blank for Bechstein's bats. In their long-term study of Bechstein’s bats Myotis bechsteinii Dietz & Pir (2011) found great tits Parus major and starlings Sturnus vulgaris nesting in roost sites during May and June, that were subsequently occupied by maternity colonies and individual males at the full range of heights. They considered that, as some PRF encompass a set of characteristics favourable to several species of birds and mammals; the breeding time of different animal species is temporally adjusted to avoid inter-specific competition. Whatever the reason, an early summer visit to these trees would be likely to draw a blank for the bats. The complexities don't end there as tree-roosting species are nomadic, moving between a number of trees within their home range. For example Dietz & Pir (2011) recorded 57 treeroosts occupied by female Bechstein's bats, and seven roosts occupied by males and found the maternity colonies transient with duration of occupancy increasing during pregnancy; averages:- pregnancy: 1.5 days, lactation: 3.3 days and post-lactation 4.8 days (Dietz & Pir 2011). Furthermore, although the males were less transient and this decreased over the course of the active year, they still moved roosts on average every 6.6 days (ibid). So when is the best time to inspect PRF and how often should they be inspected? Well, the truth is we really don't know as no studies have been performed that might give a hint as to what the optimum season and intensity of such a survey might be. The following sections are provided as a repository for development as more information becomes available, in the hope that they will illicit information from readers. I have also included some very basic guidelines that I follow in my own work.

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fluctuations are small (Harris & Harris 1991). Valleys may certainly yield rewards, even if it isn't what you were expecting; that ideal low-level Natterer’s/brown long-eared bat Plecotus auritus PRF that you kept checking with a nil result in summer, can turn out to have a noctule in it come winter providing there is a sufficient drop for them to pick up speed (i.e. a tree above a railway-cutting, in a beech hangar, or on a ravine side). Mitchell & Kirby (1989) cite Steele (1975) who suggested “several bat species roost or hibernate in hollow trees which are liable to be removed under commercial forest management…” I may be reading too much into this but it’s interesting that Mr. Steele says “roost OR hibernate in hollow trees…” I’m beginning to wonder whether pipistrelles don’t really use trees much in the summer, but mate in them in the autumn, and hibernate in them in the winter; does Mr. Steele know something we don’t!?! I couldn’t get his paper so if you know him, you might ask… My approach I map PRF in winter. However, unless the tree is; in a perilous state or position, scheduled to be felled and/or subject to a planning application I do not perform internal inspections in the period December through March.

This restriction does not however prevent a close inspection of the external features of a PRF, and this may yield valuable information. Figure B5.3 on the following page shows droppings found in tree-roosts in winter. However, hibernation roosts may not ever hold any evidence of occupation save the bats themselves.

Spring Červený & Bürger (1989) made a good deal of the discovery of a male bat with two young females in a tree-roost in April suggesting that the species may breed early in the year as well as in the more normal autumn period. My approach I begin my inspections in April and have found small roosts holding individual barbastelle, Natterer's bats and brown long-eared bats at this time (and I mean individual, not low numbers, single bats). I don't know whether they were males (my endoscope isn't that good), but one wonders whether mating may play a part.

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Figure B5.3. Top left: Characteristic furry mould on top of old brown long-eared bat Plecotus auritus droppings. Bird droppings don't appear to develop this mould and it is distinctive in the early winter (December through January). Top right: not all white droppings are bird droppings; these are brown long-eared bat so it pays to look closely. Bottom: Natterer's bat Myotis nattereri droppings caught in a spider's-web. Webs are the bat surveyors friend, they trap the droppings but also appear to preserve them intact for long periods (if we could synthesise webbing it would be a superb survey tool).

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Summer Simms (1971) found that most hole-nesting birds, not just summer migrants, desert woodlands after the close of the breeding season. In their study, Červený & Bürger (1989) found the highest number of tree-roosts occupied by bats in July, when the large maternity colonies of Daubenton’s bats began to break up as the young began flying. They suggested that, as this period is also the end of the bird-nesting season (which does tie in with our British timings), this might be the result of reduced competition with hole-nesting birds, and in particular starlings, making reference to the paper: Mason C & Stebbings R 1972. Noctules (Nyctalus noctula) and starling (Sturnus vulgaris) competing for roost holes J. Zool. Lond 166: 467, if anyone out there has a copy of this I’d love to see it so it can be added in. Dietz & Pir (2011) found that a single Bechstein's bat maternity ‘colony’ occupied two or more tree holes during the pregnancy and lactation period, so a minimum of two PRF were needed every day. However, this isn’t the end of it; after weaning the colony may be divided between three or more PRF, all of which were nearby (unfortunately they didn’t define ‘nearby’, so if anyone reading this is lucky enough to meet them they might ask). This situation may be repeated for other species, which would suggest that targeting survey effort toward the weaning period would be sensible, as more trees will be occupied so you might strike lucky and find the maximum number of roosts with the minimum effort. My approach I try to check PRF in June, July and August but where I'm restricted to only one visit I go for late July (see the Autumn text re: swarming for why August is not ideal).

Autumn Autumn appears to be a time of change. In the August to November period bats of several species may be encountered in mating swarms in the vicinity of hibernation cave and tunnel entrances (Stebbings et al. 2005). Swarms typically consist of several species but, occasionally, may only consist of one species. Natterer's bats are generally the most common visitors to swarming sites, although Daubenton’s bats are also common and seem to peak their swarming activity slightly earlier in the season (Altringham 2003). Brandt’s bat Myotis brandtii and brown long-eared bats are also present in smaller numbers throughout England whilst Bechstein’s bat and barbastelle can be found swarming in the south (Altringham 2003). Swarming is most conspicuous in mid-August to mid-September (Parsons et al. 2003a, Glover & Altringham 2008). __________________________________________________________________________________________ B5 - 20

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Swarming behaviour would suggest that tree-roosts would be deserted by the greater percentage of tree-roosting bats from mid-August onwards, just as Leisler's bats, noctules, Nathusius’ pipistrelles Pipistrellus nathusii, common pipistrelles Pipistrellus pipistrellus and soprano pipistrelles Pipistrellus pygmaeus are beginning to look for mating sites. Late in the summer, as nursery colonies fragment, the male pipistrelles appear to advertise their presence to females with a song flight from such mating roosts (Altringham 2003). They fly backwards and forwards in the vicinity of their roost, emitting a distinctive call every few seconds (Altringham 2003). Continuing with Professor Altringham; migration between summer and winter quarters is most common in tree-roosting bats because trees offer poor insulation against intense cold but males may remain in the summer territory over the winter months (Altringham 2011). Furthermore, male Nathusius’ pipistrelles, Leisler’s bats and noctules appear to set up mating roosts on these migration routes (often on river corridors) which are followed year on year (Altringham 2011). My train of thought was hijacked one evening by Green (2010) who says of mushrooms “the soft, fleshy annual mushrooms usually appear from the end of summer through the autumn and into early winter…” then goes on to say “…the insects, often flies, are emerging from the fruit-bodies at the time when the bulk of other insects are finished for the year. Therefore they provide a succession of food, especially for birds, bats and small rodents, at a period when other insect food is declining.” We know that dormice Muscardinus avellanarius bulk up on hazel prior to hibernation, why wouldn't bats breed and bulk at the same time…? I have this hypothesis that in the autumn mating bats occupy PRF in close proximity to aggregations of fruiting mushrooms (more specifically the abundance of flies which egg-lay in mushrooms) the abundance of which varies in location from one year to the next. I just thought I’d put it in here in case someone else proves it; I can then say “I told you so…” and look really sagely.

It is as yet unknown whether the ‘quality’ of the roost has any bearing upon mating success or whether there is any hierarchy in the features occupied; i.e. do the strongest bats occupy the best holes, and do they re-occupy them year on year? Schober & Grimmberger (1987) suggest noctule and Nathusius’ pipistrelle males often retain their mating territories for several years, and Altringham (2011) suggests that common pipistrelle males also defend preferred mating roosts for up to five successive years. I've never seen a Leisler's bat or Nathusius’ pipistrelle tree-roost so cannot even begin to discuss their attributes. I have however found noctule lekking-roosts, occupied by individual males during the day, but with no females present; both were Woodpecker-holes. Schober & Grimmberger (1987) suggest that noctule and Nathusius’ pipistrelle males live alone and accumulate a harem of up to ten females. I'm confused; if they live alone then we're looking for an individual, if they accumulate a harem surely they aren't on their own? Finally, having several times found song-flying common and soprano pipistrelles at night __________________________________________________________________________________________ B5 - 21

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with an ultrasound detector, I have failed to relocate them a dawn by the same method and searched for the roost in vain the following day. Whether they were exposed features only used for night-roosting or, whether the bats had retired early to inconspicuous atypical PRF, I cannot say. My approach I try to get autumn visits in both late August and early September. If I've only got one visit then I go for the end of August.

PRF ASSESSMENT Assessment objective Where bats are recorded within the cavity on the initial visit or where certain evidence can be collected for analysis (such as droppings for DNA analysis) the survey may be considered fortuitous and this section is consequently redundant. However, in the vast majority of cases bats will not be present on the first visit, and the objective is to perform a reasoned assessment of:  Whether or not the PRF is suitable to hold roosting bats at all; and if so  Which species might be present;  In what numbers;  For what purpose; and  When. PRF Assessment When assessing the suitability of a particular PRF to hold bats, a sliding scale of potentiality from low, through moderate, and up into high is subjective between surveyors and unhelpful to any third party reading a report. I always think that where low/medium/high are used they should be quantified by a percentage score, for example low: 0-33%, medium 34-66% and high 67-100%. Where this is impossible, then the use of low, medium and high appears to me to be nonsense. Aside of anything else, a PRF that is of low potential to one bat species is often of high potential to another.

The situation is simple; either the PRF is suitable to hold roosting bats or it isn’t and, if it is suitable, then the surveyor should have sufficient knowledge of the tree-roosting ecology of bats to put forward a reasoned hypothesis as to which species might be present, when, and for

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what purpose in order that the survey can then target that period to search for the specific species and demonstrate their status to within reasonable doubt. Bat Tree Habitat Key Using the information you recorded on the PRF recording form, you can process unoccupied (but suitable) PRF through the Bat Tree Habitat Key provided at Chapter B5 which is based on the literature review provided in Chapter B1. Bat Tree Habitat Key will provide a reasoned prediction as to:  WHICH bat species might occupy a particular Roost Feature; in  EACH habitat; and for  WHAT purpose; thereby allowing survey to be targeted  WHEN the species is most likely to be present.

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TREE-ROOSTING BATS - BAT TREE HABITAT KEY INTRODUCTION Rackham (2003) said “ecology is not a hard science like physics, with well-defined, highly quantitative laws to which there are no exceptions”. There will be exceptions to this key. However, I take heart from Campbell (1953) who pointed out that although at the time accounts of freak bird nesting sites in newspapers were an annual occurrence and (whilst accepting that there were regional variations) the majority of bird species showed recognisable preferences for certain types of sites. Also in the world of ornithology, Perrins (1979), speaking of the titmice, set out that "over long periods of time natural selection has favoured those individuals of a species, which have evolved ways of life which differ from those of other species; in this way, interspecific competition has been avoided". I don't believe the situation is any different for bats. Yes there are atypical roosts (as James Thurber mused; "there is no exception to the rule, that every rule has an exception"), but there are far more that conform to the stereotypes. The number of variables may be wide, but by recording PRF to a standard format we should soon build a clear picture of which are the most important. I'm not suggesting that the characteristics defined represent a comprehensive list (I'm sure the location of the tree above or below the winter sun-line will be an important characteristic in the occurrence of hibernation sites), and some may be dropped along the way, but a journey of 1,000 miles starts with a single step, and will help if we're all stepping in the same direction. It will be noted that the PRF nomenclature used in the Key does not follow forestry and arboricultural nomenclature used in the main body of text. This is because the studies and accounts from which the key is constructed (Provided at Chapter B1) do not use forestry and arboricultural nomenclature. However, to avoid confusion, the PRF are listed below with their placing in the Key.

Decay PRF Key category       

Woodpecker holes – woodpecker-hollows; Knot-holes – Rot-hollows; Flush-cuts – Rot-hollows; Tear-outs – Rot-hollows; Double-leaders – Rot-hollows; Wounds & Cankers – Rot-hollows; and Butt rots – Rot-hollows.

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Damage PRF Key category        

Hazard-beams – Longitudinal split & Crevice; Frost-cracks – Rot-hollow, Longitudinal split & Crevice; Subsidence, Shearing & helical spits – Longitudinal split & Crevice; Lightning-strikes – Longitudinal split & Crevice; Impact-shatters – Longitudinal split & Crevice; Desiccation-fissures – Longitudinal split & Crevice; Transverse-snaps – Transverse crack; and Lifting bark – Loose bark.

Association PRF Key category Unions – Crevice; and Ivy – Ivy.

KEY GLOSSARY PRF – Potential roost feature. Pm – Primary maternity: roost feature preferentially selected by maternity colonies of a particular species. Sm – Secondary maternity: roost feature occasionally occupied by maternity colonies of a particular species. T – Transition roost occupied by low numbers of bats (mixed sex) or individual males of a particular species. H – Hibernation roost. ? – Where literature review found generalisation and/or suggestion (in grey literature alone) the potential species present are set out in italics preceded with a question-mark. No data – Where literature review found no published account indicating usage or avoidance of a particular PRF by any bat species.

__________________________________________________________________________________________ B6 - 2

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

GENERAL KEY 1 Host tree located within woodland 1 Host tree not located in woodland 2 Host tree located on the bank or within 10 m of the bank of a river, lake or large pond

Key A (Page 3) 2

Key B (Page 34) 2 Host tree greater than 10 m from a river, lake or large pond 3 3 Host tree located on or within 10 m of a hedgerow, tree-line or other linear feature such as a terrace of houses, or parkland trees between which a line can be navigated which is never less than 10 m from canopy to canopy Key C (Page 60) 3 Host tree isolated within the landscape Key D (Page 71) KEY A Woodland trees: Broadleaved or coniferous tree in woodland or on woodland edge. 1 Woodland s of > 2 ha in surface area and/or smaller woodlands which are connected to woodland in the wider landscape via a network of well-structured hedgerows which are themselves:  1 m tall;  with no gaps > 20 m in length; and  Subject to negligible (or no) artificial lighting.  N.B. Typically woodlands in an undisturbed pastoral setting 2 1 Woodlands of < 2 ha which are isolated in the landscape or connected to other woodlands by hedges which are themselves:  < 1 m tall; and/or  with gaps > 20 m in length; and/or  Subject to significant artificial lighting.  N.B. Typically woodlands in an arable or urban setting 268 2 PRF above 1 m height 3 2 PRF below 1 m height 184 3 Broadleaved woodland 4 3 Coniferous / mixed woodland 109 4 Dry woodland – Oak, beech ash etc. 5 4 Wet woodland – Willow / alder carr 99 5 PRF host-tree alive (limb holding PRF may be dead) 6 5 PRF host-tree dead 59 6 PRF host-tree within 30 m of woodland edge 7 6 PRF host-tree over 30 m from the woodland edge 28 7 PRF host-tree less than 100 m away from river, canal or large pond or lake 8 7 PRF host-tree more than 100 m away from river, canal or large pond or lake 18 8 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 9 8 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 165 9 PRF on stem 10 9 PRF on branch 14 10 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H __________________________________________________________________________________________ B6 - 3

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 10 11

PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 11 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat Sm/T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 12 12 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Nathusius’ pipistrelle T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 12 PRF loose bark or ivy on stem 13 PRF loose bark Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Sm/T Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy Barbastelle T/H Daubenton’s bat T 14 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Daubenton’s bat Pm/T Noctule Pm/H/T (not below 4.6 m) Brown long-eared bat Pm/H/T 14 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 15 PRF a rot-hollow on branch Bechstein’s bat T Daubenton’s bat Sm/T Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 16 16 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Daubenton’s bat T Natterer’s bat T Nathusius’ pipistrelle T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 16 PRF loose-bark or ivy on branch 17 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T

__________________________________________________________________________________________ B6 - 4

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 18 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 19 18 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 193 19 PRF on stem 20 19 PRF on branch 24 20 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 20 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 21 21 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle T/H Soprano pipistrelle T Brown long-eared bat Pm/T/H 21 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 22 22 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Nathusius’ pipistrelle T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 22 PRF loose-bark or ivy on stem 23 23 PRF loose-bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Sm/T Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 23 PRF ivy on stem Barbastelle T/H Daubenton’s bat T 24 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Noctule Pm/H/T (not below 4.6 m) Brown long-eared bat Pm/H/T 24 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 25 25 PRF a rot-hollow on branch Bechstein’s bat T Daubenton’s bat T __________________________________________________________________________________________ 17

B6 - 5

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

29 29

Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle T/H Soprano pipistrelle T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 26 26 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Daubenton’s bat T Natterer’s bat T Nathusius’ pipistrelle T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 26 PRF loose-bark or ivy on branch 27 27 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 28 PRF host-tree over 30 m but within 100 m of woodland edge 29 28 PRF host-tree over 100 m from the woodland edge 50 PRF host-tree less than 100 m away from river, canal or large pond or lake 30 PRF host-tree more than 100 m away from river, canal or large pond or lake 40 30 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 31 30 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 202 PRF on stem 32 PRF on branch 36 32 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Daubenton’s bat Pm/T Brown long-eared bat Pm/T/H 32 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 33 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat Sm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 34 34 PRF a transverse crack, longitudinal split or loose bark on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 34 PRF loose-bark or ivy on stem 35 PRF loose-bark on stem Barbastelle Sm/T/H

__________________________________________________________________________________________ B6 - 6

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

41 41

Bechstein’s bat T Brandt’s bat Sm/T Daubenton’s bat T Brown long-eared bat T/H PRF ivy on stem Barbastelle T/H 36 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/H Daubenton’s bat Pm/T Brown long-eared bat Pm/H/T 36 PRF a knot-hole, rot-hole, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 37 PRF a rot-hollow on branch Bechstein’s bat T Daubenton’s bat Sm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 38 38 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 38 PRF loose-bark or ivy on branch 39 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Daubenton’s bat T Brown long-eared bat T/H PRF ivy on branch No data 40 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 41 40 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 211 PRF on stem 42 PRF on branch 46 42 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Daubenton’s bat T Brown long-eared bat Pm/T/H 42 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 43 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 44 44 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 44 PRF loose-bark or ivy on stem 45 45 PRF loose-bark on stem Barbastelle Sm/T/H

__________________________________________________________________________________________ B6 - 7

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

51 51

55 55

Bechstein’s bat T Brandt’s bat Pm/T Daubenton’s bat T Brown long-eared bat T/H PRF ivy on stem Barbastelle T/H 46 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Daubenton’s bat T Brown long-eared bat Pm/T/H 46 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 47 PRF a rot-hollow on branch Bechstein’s bat T Daubenton’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 48 48 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 48 PRF loose bark or ivy on branch 49 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Daubenton’s bat T Brown long-eared bat T/H PRF ivy on branch No data 50 PRF on stem 51 50 PRF on branch 55 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H PRF knot-hole, rot-hole, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 52 52 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 52 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 53 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 54 54 PRF loose bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Sm/T Brown long-eared bat Pm/T/H 54 PRF ivy on stem Barbastelle T/H PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 56 56 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 56 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 57 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 58

__________________________________________________________________________________________ B6 - 8

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 58

PRF loose-bark on branch

Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H 58 PRF ivy on branch No data 59 PRF host-tree within 30 m of woodland edge 60 59 PRF host-tree over 30 m from the woodland edge 70 60 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 61 60 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 81 61 PRF on stem 62 PRF on branch 66 62 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 62 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 63 63 PRF a knot-hole or rot-hollow on stem Barbastelle Pm/T ? Brandt’s bat Pm/T ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 63 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 64 64 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H ? Brandt’s bat Pm/T ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 64 PRF loose-bark or ivy on stem 65 65 PRF loose-bark on stem Barbastelle Sm/T/H ? Brandt’s bat Pm/T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 65 PRF ivy on stem Barbastelle T/H 66 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 66 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 67 67 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 67 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 68 68 PRF a transverse crack or longitudinal split on branch Barbastelle Pm/T/H ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 68 PRF loose-bark on branch 69 69 PRF loose-bark on branch Barbastelle Pm/T/H ? Common pipistrelle T __________________________________________________________________________________________ B6 - 9

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ ? Soprano pipistrelle T ? Brown long-eared bat T/H 69 PRF ivy on branch No data 70 PRF host-tree over 30 m but within 100 m of woodland edge (edge of woodland body, fire-break, ride etc.) 71 70 PRF host-tree over 100 m from the woodland edge 90 71 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 72 71 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 220 72 PRF on stem 73 72 PRF on branch 77 73 PRF a woodpecker-hollow on stem ? Brown long-eared bat Pm/T/H 73 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 74 74 PRF a rot-hollow on stem Barbastelle Pm/T ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 74 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 75 75 PRF a transverse crack or longitudinal split on stem Barbastelle Pm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 75 PRF loose-bark ivy on stem 76 76 PRF loose-bark on stem Barbastelle Sm/T/H ? Brandt’s bat Sm/T ? Brown long-eared bat T/H 76 PRF ivy on stem Barbastelle T/H 77 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 77 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 78 78 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H 78 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 79 79 PRF a transverse crack or longitudinal split on branch Barbastelle Pm/T/H ? Brown long-eared bat Pm/T/H 79 PRF loose-bark or ivy on branch 80 80 PRF loose-bark on branch Barbastelle Sm/T/H ? Brown long-eared bat T/H 80 PRF ivy on branch No data 81 PRF on stem 82 PRF on branch 86 82 PRF a woodpecker-hollow on stem ? Brown long-eared bat Pm/T/H 82 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 83 83 PRF a knot-hole or rot-hole on stem Barbastelle Pm/T ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 83 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 84 84 PRF a transverse crack, longitudinal split, crevice, loose bark on stem Barbastelle Pm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 84 PRF loose-bark or ivy on stem 85 85 PRF loose-bark on stem Barbastelle Sm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat T/H __________________________________________________________________________________________ B6 - 10

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 85

87 87

91 91

95 95

97 97

99 99

101 101

103

PRF ivy on stem Barbastelle T/H 86 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 86 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 87 PRF a knot-hole or rot-hollow on branch ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 88 88 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H ? Brown long-eared bat Pm/T/H 88 PRF loose-bark or ivy on branch 89 PRF loose-bark on branch Barbastelle Sm/T/H ? Brown long-eared bat T/H 89 PRF ivy on branch No data 90 PRF on stem 91 90 PRF on branch 95 PRF a woodpecker-hollow on stem ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 92 92 PRF a rot-hollow on stem Barbastelle Pm/T ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 92 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 93 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on stem 94 94 PRF loose-bark on stem Barbastelle Sm/T/H ? Brandt’s bat Sm/T ? Brown long-eared bat T/H 94 PRF ivy on stem Barbastelle T/H PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 96 96 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H 96 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 97 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 98 98 PRF loose-bark on branch Barbastelle Sm/T/H ? Brown long-eared bat T/H 98 PRF ivy on branch No data PRF host-tree within 30 m of woodland edge 100 PRF host-tree over 30 m from the woodland edge No data 100 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 101 100 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 102 PRF on branch 106 102 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T 102 PRF rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 103 PRF a rot-hollow on stem Brandt’s bat Pm/T Daubenton’s bat Sm/T Nathusius’ pipistrelle Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 104

__________________________________________________________________________________________ B6 - 11

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Brandt’s bat Pm/T/H Daubenton’s bat T Nathusius pipistrelle T 104 PRF loose-bark or ivy on stem 105 105 PRF loose-bark on stem Brandt’s bat Sm/T/H 105 PRF ivy on stem No data 106 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T 106 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 107 107 PRF a knot-hole or rot-hollow on branch Daubenton’s bat Pm/T Nathusius’ pipistrelle Pm/T/H 107 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 108 108 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat Pm/T Nathusius’ pipistrelle Pm/T/H 108 PRF loose-bark or ivy on branch No data 109 PRF host-tree alive (limb holding PRF may be dead) 110 109 PRF host-tree dead 132 110 PRF host-tree within 30 m of woodland edge 111 110 PRF host-tree over 30 m from the woodland edge 154 111 PRF host-tree less than 100 m away from river, canal or large pond or lake 112 111 PRF host-tree more than 100 m away from river, canal or large pond or lake 122 112 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 113 112 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 113 PRF on stem 114 113 PRF on branch 118 114 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 114 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 115 115 PRF a rot-hollow on stem Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Nathusius pipistrelle Pm/T/H Brown long-eared bat Pm/T/H 115 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 116 116 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Nathusius pipistrelle T Brown long-eared bat Pm/T/H 116 PRF loose-bark or ivy on stem 117 117 PRF loose-bark on stem Brown long-eared bat T/H 117 PRF ivy on stem No data 118 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 118 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 119 119 PRF a rot-hollow on branch Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Brown long-eared bat Pm/T/H 119 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 120 120 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Nathusius’ pipistrelle T Brown long-eared bat Pm/T/H __________________________________________________________________________________________ 104 PRF a transverse crack, longitudinal split or crevice on stem

B6 - 12

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 120 PRF loose-bark or ivy on branch 121 121 PRF loose-bark on branch Brown long-eared bat T/H 121 PRF ivy on branch No data 122 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 123 122 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 123 PRF on stem 124 123 PRF on branch 128 124 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 124 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 125 125 PRF a rot-hollow on stem Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Brown long-eared bat Pm/T/H 125 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 126 126 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Brown long-eared bat Pm/T/H 126 PRF loose-bark ivy on stem 127 127 PRF loose-bark on stem Brown long-eared bat T/H 127 PRF ivy on stem No data 128 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 128 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 129 129 PRF a rot-hollow on branch Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Brown long-eared bat Pm/T/H 129 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 130 130 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Brown long-eared bat Pm/T/H 130 PRF loose-bark or ivy on branch 131 131 PRF loose-bark on branch Brown long-eared bat T/H 131 PRF ivy on branch No data 132 PRF host-tree within 30 m of woodland edge 133 132 PRF host-tree over 30 m from the woodland edge 229 133 PRF host-tree less than 100 m away from river, canal or large pond or lake 134 133 PRF host-tree more than 100 m away from river, canal or large pond or lake 144 134 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 135 134 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data __________________________________________________________________________________________ B6 - 13

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 135 PRF on stem 135 PRF on branch 136 PRF a woodpecker-hollow on stem

137

139 139

141

143 143

145 145

147 147

149 149

151 151

153

136 140 ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 136 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 137 PRF a rot-hollow on stem ? Nathusius pipistrelle Pm/T/H ? Noctule Sm/T (not below 4.6 m) ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 138 138 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T ? Brown long-eared bat Pm/T/H 138 PRF loose-bark ivy on stem 139 PRF loose-bark on stem ? Brown long-eared bat T/H PRF ivy on stem No data 140 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 140 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 141 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 142 142 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T ? Brown long-eared bat Pm/T/H 142 PRF loose-bark or ivy on branch 143 PRF loose-bark on branch ? Brown long-eared bat T/H PRF ivy on branch No data 144 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 145 144 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 146 PRF on branch 150 146 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 146 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 147 PRF a knot-hole or rot-hole on stem ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 148 148 PRF a transverse crack, longitudinal split or crevice on stem ? Brown long-eared bat Pm/T/H 148 PRF loose-bark ivy on stem 149 PRF loose-bark on stem ? Brown long-eared bat T/H PRF ivy on stem No data 150 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 150 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 151 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 152 152 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat Pm/T/H 152 PRF loose-bark or ivy on branch 153 PRF loose-bark on branch ? Brown long-eared bat T/H

__________________________________________________________________________________________ B6 - 14

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 153 PRF ivy on branch No data 154 PRF host-tree less than 100 m away from river, canal or large pond or lake 155 154 PRF host-tree more than 100 m away from river, canal or large pond or lake 174 155 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 156 155 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 259 156 PRF on stem 157 156 PRF on branch 161 157 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H 157 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 158 158 PRF a rot-hollow on stem Natterer’s bat Pm/T Nathusius pipistrelle Pm/T/H Brown long-eared bat Pm/T/H 158 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 159 159 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Nathusius pipistrelle T Brown long-eared bat Pm/T/H 159 PRF loose-bark or ivy on stem 160 160 PRF loose-bark on stem Brown long-eared bat T/H 160 PRF ivy on stem No data 161 PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H 161 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 162 162 PRF a rot-hollow on branch Natterer’s bat Pm/T Nathusius’ pipistrelle Pm/T/H Brown long-eared bat Pm/T/H 162 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 163 163 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Nathusius’ pipistrelle T Brown long-eared bat Pm/T/H 163 PRF loose-bark or ivy on branch 164 164 PRF loose-bark on branch Brown long-eared bat T/H 164 PRF ivy on branch No data 165 PRF on stem 166 165 PRF on branch 170 166 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 166 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 167 167 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 167 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 168 168 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H 168 PRF loose-bark or ivy on stem 169 169 PRF loose-bark on stem Barbastelle Sm/T/H __________________________________________________________________________________________ B6 - 15

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

169

171

173

175 175

177 177

179 179

181 181

183 183

185 185

Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H PRF ivy on stem Barbastelle T/H 170 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 170 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 171 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 172 172 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 172 PRF loose-bark or ivy on branch 173 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H PRF ivy on branch No data 174 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 175 174 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 176 PRF on branch 180 176 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H 176 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 177 PRF a rot-hollow on stem Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 178 178 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Brown long-eared bat Pm/T/H 178 PRF loose-bark ivy on stem 179 PRF loose-bark on stem Brown long-eared bat T/H PRF ivy on stem No data 180 PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H 180 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 181 PRF a rot-hollow on branch Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 182 182 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Brown long-eared bat Pm/T/H 182 PRF loose-bark or ivy on branch 183 PRF loose-bark on branch Brown long-eared bat T/H PRF ivy on branch No data 184 Tree dead 185 184 Tree alive 186 PRF below 1 m on dead tree in broadleaved woodland Barbastelle T/H ? Brown long-eared bat T/H PRF below 1 m on dead tree in coniferous woodland ? Brown long-eared bat T

__________________________________________________________________________________________ B6 - 16

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

187 187

189 189

191 191

193 193

195

197

199

186 The broadleaved / coniferous woodland composed of trees of similar age (Little variation in structure) 187 186 The broadleaved / coniferous woodland composed of trees with a wide variety of ages (Well developed structure in shrub layer, understory and canopy) 190 Rot hollow on a live tree below 1 m ? Bechstein’s bat Sm/T/H ? Brown long-eared bat Pm/T/H Transverse crack, longitudinal split, loose-bark or ivy, on a live tree below 1 m 188 188 Transverse crack or longitudinal split ? Bechstein’s bat T ? Brown long-eared bat T/H 188 Loose-bark or ivy 189 Loose-bark ? Bechstein’s bat T ? Brown long-eared bat T/H Ivy No data 190 Rot hollow on a live tree below 1 m (including rot-hollow extending up into entirely hollow stem such as those for which entry is between buttress roots) Barbastelle T/H ? Bechstein’s bat T/H Brown long-eared bat Pm/T/H 190 Transverse crack, longitudinal split, loose-bark or ivy, on a live tree below 1 m 191 Transverse crack or longitudinal split Barbastelle T/H Brown long-eared bat Pm/T/H Loose-bark or ivy 192 192 Loose-bark Barbastelle T/H ? Bechstein’s bat T ? Brown long-eared bat T 192 Ivy No data PRF on stem 194 PRF on branch 198 194 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 194 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 195 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 196 196 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H 196 PRF loose-bark or ivy on stem 197 PRF loose-bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H PRF ivy on stem Barbastelle T/H 198 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/H Brown long-eared bat Pm/T/H 198 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 199 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 200 200 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 200 PRF loose-bark or ivy on branch 201

__________________________________________________________________________________________ B6 - 17

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 201 PRF loose-bark on branch

201

203 203

205

207 207

209

211 211

213

Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H PRF ivy on branch No data 202 PRF on stem 203 202 PRF on branch 207 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 204 204 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 204 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 205 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on stem 206 206 PRF loose-bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H 206 PRF ivy on stem Barbastelle T/H PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/H/T PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 208 208 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 208 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 209 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 210 210 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H 210 PRF ivy on branch No data PRF on stem 212 PRF on branch 216 212 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 212 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 213 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 214 214 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H 214 PRF loose-bark or ivy on stem 215

__________________________________________________________________________________________ B6 - 18

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 215 PRF loose-bark on stem

215

217

219

221 221

223

225 225

227 227

229 229

Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H PRF ivy on stem Barbastelle T/H 216 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 216 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 217 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 218 218 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 218 PRF loose-bark or ivy on branch 219 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H PRF ivy on branch No data 220 PRF on stem 221 220 PRF on branch 225 PRF a woodpecker-hollow on stem ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 222 222 PRF a knot-hole or rot-hole on stem Barbastelle Pm/T ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H 222 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 223 PRF a transverse crack, longitudinal split, crevice, loose bark on stem Barbastelle Pm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on stem 224 224 PRF loose-bark on stem Barbastelle Sm/T/H ? Brandt’s bat Pm/T ? Brown long-eared bat T/H 224 PRF ivy on stem Barbastelle T/H PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 226 226 PRF a knot-hole or rot-hollow on branch ? Brown long-eared bat Pm/T/H 226 PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 227 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 228 228 PRF loose-bark on branch Barbastelle Sm/T/H ? Brown long-eared bat T/H 228 PRF ivy on branch No data PRF host-tree less than 100 m away from river, canal or large pond or lake 230 PRF host-tree more than 100 m away from river, canal or large pond or lake 249 230 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 231 230 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or

__________________________________________________________________________________________ B6 - 19

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

231 231

233 233

235 235

237 237

239 239

241 241

243

245 245

247

 obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 240 PRF on stem 232 PRF on branch 236 232 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H 232 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 233 PRF a rot-hollow on stem Nathusius pipistrelle Pm/T/H Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 234 234 PRF a transverse crack, longitudinal split or crevice on stem Nathusius pipistrelle T Brown long-eared bat Pm/T/H 234 PRF loose-bark or ivy on stem 235 PRF loose-bark on stem Brown long-eared bat T/H PRF ivy on stem No data 236 PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H 236 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 237 PRF a rot-hollow on branch Nathusius’ pipistrelle Pm/T/H Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 238 238 PRF a transverse crack, longitudinal split or crevice on branch Nathusius’ pipistrelle T Brown long-eared bat Pm/T/H 238 PRF loose-bark or ivy on branch 239 PRF loose-bark on branch Brown long-eared bat T/H PRF ivy on branch No data 240 PRF on stem 241 240 PRF on branch 245 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/H/T PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 242 242 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat Pm/T/H 242 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 243 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on stem 244 244 PRF loose-bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H 244 PRF ivy on stem Barbastelle T/H PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 246 246 PRF a rot-hollow on branch Bechstein’s bat T Brown long-eared bat Pm/T/H 246 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 247 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle Pm/T/H Bechstein’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 248 248 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H 248 PRF ivy on branch No data

__________________________________________________________________________________________ B6 - 20

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 249 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 250 249 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 250 PRF on stem 251 250 PRF on branch 255 251 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H 251 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 252 252 PRF a rot-hollow on stem Brown long-eared bat Pm/T/H 252 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 253 253 PRF a transverse crack, longitudinal split or crevice on stem Brown long-eared bat Pm/T/H 253 PRF loose-bark ivy on stem 254 254 PRF loose-bark on stem Brown long-eared bat T/H 254 PRF ivy on stem No data 255 PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H 255 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 256 256 PRF a rot-hollow on branch Brown long-eared bat Pm/T/H 256 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 257 257 PRF a transverse crack, longitudinal split or crevice on branch Brown long-eared bat Pm/T/H 257 PRF loose-bark or ivy on branch 258 258 PRF loose-bark on branch Brown long-eared bat T/H 258 PRF ivy on branch No data 259 PRF on stem 260 259 PRF on branch 264 260 PRF a woodpecker-hollow on stem Bechstein’s bat Pm/T/H Brown long-eared bat Pm/T/H 260 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 261 261 PRF a rot-hollow on stem Barbastelle Pm/T Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 261 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 262 262 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle Pm/T/H Bechstein’s bat T Brandt’s bat Pm/T Natterer’s bat T Brown long-eared bat Pm/T/H 262 PRF loose-bark or ivy on stem 263 263 PRF loose-bark on stem Barbastelle Sm/T/H Bechstein’s bat T Brandt’s bat Pm/T Brown long-eared bat T/H 263 PRF ivy on stem Barbastelle T/H 264 PRF a woodpecker-hollow on branch Bechstein’s bat Pm/T/H Brown long-eared bat Pm/H/T 264 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 265 265 PRF a rot-hollow on branch Bechstein’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 265 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 266 __________________________________________________________________________________________ B6 - 21

BAT TREE HABITAT KEY

267

269 269

271 271

273 273

275 275

277

279

281

Barbastelle Pm/T/H Bechstein’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 266 PRF loose-bark or ivy on branch 267 PRF loose-bark on branch Barbastelle Sm/T/H Bechstein’s bat T Brown long-eared bat T/H 268 PRF above 1 m height 269 268 PRF below 1 m height 450 Broadleaved woodland 270 Coniferous / mixed woodland 375 270 Dry woodland – Oak, beech ash etc. 271 270 Wet woodland – Willow / alder carr 365 PRF host-tree alive (limb holding PRF may be dead) 272 PRF host-tree dead 325 272 PRF host-tree within 30 m of woodland edge 273 272 PRF host-tree over 30 m from the woodland edge 294 PRF host-tree less than 100 m away from river, canal or large pond or lake 274 PRF host-tree more than 100 m away from river, canal or large pond or lake 284 274 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 275 274 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 431 PRF on stem 276 PRF on branch 280 276 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) 276 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 277 PRF a rot-hollow on stem Barbastelle T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T ? Soprano pipistrelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 278 278 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T Leisler’s bat T/H (not below 9.5 m) ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 278 PRF loose bark or ivy on stem 279 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy Barbastelle T 280 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) 280 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 281 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T ? Soprano pipistrelle T PRF a transverse crack, longitudinal split, loose bark or ivy on branch 282

__________________________________________________________________________________________ B6 - 22

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 282 PRF a transverse crack, longitudinal split or crevice on branch

283

285 285

287

289

291

293

Barbastelle T ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 282 PRF loose-bark or ivy on branch 283 PRF loose-bark on branch Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy on branch No data 284 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 285 284 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 459 PRF on stem 286 PRF on branch 290 286 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) 286 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 287 PRF a rot-hollow on stem Barbastelle T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T ? Soprano pipistrelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 288 288 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T Leisler’s bat T/H (not below 9.5 m) ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 288 PRF loose-bark or ivy on stem 289 PRF loose-bark on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy on stem Barbastelle T 290 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) 290 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 291 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T ? Soprano pipistrelle T PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 292 292 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 292 PRF loose-bark or ivy on branch 293 PRF loose-bark on branch Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy on branch No data 294 PRF host-tree over 30 m but within 100 m of woodland edge 295 294 PRF host-tree over 100 m from the woodland edge 316

__________________________________________________________________________________________ B6 - 23

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 295 PRF host-tree less than 100 m away from river, canal or large pond or lake 296 295 PRF host-tree more than 100 m away from river, canal or large pond or lake 306 296 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 297 296 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 468 297 PRF on stem 298 297 PRF on branch 302 298 PRF a woodpecker-hollow on stem No data 298 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 299 299 PRF a rot-hollow on stem Barbastelle T 299 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 300 300 PRF a transverse crack, longitudinal split or loose bark on stem Barbastelle T 300 PRF loose-bark or ivy on stem 301 301 PRF loose-bark on stem Barbastelle T 301 PRF ivy on stem Barbastelle T 302 PRF a woodpecker-hollow on branch No data 302 PRF a knot-hole, rot-hole, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 303 303 PRF a rot-hollow on branch No data 303 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 304 304 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 304 PRF loose-bark or ivy on branch 305 305 PRF loose-bark on branch Barbastelle T 305 PRF ivy on branch No data 306 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 307 306 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 477 307 PRF on stem 308 307 PRF on branch 312 308 PRF a woodpecker-hollow on stem No data 308 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 309 309 PRF a rot-hollow on stem Barbastelle T 309 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 310 310 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 310 PRF loose-bark or ivy on stem 311 311 PRF loose-bark on stem Barbastelle T 311 PRF ivy on stem Barbastelle T 312 PRF a woodpecker-hollow on branch No data 312 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 313 313 PRF a rot-hollow on branch No data __________________________________________________________________________________________ B6 - 24

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 313 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 314 314 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 314 PRF loose bark or ivy on branch 315 315 PRF loose-bark on branch Barbastelle T 315 PRF ivy on branch No data 316 PRF on stem 317 316 PRF on branch 321 317 PRF a woodpecker-hollow on stem No data 317 PRF a knot-hole, rot-hole, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 318 318 PRF a rot-hollow on stem Barbastelle T 318 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 319 319 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 319 PRF loose bark or ivy on stem 320 320 PRF loose bark on stem Barbastelle T 320 PRF ivy on stem Barbastelle T 321 PRF a woodpecker-hollow on branch No data 321 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 322 322 PRF a rot-hollow on branch No data 322 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 323 323 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 323 PRF loose-bark or ivy on branch 324 324 PRF loose-bark on branch Barbastelle T 324 PRF ivy on branch No data 325 PRF host-tree within 30 m of woodland edge 326 325 PRF host-tree over 30 m from the woodland edge 336 326 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 327 326 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 347 327 PRF on stem 328 327 PRF on branch 332 328 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m) 328 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 329 329 PRF a knot-hole or rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T ? Soprano pipistrelle T 329 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 330 330 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 330 PRF loose-bark or ivy on stem 331 331 PRF loose-bark on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T 331 PRF ivy on stem Barbastelle T 332 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) 332 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 333 333 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T __________________________________________________________________________________________ B6 - 25

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ ? Soprano pipistrelle T 334 Barbastelle T ? Nathusius’ pipistrelle T ? Common pipistrelle T ? Soprano pipistrelle T 334 PRF loose-bark on branch 335 PRF loose-bark on branch Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy on branch No data 336 PRF host-tree over 30 m but within 100 m of woodland edge 337 336 PRF host-tree over 100 m from the woodland edge 356 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 338 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 486 338 PRF on stem 339 338 PRF on branch 343 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 340 340 PRF a rot-hollow on stem Barbastelle T 340 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 341 PRF a transverse crack or longitudinal split on stem Barbastelle T PRF loose-bark ivy on stem 342 342 PRF loose-bark on stem Barbastelle T 342 PRF ivy on stem Barbastelle T PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 344 344 PRF a rot-hollow on branch No data 344 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 345 PRF a transverse crack or longitudinal split on branch Barbastelle T PRF loose-bark or ivy on branch 346 346 PRF loose-bark on branch Barbastelle T 346 PRF ivy on branch No data PRF on stem 348 PRF on branch 352 348 PRF a woodpecker-hollow on stem No data 348 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 349 PRF a knot-hole or rot-hole on stem Barbastelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 350 350 PRF a transverse crack, longitudinal split, crevice, loose bark on stem Barbastelle T 350 PRF loose-bark or ivy on stem 351 PRF loose-bark on stem Barbastelle T PRF ivy on stem Barbastelle T/H 352 PRF a woodpecker-hollow on branch No data 352 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 353 PRF a knot-hole or rot-hollow on branch No data PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 354 354 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 354 PRF loose-bark or ivy on branch 355

333 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 334 PRF a transverse crack or longitudinal split on branch

335

337

339 339

341 341

343 343

345 345

347 347

349 349

351 351

353 353

__________________________________________________________________________________________ B6 - 26

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 355 PRF loose-bark on branch Barbastelle T 355 PRF ivy on branch No data 356 PRF on stem 357 356 PRF on branch 361 357 PRF a woodpecker-hollow on stem No data 357 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 358 358 PRF a rot-hollow on stem Barbastelle T 358 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 359 359 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 359 PRF loose-bark or ivy on stem 360 360 PRF loose-bark on stem Barbastelle T 360 PRF ivy on stem Barbastelle T 361 PRF a woodpecker-hollow on branch No data 361 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 362 362 PRF a rot-hollow on branch No data 362 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 363 363 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 363 PRF loose-bark or ivy on branch 364 364 PRF loose-bark on branch Barbastelle T 364 PRF ivy on branch No data 365 PRF host-tree within 30 m of woodland edge 366 365 PRF host-tree over 30 m from the woodland edge No data 366 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 367 366 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 367 PRF on stem 368 367 PRF on branch 372 368 PRF a woodpecker-hollow on stem No data 368 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 369 369 PRF a rot-hollow on stem ? Nathusius’ pipistrelle T 369 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 370 370 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T 370 PRF loose-bark or ivy on stem 371 371 PRF loose-bark on stem No data 371 PRF ivy on stem No data 372 PRF a woodpecker-hollow on branch No data 372 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 373 373 PRF a knot-hole or rot-hollow on branch ? Nathusius’ pipistrelle T 373 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 374 374 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T 374 PRF loose-bark or ivy on branch No data 375 PRF host-tree alive (limb holding PRF may be dead) 376 375 PRF host-tree dead 398 376 PRF host-tree within 30 m of woodland edge 377 376 PRF host-tree over 30 m from the woodland edge 420 377 PRF host-tree less than 100 m away from river, canal or large pond or lake 378 377 PRF host-tree more than 100 m away from river, canal or large pond or lake 388 378 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart); __________________________________________________________________________________________ B6 - 27

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

379 379

381 381

383 383

385 385

387 387

389 389

391 391

393 393

395 395

397

 no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 379 378 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 380 PRF on branch 384 380 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m) 380 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 381 PRF a rot-hollow on stem Noctule Sm/T (not below 4.6 m) ? Nathusius pipistrelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 382 382 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T 382 PRF loose-bark or ivy on stem 383 PRF loose-bark on stem No data PRF ivy on stem No data 384 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) 384 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 385 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 386 386 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T 386 PRF loose-bark or ivy on branch 387 PRF loose-bark on branch No data PRF ivy on branch No data 388 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 389 388 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 390 PRF on branch 394 390 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m) 390 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 391 PRF a rot-hollow on stem Noctule Sm/T (not below 4.6 m) PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 392 392 PRF a transverse crack, longitudinal split or crevice on stem No data 392 PRF loose-bark ivy on stem 393 PRF loose-bark on stem No data PRF ivy on stem No data 394 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) 394 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 395 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m) PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 396 396 PRF a transverse crack, longitudinal split or crevice on branch No data 396 PRF loose-bark or ivy on branch 397 PRF loose-bark on branch No data

__________________________________________________________________________________________ B6 - 28

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 397 PRF ivy on branch No data 398 PRF host-tree within 30 m of woodland edge 399 398 PRF host-tree over 30 m from the woodland edge 495 399 PRF host-tree less than 100 m away from river, canal or large pond or lake 400 399 PRF host-tree more than 100 m away from river, canal or large pond or lake 410 400 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 401 400 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 401 PRF on stem 402 401 PRF on branch 406 402 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m) 402 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 403 403 PRF a rot-hollow on stem ? Noctule Sm/T (not below 4.6 m) ? Nathusius pipistrelle T 403 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 404 404 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T 404 PRF loose-bark ivy on stem 405 405 PRF loose-bark on stem No data 405 PRF ivy on stem No data 406 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) 406 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 407 407 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle T 407 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 408 408 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T 408 PRF loose-bark or ivy on branch 409 409 PRF loose-bark on branch No data 409 PRF ivy on branch No data 410 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 411 410 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 411 PRF on stem 412 411 PRF on branch 416 412 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m) 412 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 413 413 PRF a knot-hole or rot-hole on stem ? Noctule Pm/T/H (not below 4.6 m) 413 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 414 414 PRF a transverse crack, longitudinal split or crevice on stem No data 414 PRF loose-bark ivy on stem 415 415 PRF loose-bark on stem No data __________________________________________________________________________________________ B6 - 29

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 415 PRF ivy on stem No data 416 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) 416 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 417 417 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) 417 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 418 418 PRF a transverse crack, longitudinal split or crevice on branch No data 418 PRF loose-bark or ivy on branch 419 419 PRF loose-bark on branch No data 419 PRF ivy on branch No data 420 PRF host-tree less than 100 m away from river, canal or large pond or lake 421 420 PRF host-tree more than 100 m away from river, canal or large pond or lake 440 421 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 422 421 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 525 422 PRF on stem 423 422 PRF on branch 427 423 PRF a woodpecker-hollow on stem No data 423 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 424 424 PRF a rot-hollow on stem ? Nathusius pipistrelle T 424 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 425 425 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T 425 PRF loose-bark or ivy on stem 426 426 PRF loose-bark on stem No data 426 PRF ivy on stem No data 427 PRF a woodpecker-hollow on branch No data 427 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 428 428 PRF a rot-hollow on branch ? Nathusius’ pipistrelle T 428 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 429 429 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T 429 PRF loose-bark or ivy on branch 430 430 PRF loose-bark on branch No data 430 PRF ivy on branch No data 431 PRF on stem 432 431 PRF on branch 436 432 PRF a woodpecker-hollow on stem No data 432 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 433 433 PRF a rot-hollow on stem Barbastelle T 433 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 434 434 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 434 PRF loose-bark or ivy on stem 435 435 PRF loose-bark on stem Barbastelle T 435 PRF ivy on stem Barbastelle T 436 PRF a woodpecker-hollow on branch No data 436 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 437 437 PRF a rot-hollow on branch No data 437 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 438 438 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 438 PRF loose-bark or ivy on branch 439 439 PRF loose-bark on branch Barbastelle T 439 PRF ivy on branch No data __________________________________________________________________________________________ B6 - 30

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

441 441

443 443

445 445

447 447

449 449

451 451

453 453

455 455

457 457

459 459

461 461

440 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 441 440 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data PRF on stem 442 PRF on branch 446 442 PRF a woodpecker-hollow on stem No data 442 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 443 PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 444 444 PRF a transverse crack, longitudinal split or crevice on stem No data 444 PRF loose-bark ivy on stem 445 PRF loose-bark on stem No data PRF ivy on stem No data 446 PRF a woodpecker-hollow on branch No data 446 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 447 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 448 448 PRF a transverse crack, longitudinal split or crevice on branch No data 448 PRF loose-bark or ivy on branch 449 PRF loose-bark on branch No data PRF ivy on branch No data 450 Tree dead 451 450 Tree alive 452 PRF below 1 m on dead tree in broadleaved woodland Barbastelle T PRF below 1 m on dead tree in coniferous woodland No data 452 The broadleaved / coniferous woodland composed of trees of similar age (Little variation in structure) 453 452 The broadleaved / coniferous woodland composed of trees with a wide variety of ages (Well developed structure in shrub layer, understory and canopy) 456 Rot hollow on a live tree below 1 m No data Transverse crack, longitudinal split, loose-bark or ivy, on a live tree below 1 m 454 454 Transverse crack or longitudinal split No data 454 Loose-bark or ivy 455 Loose-bark No data Ivy No data 456 Rot hollow on a live tree below 1 m (including rot-hollow extending up into entirely hollow stem such as those for which entry is between buttress roots) Barbastelle T 456 Transverse crack, longitudinal split, loose-bark or ivy, on a live tree below 1 m 457 Transverse crack or longitudinal split Barbastelle T Loose-bark or ivy 458 458 Loose-bark Barbastelle T 458 Ivy No data PRF on stem 460 PRF on branch 464 460 PRF a woodpecker-hollow on stem No data 460 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 461 PRF a rot-hollow on stem Barbastelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 462 462 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 462 PRF loose-bark or ivy on stem 463

__________________________________________________________________________________________ B6 - 31

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 â&#x20AC;&#x201C; Bat Tree Habitat Key __________________________________________________________________________________________ 463 PRF loose-bark on stem 463 PRF ivy on stem 464 PRF a woodpecker-hollow on branch 464 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 465 PRF a rot-hollow on branch 465 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 466 PRF a transverse crack, longitudinal split or crevice on branch 466 PRF loose-bark or ivy on branch 467 PRF loose-bark on branch 467 PRF ivy on branch 468 PRF on stem 468 PRF on branch 469 PRF a woodpecker-hollow on stem 469 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 470 PRF a rot-hollow on stem 470 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 471 PRF a transverse crack, longitudinal split or crevice on stem 471 PRF loose-bark or ivy on stem 472 PRF loose-bark on stem 472 PRF ivy on stem 473 PRF a woodpecker-hollow on branch 473 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 474 PRF a rot-hollow on branch 474 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 475 PRF a transverse crack, longitudinal split or crevice on branch 475 PRF loose-bark or ivy on branch 476 PRF loose-bark on branch 476 PRF ivy on branch 477 PRF on stem 477 PRF on branch 478 PRF a woodpecker-hollow on stem 478 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 479 PRF a rot-hollow on stem 479 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 480 PRF a transverse crack, longitudinal split or crevice on stem 480 PRF loose-bark or ivy on stem 481 PRF loose-bark on stem 481 PRF ivy on stem 482 PRF a woodpecker-hollow on branch 482 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 483 PRF a rot-hollow on branch 483 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 484 PRF a transverse crack, longitudinal split or crevice on branch 484 PRF loose-bark or ivy on branch 485 PRF loose-bark on branch 485 PRF ivy on branch 486 PRF on stem 486 PRF on branch 487 PRF a woodpecker-hollow on stem 487 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 488 PRF a knot-hole or rot-hole on stem 488 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 489 PRF a transverse crack, longitudinal split, crevice, loose bark on stem 489 PRF loose-bark or ivy on stem 490 PRF loose-bark on stem 490 PRF ivy on stem 491 PRF a woodpecker-hollow on branch 491 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 492 PRF a knot-hole or rot-hollow on branch

Barbastelle T Barbastelle T No data 465 No data 466 Barbastelle T 467 Barbastelle T No data 469 473 No data 470 Barbastelle T 471 Barbastelle T 472 Barbastelle T Barbastelle T No data 474 No data 475 Barbastelle T 476 Barbastelle T No data 478 482 No data 479 Barbastelle T 480 Barbastelle T 481 Barbastelle T Barbastelle T No data 483 No data 484 Barbastelle T 485 Barbastelle T No data 487 491 No data 488 Barbastelle T 489 Barbastelle T 490 Barbastelle T Barbastelle T No data 492 No data

__________________________________________________________________________________________ B6 - 32

ÂŠ Henry L. Andrews 2012

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 492 PRF a transverse crack, longitudinal split, crevice loose bark or ivy on branch 493 493 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 493 PRF loose-bark or ivy on branch 494 494 PRF loose-bark on branch Barbastelle T 494 PRF ivy on branch No data 495 PRF host-tree less than 100 m away from river, canal or large pond or lake 496 495 PRF host-tree more than 100 m away from river, canal or large pond or lake 515 496 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer;  no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 497 496 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m 506 497 PRF on stem 498 497 PRF on branch 502 498 PRF a woodpecker-hollow on stem No data 498 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 499 499 PRF a rot-hollow on stem ? Nathusius pipistrelle T 499 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 500 500 PRF a transverse crack, longitudinal split or crevice on stem ? Nathusius pipistrelle T 500 PRF loose-bark or ivy on stem 501 501 PRF loose-bark on stem No data 501 PRF ivy on stem No data 502 PRF a woodpecker-hollow on branch No data 502 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 503 503 PRF a rot-hollow on branch ? Nathusius’ pipistrelle T 503 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 504 504 PRF a transverse crack, longitudinal split or crevice on branch ? Nathusius’ pipistrelle T 504 PRF loose-bark or ivy on branch 505 505 PRF loose-bark on branch No data 505 PRF ivy on branch No data 506 PRF on stem 507 506 PRF on branch 511 507 PRF a woodpecker-hollow on stem No data 507 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 508 508 PRF a rot-hollow on stem Barbastelle T 508 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 509 509 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 509 PRF loose-bark or ivy on stem 510 510 PRF loose-bark on stem Barbastelle T 510 PRF ivy on stem Barbastelle T 511 PRF a woodpecker-hollow on branch No data 511 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 512 512 PRF a rot-hollow on branch No data 512 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 513 513 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 513 PRF loose-bark or ivy on branch 514 514 PRF loose-bark on branch Barbastelle T 514 PRF ivy on branch No data 515 Low-clutter environment: Typically but not exclusively woodland edge and / or trees within woodland margin (< 30 m from woodland edge) with:  widely spaced (stems more than 3 m apart);  no (or low density) shrub layer; __________________________________________________________________________________________ B6 - 33

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

515

517 517

519 519

521 521

523 523

525 525

527 527

529 529

531 531

533 533

 no obstructing/overhanging foliage;  distance between PRF and nearest obstacle beneath (branch, shrub layer etc.) > 1 m 516 High-clutter environment: Typically trees within woodland margin and wider woodland (> 30 m from woodland edge) with anyone of the following:  closely grouped stems less than 3m apart; and/or  dense shrub layer; and / or  obstructing/overhanging foliage; and/of  distance from the PFR to the nearest obstacle beneath < 1 m No data 516 PRF on stem 517 516 PRF on branch 521 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 518 518 PRF a rot-hollow on stem No data 518 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 519 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose-bark ivy on stem 520 520 PRF loose-bark on stem No data 520 PRF ivy on stem No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 522 522 PRF a rot-hollow on branch No data 522 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 523 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 524 524 PRF loose-bark on branch No data 524 PRF ivy on branch No data PRF on stem 526 PRF on branch 530 526 PRF a woodpecker-hollow on stem No data 526 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 527 PRF a rot-hollow on stem Barbastelle T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 528 528 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T 528 PRF loose-bark or ivy on stem 529 PRF loose-bark on stem Barbastelle T PRF ivy on stem Barbastelle T 530 PRF a woodpecker-hollow on branch No data 530 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 531 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on branch 532 532 PRF a transverse crack, longitudinal split or crevice on branch Barbastelle T 532 PRF loose-bark or ivy on branch 533 PRF loose-bark on branch Barbastelle T PRF ivy on branch Barbastelle T

KEY B Riparian: Broadleaved or coniferous tree within 100 m of a river, large pond (defined as any waterbody 5,000 m² (0.5 ha) to 20,000 m² (2 ha) in size) or lake (defined as any inland water-body greater than 20,000 m² in size). 1 Host tree within 100 m of slow or fast moving river 2 1 Host tree within 100 m of lake or large pond 16 2 Host tree within 100 m of slow-moving river (this includes ordinarily slow-moving rivers that are at highflow, the key distinction being that of a calm / smooth water surface) 3 2 Host tree within 100 m of fast moving / riffled river 30 3 PRF above 1 m height 4 PRF below 1 m height 43 4 PRF host-tree alive (limb holding PRF may be dead) 5 4 PRF host-tree dead 50 5 PRF host-tree within 60 m of woodland 6 PRF host-tree over 60 m from woodland 61 __________________________________________________________________________________________ B6 - 34

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 6 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 7 6 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 71 7 PRF on stem 8 7 PRF on branch 12 8 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H Brown long-eared bat Pm/T/H 8 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 9 9 PRF a rot-hollow on stem Daubenton’s bat Sm/T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 9 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 10 10 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 10 PRF loose bark or ivy on stem 11 11 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 11 PRF ivy Daubenton’s bat T 12 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 12 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 13 13 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 13 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 14 14 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 14 PRF loose-bark or ivy on branch 15 15 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 15 PRF ivy on branch Daubenton’s bat T 16 Host tree within 100 m of lake 17 16 Host tree within 100 m of large pond 80 17 PRF above 1 m height 18 17 PRF below 1 m height 93 __________________________________________________________________________________________ B6 - 35

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

19 19

21 21

18 PRF host-tree alive (limb holding PRF may be dead) 19 18 PRF host-tree dead 100 PRF host-tree within 60 m of woodland 20 PRF host-tree over 60 m from woodland 111 20 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1m 21 20 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 121 PRF on stem 22 PRF on branch 26 22 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 22 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 23 PRF a rot-hollow on stem Daubenton’s bat Sm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 24 24 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Nathusius’ pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 24 PRF loose bark or ivy on stem 25 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy Daubenton’s bat T 26 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 26 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 27 PRF a rot-hollow on branch Daubenton’s bat Sm/T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 28 28 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Nathusius’ pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 28 PRF loose-bark or ivy on branch 29 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T

__________________________________________________________________________________________ B6 - 36

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

31 31

39 39

43 43

Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 30 PRF above 1 m height 31 30 PRF below 1 m height 130 PRF host-tree alive (limb holding PRF may be dead) 32 PRF host-tree dead 137 32 PRF host-tree within 60 m of woodland 33 32 PRF host-tree over 60 m from woodland 148 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 34 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 158 34 PRF on stem 35 34 PRF on branch 39 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 36 36 PRF a rot-hollow on stem Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 36 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 37 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 38 38 PRF loose bark Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 38 PRF ivy No data PRF a woodpecker-hollow on branch

Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack or longitudinal split, crevice, loose bark or ivy on branch 40 40 PRF a rot-hollow on branch Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 40 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 41 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 42 42 PRF loose-bark on branch Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 42 PRF ivy on branch No data PRF host-tree alive (limb holding PRF may be dead) 44 PRF host-tree dead 167

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BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 44 PRF host-tree within 60 m of woodland 45 44 PRF host-tree over 60 m from woodland 173 45 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 46 45 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 46 PRF a woodpecker-hollow ? Brown long-eared bat Pm/T/H 46 PRF a rot-hollow, transverse or longitudinal split, crevice, loose bark or ivy 47 47 PRF a rot-hollow ? Brown long-eared bat Pm/T/H 47 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 48 48 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat Pm/T/H 48 PRF loose bark or ivy 49 49 PRF loose bark ? Brown long-eared bat T/H 49 PRF ivy No data 50 PRF host-tree within 60 m of woodland 51 50 PRF host-tree over 60 m from woodland 178 51 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 52 51 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 188 52 PRF on stem 53 52 PRF on branch 57 53 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 53 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 54 54 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 54 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 55 55 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 55 PRF loose bark or ivy on stem 56 56 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 56 PRF ivy Barbastelle T 57 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 57 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 58 58 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 58 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 59 59 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 59 PRF loose-bark or ivy on branch 60 __________________________________________________________________________________________ B6 - 38

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 60

PRF loose-bark on branch

? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H No data

60 PRF ivy on branch Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m

62 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 197 62 PRF on stem 63 62 PRF on branch 67 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 64 64 PRF a rot-hollow on stem Daubenton’s bat Sm/T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat T/H 64 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 65 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF loose bark or ivy on stem 66 66 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 66 PRF ivy Daubenton’s bat T PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 68 68 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat T Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat T/H 68 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 69 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF loose-bark or ivy on branch 70 70 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H

__________________________________________________________________________________________ B6 - 39

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

71 71

75 75

79 79

81 81

Daubenton’s bat T 72 76 Daubenton’s bat T Brown long-eared bat Pm/T/H 72 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 73 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 74 74 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 74 PRF loose bark or ivy on stem 75 PRF loose bark Daubenton’s bat T Brown long-eared bat T/H PRF ivy Daubenton’s bat T 76 PRF a woodpecker-hollow on branch Daubenton’s bat T Brown long-eared bat Pm/T/H 76 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 77 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 78 78 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 78 PRF loose-bark or ivy on branch 79 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 80 PRF above 1 m height 81 80 PRF below 1 m height 206 PRF host-tree alive (limb holding PRF may be dead) 82 PRF host-tree dead 213 82 PRF host-tree within 60 m of woodland 83 82 PRF host-tree over 60 m from woodland 224 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 84 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 234 84 PRF on stem 85 84 PRF on branch 89 PRF a woodpecker-hollow on stem Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 86 86 PRF a rot-hollow on stem Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T 70 PRF ivy on branch PRF on stem PRF on branch 72 PRF a woodpecker-hollow on stem

__________________________________________________________________________________________ B6 - 40

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Brown long-eared bat Pm/T/H 86 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 87 87 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 87 PRF loose bark or ivy on stem 88 88 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 88 PRF ivy Daubenton’s bat T 89 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 89 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 90 90 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 90 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 91 91 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Pm/T/H 91 PRF loose-bark or ivy on branch 92 92 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 92 PRF ivy on branch Daubenton’s bat T 93 PRF host-tree alive (limb holding PRF may be dead) 94 93 PRF host-tree dead 243 94 PRF host-tree within 60 m of woodland 95 94 PRF host-tree over 60 m from woodland 249 95 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 96 95 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 96 PRF a woodpecker-hollow ? Brown long-eared bat Pm/T/H 96 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 97 97 PRF a rot-hollow ? Brown long-eared bat Pm/T/H 97 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 98 98 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat Pm/T/H 98 PRF loose bark or ivy 99 99 PRF loose bark ? Brown long-eared bat T/H 99 PRF ivy No data 100 PRF host-tree within 60 m of woodland 101 100 PRF host-tree over 60 m from woodland 254 101 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and __________________________________________________________________________________________ B6 - 41

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 

a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 102 101 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 264 102 PRF on stem 103 102 PRF on branch 107 103 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 103 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 104 104 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 104 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 105 105 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Nathusius’ pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 105 PRF loose bark or ivy on stem 106 106 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 106 PRF ivy No data 107 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 107 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 108 108 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 108 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 109 109 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Nathusius’ pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 109 PRF loose-bark or ivy on branch 110 110 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 110 PRF ivy on branch No data 111 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 112 111 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 273 112 PRF on stem 113 112 PRF on branch 117 113 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) __________________________________________________________________________________________ B6 - 42

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

113

115

117

119

121 121

123

Noctule Pm/H/T (not below 4.6 m) Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 114 114 PRF a rot-hollow on stem Daubenton’s bat Sm/T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat T/H 114 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 115 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Nathusius’ pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF loose bark or ivy on stem 116 116 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 116 PRF ivy Daubenton’s bat T PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 118 118 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat T Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat T/H 118 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 119 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Nathusius’ pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF loose-bark or ivy on branch 120 120 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 120 PRF ivy on branch Daubenton’s bat T PRF on stem 122 PRF on branch 126 122 PRF a woodpecker-hollow on stem Daubenton’s bat T Brown long-eared bat Pm/T/H 122 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 123 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 124 124 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H

__________________________________________________________________________________________ B6 - 43

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 124 PRF loose bark or ivy on stem 125 PRF loose bark

125 Daubenton’s bat T Brown long-eared bat T/H 125 PRF ivy Daubenton’s bat T 126 PRF a woodpecker-hollow on branch Daubenton’s bat T Brown long-eared bat Pm/T/H 126 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 127 127 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 127 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 128 128 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H 128 PRF loose-bark or ivy on branch 129 129 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H 129 PRF ivy on branch Daubenton’s bat T 130 PRF host-tree alive (limb holding PRF may be dead) 131 130 PRF host-tree dead 282 131 PRF host-tree within 60 m of woodland 132 131 PRF host-tree over 60 m from woodland 288 132 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 133 132 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 133 PRF a woodpecker-hollow ? Brown long-eared bat T/H 133 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 134 134 PRF a rot-hollow on stem ? Brown long-eared bat T/H 134 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 135 135 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat T/H 135 PRF loose bark or ivy 136 136 PRF loose bark ? Brown long-eared bat T/H 136 PRF ivy No data 137 PRF host-tree within 60 m of woodland 138 137 PRF host-tree over 60 m from woodland 293 138 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 139 138 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 303 139 PRF on stem 140 139 PRF on branch 144 140 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 140 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 141 141 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 141 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 142 142 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T __________________________________________________________________________________________ B6 - 44

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

143

145

147

149 149

151

153

155

? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 142 PRF loose bark or ivy on stem 143 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H PRF ivy Barbastelle T 144 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 144 PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 145 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 146 146 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 146 PRF loose-bark or ivy on branch 147 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H PRF ivy on branch No data 148 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 149 148 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 312 PRF on stem 150 PRF on branch 154 150 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H 150 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 151 PRF a rot-hollow on stem Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 152 152 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 152 PRF loose bark or ivy on stem 153 PRF loose bark Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy No data 154 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 154 PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 155 PRF a rot-hollow on branch Natterer’s bat T

__________________________________________________________________________________________ B6 - 45

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

155

157

159 159

161

163 163

165 165

167 167

169 169

171 171

Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 156 156 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 156 PRF loose-bark or ivy on branch 157 PRF loose-bark on branch Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy on branch No data 158 PRF on stem 159 158 PRF on branch 163 PRF a woodpecker-hollow on stem Barbastelle T Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 160 160 PRF a rot-hollow on stem Barbastelle T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 160 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 161 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 162 162 PRF loose bark Barbastelle T Brown long-eared bat T/H 162 PRF ivy No data PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 164 164 PRF a rot-hollow on branch Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 164 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 165 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 166 166 PRF loose-bark on branch Brown long-eared bat T/H 166 PRF ivy on branch No data PRF host-tree within 60 m of woodland 168 PRF host-tree over 60 m from woodland 321 168 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 169 168 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse or longitudinal split, crevice, loose bark or ivy 170 170 PRF a rot-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 170 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 171 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat Pm/T/H PRF loose bark or ivy 172 172 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 172 PRF ivy No data

__________________________________________________________________________________________ B6 - 46

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 173 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 174 173 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 174 PRF a woodpecker-hollow ? Brown long-eared bat T/H 174 PRF a rot-hollow, transverse or longitudinal split, crevice, loose bark or ivy 175 175 PRF a rot-hollow ? Brown long-eared bat T/H 175 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 176 176 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat T/H 176 PRF loose bark or ivy 177 177 PRF loose bark ? Brown long-eared bat T/H 177 PRF ivy No data 178 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 179 178 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 326 179 PRF on stem 180 179 PRF on branch 184 180 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 180 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 181 181 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 181 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 182 182 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 182 PRF loose bark or ivy on stem 183 183 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 183 PRF ivy Barbastelle T 184 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 184 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 185 185 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 185 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 186 186 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 186 PRF loose-bark or ivy on branch 187 187 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 187 PRF ivy on branch No data __________________________________________________________________________________________ B6 - 47

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 188 PRF on stem 188 PRF on branch 189 PRF a woodpecker-hollow on stem 189

191 191

193 193

195 195

197 197

199

201 201

203

205 205

207 207

189 193 Barbastelle T ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 190 190 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H 190 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 191 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 192 192 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 192 PRF ivy Barbastelle T PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 194 194 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H 194 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 195 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 196 196 PRF loose-bark on branch ? Brown long-eared bat T/H 196 PRF ivy on branch No data PRF on stem 198 PRF on branch 202 198 PRF a woodpecker-hollow on stem Daubenton’s bat T Brown long-eared bat T/H 198 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 199 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 200 200 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 200 PRF loose bark or ivy on stem 201 PRF loose bark Daubenton’s bat T Brown long-eared bat T/H PRF ivy Daubenton’s bat T 202 PRF a woodpecker-hollow on branch Daubenton’s bat T Brown long-eared bat T/H 202 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 203 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 204 204 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 204 PRF loose-bark or ivy on branch 205 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 206 PRF host-tree alive (limb holding PRF may be dead) 207 206 PRF host-tree dead 335 PRF host-tree within 60 m of woodland 208 PRF host-tree over 60 m from woodland 341 208 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 209

__________________________________________________________________________________________ B6 - 48

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

209 209

211 211

213 213

215 215

217

219

221

223

208 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 210 210 PRF a rot-hollow Brown long-eared bat Pm/T/H 210 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 211 PRF a transverse crack, longitudinal split or crevice Brown long-eared bat Pm/T/H PRF loose bark or ivy 212 212 PRF loose bark Brown long-eared bat T/H 212 PRF ivy No data PRF host-tree within 60 m of woodland 214 PRF host-tree over 60 m from woodland 346 214 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 215 214High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 356 PRF on stem 216 PRF on branch 220 216 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/H/T (not below 4.6 m) ? Brown long-eared bat Pm/T/H 216 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 217 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 218 218 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 218 PRF loose bark or ivy on stem 219 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H PRF ivy No data 220 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 220 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 221 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 222 222 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Pm/T/H 222 PRF loose-bark or ivy on branch 223 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H PRF ivy on branch No data

__________________________________________________________________________________________ B6 - 49

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

225 225

227

229

231

233

224 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 225 224 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 365 PRF on stem 226 PRF on branch 230 226 PRF a woodpecker-hollow on stem Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H 226 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 227 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 228 228 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 228 PRF loose bark or ivy on stem 229 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy Daubenton’s bat T 230 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat T/H 230 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 231 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m) Soprano pipistrelle Pm/T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 232 232 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 232 PRF loose-bark or ivy on branch 233 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 234 PRF on stem 235 234 PRF on branch 239

__________________________________________________________________________________________ B6 - 50

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Daubenton’s bat T Brown long-eared bat Pm/H/T PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 236 236 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 236 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 237 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 238 238 PRF loose bark Daubenton’s bat T Brown long-eared bat T/H 238 PRF ivy Daubenton’s bat T PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 240 240 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 240 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 241 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 242 242 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H 242 PRF ivy on branch Daubenton’s bat T PRF host-tree within 60 m of woodland 244 PRF host-tree over 60 m from woodland 374 244 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 245 244 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 246 246 PRF a rot-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 246 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 247 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat Pm/T/H PRF loose bark or ivy 248 248 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 248 PRF ivy No data Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 250 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 250 PRF a woodpecker-hollow ? Brown long-eared bat Pm/T/H 250 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 251 PRF a rot-hollow ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 252 252 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat Pm/T/H

235 PRF a woodpecker-hollow on stem 235

237

239 239

241

243 243

245 245

247 247

249

251 251

__________________________________________________________________________________________ B6 - 51

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 252 PRF loose bark or ivy 253 253 PRF loose bark ? Brown long-eared bat T/H 253 PRF ivy No data 254 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 255 254 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 379 255 PRF on stem 256 255 PRF on branch 260 256 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 256 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 257 257 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 257 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 258 258 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Nathusius’ pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 258 PRF loose bark or ivy on stem 259 259 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 259 PRF ivy No data 260 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat Pm/T/H 260 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 261 261 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 261 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 262 262 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Nathusius’ pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 262 PRF loose-bark or ivy on branch 263 263 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 263 PRF ivy on branch No data 264 PRF on stem 265 264 PRF on branch 269 265 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H 265 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 266 266 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H __________________________________________________________________________________________ B6 - 52

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 266 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 267 267 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat Pm/T/H 267 PRF loose bark or ivy on stem 268 268 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 268 PRF ivy No data 269 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 269 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 270 270 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H 270 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 271 271 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat Pm/T/H 271 PRF loose-bark or ivy on branch 272 272 PRF loose-bark on branch ? Brown long-eared bat T/H 272 PRF ivy on branch No data 273 PRF on stem 274 273 PRF on branch 278 274 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Brown long-eared bat T/H 274 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 275 275 PRF a rot-hollow on stem Daubenton’s bat Sm/T Natterer’s bat T Brown long-eared bat T/H 275 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 276 276 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 276 PRF loose bark or ivy on stem 277 277 PRF loose bark Daubenton’s bat T Brown long-eared bat T/H 277 PRF ivy Daubenton’s bat T 278 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Brown long-eared bat T/H 278 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 279 279 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat T Brown long-eared bat T/H 279 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 280 280 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 280 PRF loose-bark or ivy on branch 281 281 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H 281 PRF ivy on branch Daubenton’s bat T 282 PRF host-tree within 60 m of woodland 283 282 PRF host-tree over 60 m from woodland 388 283 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 284 283 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 284 PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 284 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 285 285 PRF a rot-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 285 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 286 __________________________________________________________________________________________ B6 - 53

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 286 PRF a transverse crack, longitudinal split or crevice 286 PRF loose bark or ivy 287 PRF loose bark

Barbastelle T ? Brown long-eared bat Pm/T/H 287 Barbastelle T ? Brown long-eared bat T/H No data

287 PRF ivy 288 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 289 288 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 289 PRF a woodpecker-hollow ? Brown long-eared bat T/H 289 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 290 290 PRF a rot-hollow on stem ? Brown long-eared bat T/H 290 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 291 291 PRF a transverse crack, longitudinal split or crevice ? Brown long-eared bat T/H 291 PRF loose bark or ivy 292 292 PRF loose bark ? Brown long-eared bat T/H 292 PRF ivy No data 293 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 294 293 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 393 294 PRF on stem 295 294 PRF on branch 299 295 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 295 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 296 296 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 296 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 297 297 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 297 PRF loose bark or ivy on stem 298 298 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 298 PRF ivy Barbastelle T 299 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 299 PRF a rot-hollow, transverse crack or longitudinal split, crevice, loose bark or ivy on branch 300 300 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 300 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 301 301 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T __________________________________________________________________________________________ B6 - 54

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ ? Brown long-eared bat T/H 302 ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 302 PRF ivy on branch No data PRF on stem 304 PRF on branch 308 304 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H 304 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 305 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 306 306 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat Pm/T/H 306 PRF loose bark or ivy on stem 307 PRF loose bark Barbastelle T ? Brown long-eared bat T/H PRF ivy Barbastelle T 308 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 308 PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 309 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 310 310 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat Pm/T/H 310 PRF loose-bark or ivy on branch 311 PRF loose-bark on branch ? Brown long-eared bat T/H PRF ivy on branch No data 312 PRF on stem 313 312 PRF on branch 317 PRF a woodpecker-hollow on stem Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 314 314 PRF a rot-hollow on stem Natterer’s bat T Brown long-eared bat T/H 314 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 315 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Brown long-eared bat T/H PRF loose bark or ivy on stem 316 316 PRF loose bark Brown long-eared bat T/H 316 PRF ivy No data PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 318 318 PRF a rot-hollow on branch Natterer’s bat T Brown long-eared bat T/H 318 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 319 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Brown long-eared bat T/H PRF loose-bark or ivy on branch 320 320 PRF loose-bark on branch Brown long-eared bat T/H 320 PRF ivy on branch No data Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 322 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 322 PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat T/H

301 PRF loose-bark or ivy on branch 302 PRF loose-bark on branch

303 303

305 305

307 307

309 309

311 311

313 313

315 315

317 317

319 319

321

__________________________________________________________________________________________ B6 - 55

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 322 PRF a rot-hollow, transverse or longitudinal split, crevice, loose bark or ivy 323 323 PRF a rot-hollow Barbastelle T ? Brown long-eared bat T/H 323 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 324 324 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat T/H 324 PRF loose bark or ivy 325 325 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 325 PRF ivy No data 326 PRF on stem 327 326 PRF on branch 331 327 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat T/H 327 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 328 328 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H 328 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 329 329 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat T/H 329 PRF loose bark or ivy on stem 330 330 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 330 PRF ivy Barbastelle T 331 PRF a woodpecker-hollow on branch ? Brown long-eared bat T/H 331 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 332 332 PRF a rot-hollow on branch ? Brown long-eared bat T/H 332 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 333 333 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat T/H 333 PRF loose-bark or ivy on branch 334 334 PRF loose-bark on branch ? Brown long-eared bat T/H 334 PRF ivy on branch No data 335 PRF host-tree within 60 m of woodland 336 335 PRF host-tree over 60 m from woodland edge 402 336 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 337 336 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 337 PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 337 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 338 338 PRF a rot-hollow Barbastelle T ? Brown long-eared bat Pm/T/H 338 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 339 339 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat Pm/T/H 339 PRF loose bark or ivy 340 340 PRF loose bark Barbastelle T ? Brown long-eared bat Pm/T/H 340 PRF ivy No data 341 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 342 341 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 342 PRF a woodpecker-hollow on stem Brown long-eared bat T/H __________________________________________________________________________________________ B6 - 56

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 342 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 343 343 PRF a rot-hollow on stem Brown long-eared bat T/H 343 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 344 344 PRF a transverse crack, longitudinal split or crevice Brown long-eared bat T/H 344 PRF loose bark or ivy 345 345 PRF loose bark Brown long-eared bat T/H 345 PRF ivy No data 346 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 347 346 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 407 347 PRF on stem 348 347 PRF on branch 352 348 PRF a woodpecker-hollow on stem Barbastelle T ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 348 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 349 349 PRF a rot-hollow on stem Barbastelle T ? Noctule Sm/T (not below 4.6 m) ? Nathusius’ pipistrelle Pm/T/H ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 349 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 350 350 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 350 PRF loose bark or ivy on stem 351 351 PRF loose bark Barbastelle T ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 351 PRF ivy No data 352 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m) ? Brown long-eared bat T/H 352 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 353 353 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m) ? Soprano pipistrelle Pm/T ? Brown long-eared bat T/H 353 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 354 354 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 354 PRF loose-bark or ivy on branch 355 355 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H 355 PRF ivy on branch No data 356 PRF on stem 357 356 PRF on branch 361 357 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat Pm/T/H 357 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 358 358 PRF a rot-hollow on stem Barbastelle T __________________________________________________________________________________________ B6 - 57

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

359 359

361 361

363 363

365 365

367

369 369

371

373 373

375 375

377

? Brown long-eared bat Pm/T/H 358 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 359 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat Pm/T/H PRF loose bark or ivy on stem 360 360 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 360 PRF ivy No data PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 362 362 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H 362 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 363 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat Pm/T/H PRF loose-bark or ivy on branch 364 364 PRF loose-bark on branch ? Brown long-eared bat T/H 364 PRF ivy on branch No data PRF on stem 366 PRF on branch 370 366 PRF a woodpecker-hollow on stem Daubenton’s bat T Brown long-eared bat T/H 366 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 367 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 368 368 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 368 PRF loose bark or ivy on stem 369 PRF loose bark Daubenton’s bat T Brown long-eared bat T/H PRF ivy Daubenton’s bat T 370 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Brown long-eared bat T/H 370 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 371 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 372 372 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Brown long-eared bat T/H 372 PRF loose-bark or ivy on branch 373 PRF loose-bark on branch Daubenton’s bat T Brown long-eared bat T/H PRF ivy on branch Daubenton’s bat T 374 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 375 374 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 376 376 PRF a rot-hollow Barbastelle T ? Brown long-eared bat T/H 376 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 377 PRF a transverse crack, longitudinal split or crevice Barbastelle T

__________________________________________________________________________________________ B6 - 58

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ ? Brown long-eared bat T/H 378 Barbastelle T ? Brown long-eared bat T/H 378 PRF ivy No data PRF on stem 380 PRF on branch 384 380 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat T/H 380 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 381 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 382 382 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat T/H 382 PRF loose bark or ivy on stem 383 PRF loose bark Barbastelle T ? Brown long-eared bat T/H PRF ivy No data 384 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 384 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 385 PRF a rot-hollow on branch ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 386 386 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat T/H 386 PRF loose-bark or ivy on branch 387 PRF loose-bark on branch ? Brown long-eared bat T/H PRF ivy on branch No data 388 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 389 388 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow Barbastelle T ? Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 390 390 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H 390 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 391 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat T/H PRF loose bark or ivy 392 392 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 392 PRF ivy No data PRF on stem 394 PRF on branch 398 394 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat T/H 394 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 395 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 396 396 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat T/H 396 PRF loose bark or ivy on stem 397 PRF loose bark Barbastelle T ? Brown long-eared bat T/H PRF ivy Barbastelle T

377 PRF loose bark or ivy 378 PRF loose bark

379 379

381 381

383 383

385 385

387 387

389 389

391 391

393 393

395 395

397 397

__________________________________________________________________________________________ B6 - 59

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

399 399

401 401

403 403

405 405

407 407

409 409

411 411

413 413

415 415

398 PRF a woodpecker-hollow on branch ? Brown long-eared bat T/H 398 PRF rot-hollow, transverse crack or longitudinal split, crevice, bark or ivy on branch 399 PRF a rot-hollow on branch ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 400 400 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat T/H 400 PRF loose-bark or ivy on branch 401 PRF loose-bark on branch ? Brown long-eared bat T/H PRF ivy on branch No data 402 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 403 402 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy 404 404 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H 404 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy 405 PRF a transverse crack, longitudinal split or crevice Barbastelle T ? Brown long-eared bat T/H PRF loose bark or ivy 406 406 PRF loose bark Barbastelle T ? Brown long-eared bat T/H 406 PRF ivy No data PRF on stem 408 PRF on branch 412 408 PRF a woodpecker-hollow on stem Barbastelle T ? Brown long-eared bat T/H 408 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 409 PRF a rot-hollow on stem Barbastelle T ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 410 410 PRF a transverse crack, longitudinal split or crevice on stem Barbastelle T ? Brown long-eared bat T/H 410 PRF loose bark or ivy on stem 411 PRF loose bark Barbastelle T ? Brown long-eared bat T/H PRF ivy No data 412 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H ? Brown long-eared bat T/H 412 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 413 PRF a rot-hollow on branch ? Brown long-eared bat T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 414 414 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat T/H 414 PRF loose-bark or ivy on branch 415 PRF loose-bark on branch ? Brown long-eared bat T/H PRF ivy on branch No data

KEY C Hedgerow: Broadleaved or coniferous tree on hedgerow, tree-line or shelterbelt. 1 Continuous hedgerow > 1 m tall having connectivity (on one or both sides - no single gap greater than 20 m) with a network of linear features (i.e. other well-structured hedgerows, boundary banks, river, woodland edge etc.) 2 1 Discontinuous hedgerow with gaps > 20 m tall and/or having no or only loose connectivity with other hedges or linear features. Key D – Isolated trees 2 PRF above 1 m height 3 2 PRF below 1 m height 162 __________________________________________________________________________________________ B6 - 60

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 3 Hedge having connectivity (in itself or via a network of linear features) with woodland within 500 m of PRF host-tree. 4 3 Hedge having no connectivity (or connectivity but with gaps greater than 20 m) with woodland, or no woodland within 500 m of PRF host-tree 83 4 PRF host-tree less than 100 m away from river, canal or large pond or lake 5 4 PRF host-tree more than 100 m away from river, canal or large pond or lake 44 5 PRF host-tree alive (limb holding PRF may be dead) 6 5 PRF host-tree dead 25 6 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 7 6 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 16 7 PRF on stem 8 7 PRF on branch 12 8 PRF a woodpecker-hollow on stem Daubenton’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m) Brown long-eared bat Pm/T/H 8 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 9 9 PRF a rot-hollow on stem Daubenton’s bat Sm/T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 9 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 10 10 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H 10 PRF loose bark or ivy on stem 11 11 PRF loose bark Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Sm/T/H 11 PRF ivy Daubenton’s bat T 12 PRF a woodpecker-hollow on branch Daubenton’s bat Pm/T Noctule Pm/T/H (not below 4.6 m height) Brown long-eared bat Pm/T/H 12 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 13 13 PRF a rot-hollow on branch Daubenton’s bat Sm/T Natterer’s bat Pm/T Noctule Sm/T (not below 4.6 m height) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T Brown long-eared bat Pm/T/H 13 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 14 14 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Nathusius pipistrelle T Common pipistrelle T __________________________________________________________________________________________ B6 - 61

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

19 19

21 21

23 23

27 27

31 31

Soprano pipistrelle T Brown long-eared bat T/H 14 PRF loose-bark or ivy on branch 15 PRF loose-bark on branch Daubenton’s bat T Common pipistrelle T Soprano pipistrelle T Brown long-eared bat Sm/T/H PRF ivy on branch Daubenton’s bat T 16 PRF on stem 17 16 PRF on branch 21 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 18 18 PRF a rot-hollow on stem Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 18 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 19 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat T Brown long-eared bat T/H PRF loose bark or ivy on stem 20 20 PRF loose bark Brown long-eared bat Sm/T/H 20 PRF ivy No data PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 22 22 PRF a rot-hollow on branch Natterer’s bat Pm/T Brown long-eared bat Pm/T/H 22 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 23 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat T Brown long-eared bat T/H PRF loose-bark or ivy on branch 24 24 PRF loose-bark on branch Brown long-eared bat Sm/T/H 24 PRF ivy on branch No data Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 26 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 35 26 PRF on stem 27 26 PRF on branch 31 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m height) ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 28 28 PRF a rot-hollow on stem ? Noctule Sm/T (not below 4.6 m height) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 28 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 29 PRF a transverse crack, longitudinal split or crevice on stem ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat/T/H PRF loose bark or ivy on stem 30 30 PRF loose bark ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Sm/T/H 30 PRF ivy No data PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m height) ? Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 32

__________________________________________________________________________________________ B6 - 62

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 32 PRF a rot-hollow on branch

35 35

37 37

39 39

41 41

43 43

? Noctule Sm/T (not below 4.6 m height) ? Soprano pipistrelle Pm/T ? Brown long-eared bat Pm/T/H 32 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 33 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat T/H PRF loose-bark or ivy on branch 34 34 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T ? Brown long-eared bat Sm/T/H 34 PRF ivy on branch No data PRF on stem 36 PRF on branch 40 36 PRF a woodpecker-hollow on stem ? Brown long-eared bat Pm/T/H 36 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 37 PRF a rot-hollow on stem ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 38 38 PRF a transverse crack, longitudinal split or crevice on stem ? Brown long-eared bat T/H 38 PRF loose bark or ivy on stem 39 PRF loose bark ? Brown long-eared bat Sm/T/H PRF ivy No data 40 PRF a woodpecker-hollow on branch ? Brown long-eared bat Pm/T/H 40 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 41 PRF a rot-hollow on branch ? Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 42 42 PRF a transverse crack, longitudinal split or crevice on branch ? Brown long-eared bat T/H 42 PRF loose-bark or ivy on branch 43 PRF loose-bark on branch ? Brown long-eared bat Sm/T/H PRF ivy on branch No data 44 PRF host-tree alive (limb holding PRF may be dead) 45 44 PRF host-tree dead 64 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 46 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 55 46 PRF on stem 47 46 PRF on branch 51 PRF a woodpecker-hollow on stem Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m height) Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 48 48 PRF a rot-hollow on stem Daubenton’s bat T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m height) Brown long-eared bat Pm/T/H 48 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 49 PRF a transverse crack, longitudinal split or crevice on stem Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T

__________________________________________________________________________________________ B6 - 63

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

55 55

57 57

59 59

61 61

63 63

Brown long-eared bat T/H 50 Daubenton’s bat T Soprano pipistrelle T Brown long-eared bat Sm/T/H 50 PRF ivy Daubenton’s bat T PRF a woodpecker-hollow on branch Daubenton’s bat T Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m height) Brown long-eared bat Pm/T/H PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 52 52 PRF a rot-hollow on branch Daubenton’s bat T Natterer’s bat Pm/T Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m height) Brown long-eared bat Pm/T/H 52 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 53 PRF a transverse crack, longitudinal split or crevice on branch Daubenton’s bat T Natterer’s bat T Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T Brown long-eared bat T/H PRF loose-bark or ivy on branch 54 54 PRF loose-bark on branch Daubenton’s bat T Soprano pipistrelle T Brown long-eared bat Sm/T/H 54 PRF ivy on branch Daubenton’s bat T PRF on stem 56 PRF on branch 60 56 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H 56 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 57 PRF a rot-hollow on stem Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 58 58 PRF a transverse crack, longitudinal split or crevice on stem Natterer’s bat Pm/T Brown long-eared bat T/H 58 PRF loose bark or ivy on stem 59 PRF loose bark Brown long-eared bat Sm/T/H PRF ivy No data 60 PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H 60 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 61 PRF a rot-hollow on branch Natterer’s bat Pm/T Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 62 62 PRF a transverse crack, longitudinal split or crevice on branch Natterer’s bat Pm/T Brown long-eared bat T/H 62 PRF loose-bark or ivy on branch 63 PRF loose-bark on branch Brown long-eared bat Sm/T/H PRF ivy on branch No data 64 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 65 64 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 74 PRF loose bark or ivy on stem 50 PRF loose bark

__________________________________________________________________________________________ B6 - 64

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 65 65

67 67

69 69

71 71

73 73

75 75

77 77

79 79

81 81

83 83

PRF on stem PRF on branch 66 PRF a woodpecker-hollow on stem

66 70 Noctule Pm/T/H (not below 4.6 m height) Brown long-eared bat Pm/T/H 66 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 67 PRF a rot-hollow on stem Noctule Sm/T (not below 4.6 m height) Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 68 68 PRF a transverse crack, longitudinal split or crevice on stem Soprano pipistrelle T Brown long eared bat T/H 68 PRF loose bark or ivy on stem 69 PRF loose bark Soprano pipistrelle T Brown long eared bat Sm/T/H PRF ivy No data 70 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) Brown long-eared bat Pm/T/H 70 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 71 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m height) Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, loose bark or ivy on branch 72 72 PRF a transverse crack, longitudinal split or crevice on branch Soprano pipistrelle T Brown long eared bat T/H 72 PRF loose-bark or ivy on branch 73 PRF loose-bark on branch Soprano pipistrelle T Brown long eared bat Sm/T/H PRF ivy on branch No data 74 PRF on stem 75 74 PRF on branch 79 PRF a woodpecker-hollow on stem Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 76 76 PRF a rot-hollow on stem Brown long-eared bat Pm/T/H 76 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 77 PRF a transverse crack, longitudinal split or crevice on stem Brown long-eared bat T/H PRF loose bark or ivy on stem 78 78 PRF loose bark Brown long-eared bat Sm/T/H 78 PRF ivy No data PRF a woodpecker-hollow on branch Brown long-eared bat Pm/T/H PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 80 80 PRF a rot-hollow on branch Brown long-eared bat Pm/T/H 80 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 81 PRF a transverse crack, longitudinal split or crevice on branch Brown long-eared bat T/H PRF loose-bark or ivy on branch 82 82 PRF loose-bark on branch Brown long-eared bat Sm/T/H 82 PRF ivy on branch No data PRF host-tree less than 100 m away from river, canal or large pond or lake 84 PRF host-tree more than 100 m away from river, canal or large pond or lake 123 84 PRF host-tree alive (limb holding PRF may be dead) 85 84 PRF host-tree dead 104 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 86 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 95 86 PRF on stem 87 86 PRF on branch 91

__________________________________________________________________________________________ B6 - 65

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 87 87

91 92

95 95

97 97

99 99

101 101

103 103

105 105

Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4 .6 m) PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 88 88 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T 88 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 89 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T PRF loose bark or ivy on stem 90 90 PRF loose bark Common pipistrelle T Soprano pipistrelle T 90 PRF ivy No data PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 92 92 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m height) Nathusius’ pipistrelle Pm/T/H Soprano pipistrelle Pm/T 92 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 93 PRF a transverse crack, longitudinal split or crevice on branch Nathusius pipistrelle T Common pipistrelle T Soprano pipistrelle T PRF loose-bark or ivy on branch 94 94 PRF loose-bark on branch Common pipistrelle T Soprano pipistrelle T 94 PRF ivy on branch No data PRF on stem 96 PRF on branch 100 96 PRF a woodpecker-hollow on stem No data 96 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 97 PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 98 98 PRF a transverse crack, longitudinal split or crevice on stem No data 98 PRF loose bark or ivy on stem 99 PRF loose bark No data PRF ivy No data 100 PRF a woodpecker-hollow on branch No data 100 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 101 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, loose bark or ivy on branch 102 102 PRF a transverse crack, longitudinal split or crevice on branch No data 102 PRF loose-bark or ivy on branch 103 PRF loose-bark on branch No data PRF ivy on branch No data 104 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 105 104 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 114 PRF on stem 106 PRF on branch 110 106 PRF a woodpecker-hollow on stem ? Noctule Pm/T/H (not below 4.6 m height) 106 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 107 PRF a woodpecker-hollow on stem

__________________________________________________________________________________________ B6 - 66

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 107 PRF a rot-hollow on stem 107

109 109

111 111

113 113

115 115

117 117

119 119

121 121

123 123

125 125

127 127

? Noctule Sm/T (not below 4.6 m height) ? Soprano pipistrelle Pm/T PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 108 108 PRF a transverse crack, longitudinal split or crevice on stem ? Common pipistrelle T ? Soprano pipistrelle T 108 PRF loose bark or ivy on stem 109 PRF loose bark ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy No data 110 PRF a woodpecker-hollow on branch ? Noctule Pm/T/H (not below 4.6 m height) 110 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 111 PRF a rot-hollow on branch ? Noctule Sm/T (not below 4.6 m height) ? Soprano pipistrelle Pm/T PRF a transverse crack, longitudinal split, loose bark or ivy on branch 112 112 PRF a transverse crack, longitudinal split or crevice on branch ? Common pipistrelle T ? Soprano pipistrelle T 112 PRF loose-bark or ivy on branch 113 PRF loose-bark on branch ? Common pipistrelle T ? Soprano pipistrelle T PRF ivy on branch No data 114 PRF on stem 115 114 PRF on branch 119 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 116 116 PRF a rot-hollow on stem No data 116 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 117 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 118 118 PRF loose bark No data 118 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 120 120 PRF a rot-hollow on branch No data 120 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 121 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 122 122 PRF loose-bark on branch No data 122 PRF ivy on branch No data PRF host-tree alive (limb holding PRF may be dead) 124 PRF host-tree dead 143 124 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 125 124 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 134 PRF on stem 126 PRF on branch 130 126 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m height) 126 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 127 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m height) PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 128 128 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T

__________________________________________________________________________________________ B6 - 67

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Soprano pipistrelle T 129 Soprano pipistrelle T No data Leisler’s bat T/H (not below 9.5 m) Noctule Pm/T/H (not below 4.6 m height) 130 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 131 PRF a rot-hollow on branch Leisler’s bat T/H (not below 9.5 m) Noctule Sm/T (not below 4.6 m height) PRF a transverse crack, longitudinal split, loose bark or ivy on branch 132 132 PRF a transverse crack, longitudinal split or crevice on branch Leisler’s bat T/H (not below 9.5 m) Common pipistrelle T Soprano pipistrelle T 132 PRF loose-bark or ivy on branch 133 PRF loose-bark on branch Soprano pipistrelle T PRF ivy on branch No data 134 PRF on stem 135 134 PRF on branch 139 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 136 136 PRF a rot-hollow on stem No data 136 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 137 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 138 138 PRF loose bark No data 138 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 140 140 PRF a rot-hollow on branch No data 140 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 141 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 142 142 PRF loose-bark on branch No data 142 PRF ivy on branch No data Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 144 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/of  a distance from the PFR to the nearest obstacle beneath < 1 m 153 144 PRF on stem 145 144 PRF on branch 149 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 146 146 PRF a rot-hollow on stem Noctule Sm/T (not below 4.6 m height) 146 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 147 PRF a transverse crack, longitudinal split or crevice on stem Soprano pipistrelle T PRF loose bark or ivy on stem 148 148 PRF loose bark Soprano pipistrelle T 148 PRF ivy No data PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 150 150 PRF a rot-hollow on branch Noctule Sm/T (not below 4.6 m height) 150 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 151 PRF a transverse crack, longitudinal split or crevice on branch Soprano pipistrelle T

128 PRF loose bark or ivy on stem 129 PRF loose bark 129 PRF ivy 130 PRF a woodpecker-hollow on branch

131 131

133 133

135 135

137 137

139 139

141 141

143

145 145

147 147

149 149

151

__________________________________________________________________________________________ B6 - 68

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 151 PRF loose-bark or ivy on branch 152 152 PRF loose-bark on branch Soprano pipistrelle T 152 PRF ivy on branch No data 153 PRF on stem 154 153 PRF on branch 158 154 PRF a woodpecker-hollow on stem No data 154 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 155 155 PRF a rot-hollow on stem No data 155 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 156 156 PRF a transverse crack, longitudinal split or crevice on stem No data 156 PRF loose bark or ivy on stem 157 157 PRF loose bark No data 157 PRF ivy No data 158 PRF a woodpecker-hollow on branch No data 158 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 159 159 PRF a rot-hollow on branch No data 159 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 160 160 PRF a transverse crack, longitudinal split or crevice on branch No data 160 PRF loose-bark or ivy on branch 161 161 PRF loose-bark on branch No data 161 PRF ivy on branch No data 162 Hedge having connectivity (in itself or via a network of linear features) with woodland within 500 m of PRF host-tree. 163 162 Hedge having no connectivity (or connectivity but with gaps greater than 20 m) with woodland, or no woodland within 500 m of PRF host-tree 182 163 PRF host-tree less than 100 m away from river, canal or large pond or lake 164 163 PRF host-tree more than 100 m away from river, canal or large pond or lake 173 164 PRF host-tree alive (limb holding PRF may be dead) 165 164 PRF host-tree dead 169 165 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 166 165 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 166 PRF a rot-hollow on stem Brown long-eared bat Pm/T/H 166 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 167 167 PRF a transverse crack, longitudinal split or crevice on stem Brown long-eared bat T/H 167 PRF loose bark or ivy on stem 168 168 PRF loose bark Brown long-eared bat Sm/T/H 168 PRF ivy No data 169 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 170 169 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 170 PRF a rot-hollow on stem ? Brown long-eared bat Pm/T/H 170 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 171 171 PRF a transverse crack, longitudinal split or crevice on stem ? Brown long-eared bat T/H 171 PRF loose bark or ivy on stem 172 172 PRF loose bark ? Brown long-eared bat Sm/T/H 172 PRF ivy No data 173 PRF host-tree alive (limb holding PRF may be dead) 174 173 PRF host-tree dead 178 174 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 175 174 High-clutter environment: __________________________________________________________________________________________ B6 - 69

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

175 175

177 177

179 179

181 181

183 183

185 185

187 187

189 189

191 191

193

 dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a rot-hollow on stem Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 176 176 PRF a transverse crack, longitudinal split or crevice on stem Brown long-eared bat T/H 176 PRF loose bark or ivy on stem 177 PRF loose bark Brown long-eared bat Sm/T/H PRF ivy No data 178 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 179 178 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a rot-hollow on stem Brown long-eared bat Pm/T/H PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 180 180 PRF a transverse crack, longitudinal split or crevice on stem Brown long-eared bat T/H 180 PRF loose bark or ivy on stem 181 PRF loose bark Brown long-eared bat Sm/T/H PRF ivy No data 182 PRF host-tree less than 100 m away from river, canal or large pond or lake 183 182 PRF host-tree more than 100 m away from river, canal or large pond or lake 192 PRF host-tree alive (limb holding PRF may be dead) 184 PRF host-tree dead 188 184 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 185 184 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 186 186 PRF a transverse crack, longitudinal split or crevice on stem No data 186 PRF loose bark or ivy on stem 187 PRF loose bark No data PRF ivy No data 188 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 189 188 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 190 190 PRF a transverse crack, longitudinal split or crevice on stem No data 190 PRF loose bark or ivy on stem 191 PRF loose bark No data PRF ivy No data 192 PRF host-tree alive (limb holding PRF may be dead) 193 192 PRF host-tree dead 197 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 194 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) No data 194 PRF a rot-hollow on stem No data 194 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 195

__________________________________________________________________________________________ B6 - 70

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 195 PRF a transverse crack, longitudinal split or crevice on stem 195 PRF loose bark or ivy on stem 196 PRF loose bark 196 PRF ivy 197 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 197 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 198 PRF a rot-hollow on stem 198 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 199 PRF a transverse crack, longitudinal split or crevice on stem 199 PRF loose bark or ivy on stem 200 PRF loose bark 200 PRF ivy

No data 196 No data No data

198

No data No data 199 No data 200 No data No data

KEY D Isolated trees: Individual or small groups of trees where the distance between the canopy and linear connecting habitat such as woodland edge, hedgerow, dyke, cutting, river or stream is 10 m or greater. 1 PRF above 1 m height 2 1 PRF below 1 m height 321 2 Broadleaved tree 3 2 Coniferous tree 162 3 Tree located < 100 m from woodland 4 3 Tree located > 100 m from woodland 83 4 PRF host-tree less than 100 m away from river, canal or large pond or lake 5 4 PRF host-tree more than 100 m away from river, canal or large pond or lake 44 5 PRF host-tree alive (limb holding PRF may be dead) 6 5 PRF host-tree dead 25 6 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 7 6 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 16 7 PRF on stem 8 7 PRF on branch 12 8 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 8 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 9 9 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 9 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 10 10 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture 10 PRF loose bark or ivy on stem 11 11 PRF loose bark No data 11 PRF ivy No data 12 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 12 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 13 13 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 13 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 14 14 PRF a transverse crack, longitudinal split or crevice on branch No data 14 PRF loose-bark or ivy on branch 15 __________________________________________________________________________________________ B6 - 71

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 15 15

17 17

19 19

21 21 22 22

24 24

26 26

28 28

30 30

32 32

34 34

36 36

38 38

PRF loose-bark on branch No data PRF ivy on branch No data 16 PRF on stem 17 16 PRF on branch 21 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 18 18 PRF a rot-hollow on stem No data 18 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 19 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 20 20 PRF loose bark No data 20 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 22 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, loose bark or ivy on branch 23 23 PRF a transverse crack, longitudinal split or crevice on branch No data 23 PRF loose-bark or ivy on branch 24 PRF loose-bark on branch No data PRF ivy on branch No data 25 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 26 25 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 35 PRF on stem 27 PRF on branch 31 27 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 27 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 28 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 29 29 PRF a transverse crack, longitudinal split or crevice on stem No data 29 PRF loose bark or ivy on stem 30 PRF loose bark No data PRF ivy No data 31 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 31 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 32 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, loose bark or ivy on branch 33 33 PRF a transverse crack, longitudinal split or crevice on branch No data 33 PRF loose-bark or ivy on branch 34 PRF loose-bark on branch No data PRF ivy on branch No data 35 PRF on stem 36 35 PRF on branch 40 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 37 37 PRF a rot-hollow on stem No data 37 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 38 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 39

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40 40

42 42

44 44

46 46

48 48

50 50

52 52

54 54

56 56

58 58

60 60

39 PRF loose bark No data 39 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 41 41 PRF a rot-hollow on branch No data 41 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 42 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 43 43 PRF loose-bark on branch No data 43 PRF ivy on branch No data PRF host-tree alive (limb holding PRF may be dead) 45 PRF host-tree dead 64 45 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 46 45 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 55 PRF on stem 47 PRF on branch 51 47 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 47 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 48 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 49 49 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture 49 PRF loose bark or ivy on stem 50 PRF loose bark No data PRF ivy No data 51 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 51 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 52 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, loose bark or ivy on branch 53 53 PRF a transverse crack, longitudinal split or crevice on branch No data 53 PRF loose-bark or ivy on branch 54 PRF loose-bark on branch No data PRF ivy on branch No data 55 PRF on stem 56 55 PRF on branch 60 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 57 57 PRF a rot-hollow on stem No data 57 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 58 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 59 59 PRF loose bark No data 59 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 61 61 PRF a rot-hollow on branch No data 61 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 62 PRF a transverse crack, longitudinal split or crevice on branch No data

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 62

66 66

68 68

70 70

72 72

74 74

76 76

78 78

80 80

82 82

84 84

PRF loose-bark or ivy on branch 63 63 PRF loose-bark on branch No data 63 PRF ivy on branch No data Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 65 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 74 65 PRF on stem 66 65 PRF on branch 70 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 67 67 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 67 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 68 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 69 69 PRF loose bark No data 69 PRF ivy No data PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 71 71 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 71 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 72 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 73 73 PRF loose-bark on branch No data 73 PRF ivy on branch No data PRF on stem 75 PRF on branch 79 75 PRF a woodpecker-hollow on stem No data 75 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 76 PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 77 77 PRF a transverse crack, longitudinal split or crevice on stem No data 77 PRF loose bark or ivy on stem 78 PRF loose bark No data PRF ivy No data 79 PRF a woodpecker-hollow on branch No data 79 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 80 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, loose bark or ivy on branch 81 81 PRF a transverse crack, longitudinal split or crevice on branch No data 81 PRF loose-bark or ivy on branch 82 PRF loose-bark on branch No data PRF ivy on branch No data 83 PRF host-tree less than 100 m away from river, canal or large pond or lake 84 83 PRF host-tree more than 100 m away from river, canal or large pond or lake 123 PRF host-tree alive (limb holding PRF may be dead) 85 PRF host-tree dead 104 85 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and

__________________________________________________________________________________________ B6 - 74

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 

a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 86 85 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 95 86 PRF on stem 87 86 PRF on branch 91 87 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 87 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 88 88 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 88 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 89 89 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture 89 PRF loose bark or ivy on stem 90 90 PRF loose bark No data 90 PRF ivy No data 91 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 91 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 92 92 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 92 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 93 93 PRF a transverse crack, longitudinal split or crevice on branch No data 93 PRF loose-bark or ivy on branch 94 94 PRF loose-bark on branch No data 94 PRF ivy on branch No data 95 PRF on stem 96 95 PRF on branch 100 96 PRF a woodpecker-hollow on stem No data 96 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 97 97 PRF a rot-hollow on stem No data 97 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 98 98 PRF a transverse crack, longitudinal split or crevice on stem No data 98 PRF loose bark or ivy on stem 99 99 PRF loose bark No data 99 PRF ivy No data 100 PRF a woodpecker-hollow on branch No data 100 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 101 101 PRF a rot-hollow on branch No data 101 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 102 102 PRF a transverse crack, longitudinal split or crevice on branch No data 102 PRF loose-bark or ivy on branch 103 103 PRF loose-bark on branch No data 103 PRF ivy on branch No data 104 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 105 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 114 105 PRF on stem 106 105 PRF on branch 110 106 PRF a woodpecker-hollow on stem __________________________________________________________________________________________ B6 - 75

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 106 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 107 107 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 107 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 108 108 PRF a transverse crack, longitudinal split or crevice on stem No data 108 PRF loose bark or ivy on stem 109 109 PRF loose bark No data 109 PRF ivy No data 110 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 110 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 111 111 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 111 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 112 112 PRF a transverse crack, longitudinal split or crevice on branch No data 112 PRF loose-bark or ivy on branch 113 113 PRF loose-bark on branch No data 113 PRF ivy on branch No data 114 PRF on stem 115 114 PRF on branch 119 115 PRF a woodpecker-hollow on stem No data 115 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 116 116 PRF a rot-hollow on stem No data 116 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 117 117 PRF a transverse crack, longitudinal split or crevice on stem No data 117 PRF loose bark or ivy on stem 118 118 PRF loose bark No data 118 PRF ivy No data 119 PRF a woodpecker-hollow on branch No data 119 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 120 120 PRF a rot-hollow on branch No data 120 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 121 121 PRF a transverse crack, longitudinal split or crevice on branch No data 121 PRF loose-bark or ivy on branch 122 122 PRF loose-bark on branch No data 122 PRF ivy on branch No data 123 PRF host-tree alive (limb holding PRF may be dead) 124 123 PRF host-tree dead 143 124 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 125 124 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 134 125 PRF on stem 126 125 PRF on branch 130 126 PRF a woodpecker-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 126 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 127 127 PRF a rot-hollow on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 127 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 128 128 PRF a transverse crack, longitudinal split or crevice on stem Leisler’s bat T/H (not below 9.5 m) – Parkland, pasture 128 PRF loose bark or ivy on stem 129 __________________________________________________________________________________________ B6 - 76

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

130 130

132 132

134 134

136 136

138 138

140 140

142 142

144 144

146 146

148 148

150 150

129 PRF loose bark No data 129 PRF ivy No data PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 131 131 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 131 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 132 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 133 133 PRF loose-bark on branch No data 133 PRF ivy on branch No data PRF on stem 135 PRF on branch 139 135 PRF a woodpecker-hollow on stem No data 135 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 136 PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 137 137 PRF a transverse crack, longitudinal split or crevice on stem No data 137 PRF loose bark or ivy on stem 138 PRF loose bark No data PRF ivy No data 139 PRF a woodpecker-hollow on branch No data 139 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 140 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, loose bark or ivy on branch 141 141 PRF a transverse crack, longitudinal split or crevice on branch No data 141 PRF loose-bark or ivy on branch 142 PRF loose-bark on branch No data PRF ivy on branch No data 143 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 144 143 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 153 PRF on stem 145 PRF on branch 149 145 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 145 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 146 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 147 147 PRF a transverse crack, longitudinal split or crevice on stem No data 147 PRF loose bark or ivy on stem 148 PRF loose bark No data PRF ivy No data 149 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 149 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 150 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, loose bark or ivy on branch 151 151 PRF a transverse crack, longitudinal split or crevice on branch No data 151 PRF loose-bark or ivy on branch 152

__________________________________________________________________________________________ B6 - 77

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 152 PRF loose-bark on branch No data 152 PRF ivy on branch No data 153 PRF on stem 154 153 PRF on branch 158 154 PRF a woodpecker-hollow on stem No data 154 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 155 155 PRF a rot-hollow on stem No data 155 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 156 156 PRF a transverse crack, longitudinal split or crevice on stem No data 156 PRF loose bark or ivy on stem 157 157 PRF loose bark No data 157 PRF ivy No data 158 PRF a woodpecker-hollow on branch No data 158 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 159 159 PRF a rot-hollow on branch No data 159 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 160 160 PRF a transverse crack, longitudinal split or crevice on branch No data 160 PRF loose-bark or ivy on branch 161 161 PRF loose-bark on branch No data 161 PRF ivy on branch No data 162 Tree located < 100 m from woodland 163 162 Tree located > 100 m from woodland 242 163 PRF host-tree less than 100 m away from river, canal or large pond or lake 164 163 PRF host-tree more than 100 m away from river, canal or large pond or lake 203 164 PRF host-tree alive (limb holding PRF may be dead) 165 164 PRF host-tree dead 184 165 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 166 165 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 175 166 PRF on stem 167 166 PRF on branch 171 167 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 167 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 168 168 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 168 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 169 169 PRF a transverse crack, longitudinal split or crevice on stem No data 169 PRF loose bark or ivy on stem 170 170 PRF loose bark No data 170 PRF ivy No data 171 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 171 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 172 172 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 172 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 173 173 PRF a transverse crack, longitudinal split or crevice on branch No data 173 PRF loose-bark or ivy on branch 174 174 PRF loose-bark on branch No data 174 PRF ivy on branch No data 175 PRF on stem 176 175 PRF on branch 180 __________________________________________________________________________________________ B6 - 78

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 176 PRF a woodpecker-hollow on stem No data 176 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 177 177 PRF a rot-hollow on stem No data 177 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 178 178 PRF a transverse crack, longitudinal split or crevice on stem No data 178 PRF loose bark or ivy on stem 179 179 PRF loose bark No data 179 PRF ivy No data 180 PRF a woodpecker-hollow on branch No data 180 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 181 181 PRF a rot-hollow on branch No data 181 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 182 182 PRF a transverse crack, longitudinal split or crevice on branch No data 182 PRF loose-bark or ivy on branch 183 183 PRF loose-bark on branch No data 183 PRF ivy on branch No data 184 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 185 184 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 194 185 PRF on stem 186 185 PRF on branch 190 186 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 186 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 187 187 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 187 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 188 188 PRF a transverse crack, longitudinal split or crevice on stem No data 188 PRF loose bark or ivy on stem 189 189 PRF loose bark No data 189 PRF ivy No data 190 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 190 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 191 191 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 191 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 192 192 PRF a transverse crack, longitudinal split or crevice on branch No data 192 PRF loose-bark or ivy on branch 193 193 PRF loose-bark on branch No data 193 PRF ivy on branch No data 194 PRF on stem 195 194 PRF on branch 199 195 PRF a woodpecker-hollow on stem No data 195 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 196 196 PRF a rot-hollow on stem No data 196 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 197 197 PRF a transverse crack, longitudinal split or crevice on stem No data 197 PRF loose bark or ivy on stem 198 198 PRF loose bark No data 198 PRF ivy No data 199 PRF a woodpecker-hollow on branch No data 199 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 200 __________________________________________________________________________________________ B6 - 79

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 200 PRF a rot-hollow on branch No data 200 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 201 201 PRF a transverse crack, longitudinal split or crevice on branch No data 201 PRF loose-bark or ivy on branch 202 202 PRF loose-bark on branch No data 202 PRF ivy on branch No data 203 PRF host-tree alive (limb holding PRF may be dead) 204 203 PRF host-tree dead 223 204 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 205 204 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 214 205 PRF on stem 206 205 PRF on branch 210 206 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 206 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 207 207 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 207 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 208 208 PRF a transverse crack, longitudinal split or crevice on stem No data 208 PRF loose bark or ivy on stem 209 209 PRF loose bark No data 209 PRF ivy No data 210 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 210 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 211 211 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 211 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 212 212 PRF a transverse crack, longitudinal split or crevice on branch No data 212 PRF loose-bark or ivy on branch 213 213 PRF loose-bark on branch No data 213 PRF ivy on branch No data 214 PRF on stem 215 214 PRF on branch 219 215 PRF a woodpecker-hollow on stem No data 215 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 216 216 PRF a rot-hollow on stem No data 216 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 217 217 PRF a transverse crack, longitudinal split or crevice on stem No data 217 PRF loose bark or ivy on stem 218 218 PRF loose bark No data 218 PRF ivy No data 219 PRF a woodpecker-hollow on branch No data 219 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 220 220 PRF a rot-hollow on branch No data 220 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 221 221 PRF a transverse crack, longitudinal split or crevice on branch No data 221 PRF loose-bark or ivy on branch 222 222 PRF loose-bark on branch No data 222 PRF ivy on branch No data 223 Low-clutter environment:  no (or low density) shrub layer; __________________________________________________________________________________________ B6 - 80

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________  

224 224

226 226

228 228

230 230

232 232

234 234

236 236

238 238

240 240

242 242

244

no/light obstructing/overhanging foliage (crack willow etc.); and a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 224 223 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 233 PRF on stem 225 PRF on branch 229 225 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 225 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 226 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 227 227 PRF a transverse crack, longitudinal split or crevice on stem No data 227 PRF loose bark or ivy on stem 228 PRF loose bark No data PRF ivy No data 229 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 229 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 230 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, loose bark or ivy on branch 231 231 PRF a transverse crack, longitudinal split or crevice on branch No data 231 PRF loose-bark or ivy on branch 232 PRF loose-bark on branch No data PRF ivy on branch No data 233 PRF on stem 234 233 PRF on branch 238 PRF a woodpecker-hollow on stem No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 235 235 PRF a rot-hollow on stem No data 235 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 236 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 237 237 PRF loose bark No data 237 PRF ivy No data PRF a woodpecker-hollow on branch No data PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 239 239 PRF a rot-hollow on branch No data 239 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 240 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 241 241 PRF loose-bark on branch No data 241 PRF ivy on branch No data PRF host-tree less than 100 m away from river, canal or large pond or lake 243 PRF host-tree more than 100 m away from river, canal or large pond or lake 282 243 PRF host-tree alive (limb holding PRF may be dead) 244 243 PRF host-tree dead 263 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 245 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or

__________________________________________________________________________________________ B6 - 81

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

246 246

248 248

250 250

252 252

254 254

256 256

258 258

260 260

262 262

264 264

266 266

 a distance from the PFR to the nearest obstacle beneath < 1 m 254 245 PRF on stem 246 245 PRF on branch 250 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 247 247 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 247 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 248 PRF a transverse crack, longitudinal split or crevice on stem No data PRF loose bark or ivy on stem 249 249 PRF loose bark No data 249 PRF ivy No data PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 251 251 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 251 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 252 PRF a transverse crack, longitudinal split or crevice on branch No data PRF loose-bark or ivy on branch 253 253 PRF loose-bark on branch No data 253 PRF ivy on branch No data PRF on stem 255 PRF on branch 259 255 PRF a woodpecker-hollow on stem No data 255 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 256 PRF a rot-hollow on stem No data PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 257 257 PRF a transverse crack, longitudinal split or crevice on stem No data 257 PRF loose bark or ivy on stem 258 PRF loose bark No data PRF ivy No data 259 PRF a woodpecker-hollow on branch No data 259 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 260 PRF a rot-hollow on branch No data PRF a transverse crack, longitudinal split, loose bark or ivy on branch 261 261 PRF a transverse crack, longitudinal split or crevice on branch No data 261 PRF loose-bark or ivy on branch 262 PRF loose-bark on branch No data PRF ivy on branch No data 263 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 264 263 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 273 PRF on stem 265 PRF on branch 269 265 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 265 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 266 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 267 267 PRF a transverse crack, longitudinal split or crevice on stem No data

__________________________________________________________________________________________ B6 - 82

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 267 PRF loose bark or ivy on stem 268 268 PRF loose bark No data 268 PRF ivy No data 269 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 269 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 270 270 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 270 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 271 271 PRF a transverse crack, longitudinal split or crevice on branch No data 271 PRF loose-bark or ivy on branch 272 272 PRF loose-bark on branch No data 272 PRF ivy on branch No data 273 PRF on stem 274 273 PRF on branch 278 274 PRF a woodpecker-hollow on stem No data 274 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 275 275 PRF a rot-hollow on stem No data 275 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 276 276 PRF a transverse crack, longitudinal split or crevice on stem No data 276 PRF loose bark or ivy on stem 277 277 PRF loose bark No data 277 PRF ivy No data 278 PRF a woodpecker-hollow on branch No data 278 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 279 279 PRF a rot-hollow on branch No data 279 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 280 280 PRF a transverse crack, longitudinal split or crevice on branch No data 280 PRF loose-bark or ivy on branch 281 281 PRF loose-bark on branch No data 281 PRF ivy on branch No data 282 PRF host-tree alive (limb holding PRF may be dead) 283 282 PRF host-tree dead 302 283 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 284 283 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 293 284 PRF on stem 285 284 PRF on branch 289 285 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 285 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 286 286 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 286 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 287 287 PRF a transverse crack, longitudinal split or crevice on stem No data 287 PRF loose bark or ivy on stem 288 288 PRF loose bark No data 288 PRF ivy No data 289 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 289 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 290 290 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village __________________________________________________________________________________________ B6 - 83

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 290 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 291 291 PRF a transverse crack, longitudinal split or crevice on branch No data 291 PRF loose-bark or ivy on branch 292 292 PRF loose-bark on branch No data 292 PRF ivy on branch No data 293 PRF on stem 294 293 PRF on branch 298 294 PRF a woodpecker-hollow on stem No data 294 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 295 295 PRF a rot-hollow on stem No data 295 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 296 296 PRF a transverse crack, longitudinal split or crevice on stem No data 296 PRF loose bark or ivy on stem 297 297 PRF loose bark No data 297 PRF ivy No data 298 PRF a woodpecker-hollow on branch No data 298 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 299 299 PRF a rot-hollow on branch No data 299 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 300 300 PRF a transverse crack, longitudinal split or crevice on branch No data 300 PRF loose-bark or ivy on branch 301 301 PRF loose-bark on branch No data 301 PRF ivy on branch No data 302 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.); and  a distance between the PRF to the nearest obstacle beneath (ground, branch, shrub layer etc.) > 1 m 303 302 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.); and/or  a distance from the PFR to the nearest obstacle beneath < 1 m 312 303 PRF on stem 304 303 PRF on branch 308 304 PRF a woodpecker-hollow on stem Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 304 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on stem 305 305 PRF a rot-hollow on stem Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 305 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 306 306 PRF a transverse crack, longitudinal split or crevice on stem No data 306 PRF loose bark or ivy on stem 307 307 PRF loose bark No data 307 PRF ivy No data 308 PRF a woodpecker-hollow on branch Noctule Pm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 308 PRF a rot-hollow, transverse crack, longitudinal split, crevice, loose bark or ivy on branch 309 309 PRF a rot-hollow on branch Noctule Sm/T/H (not below 4.6 m height) – Parkland, pasture, rural village 309 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 310 310 PRF a transverse crack, longitudinal split or crevice on branch No data 310 PRF loose-bark or ivy on branch 311 311 PRF loose-bark on branch No data 311 PRF ivy on branch No data 312 PRF on stem 313 312 PRF on branch 317 313 PRF a woodpecker-hollow on stem No data 313 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on stem 314 314 PRF a rot-hollow on stem No data __________________________________________________________________________________________ B6 - 84

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 314 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 315 PRF a transverse crack, longitudinal split or crevice on stem 315 PRF loose bark or ivy on stem 316 PRF loose bark 316 PRF ivy 317 PRF a woodpecker-hollow on branch 317 PRF rot-hollow, transverse crack, longitudinal split, crevice, bark or ivy on branch 318 PRF a rot-hollow on branch 318 PRF a transverse crack, longitudinal split, loose bark or ivy on branch 319 PRF a transverse crack, longitudinal split or crevice on branch 319 PRF loose-bark or ivy on branch 320 PRF loose-bark on branch 320 PRF ivy on branch 321 Broadleaved tree 321 Coniferous tree 322 Tree located < 100 m from woodland 322 Tree located > 100 m from woodland 323 PRF host-tree less than 100 m away from river, canal or large pond or lake 323 PRF host-tree more than 100 m away from river, canal or large pond or lake 324 PRF host-tree alive (limb holding PRF may be dead) 324 PRF host-tree dead 325 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 325 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 326 PRF a rot-hollow on stem 326 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 327 PRF a transverse crack, longitudinal split or crevice on stem 327 PRF loose bark or ivy on stem 328 PRF loose bark 328 PRF ivy 329 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 329 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 330 PRF a rot-hollow on stem 330 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 331 PRF a transverse crack, longitudinal split or crevice on stem 331 PRF loose bark or ivy on stem 332 PRF loose bark 332 PRF ivy 333 PRF host-tree alive (limb holding PRF may be dead) 333 PRF host-tree dead 334 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 334 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 335 PRF a rot-hollow on stem 335 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 336 PRF a transverse crack, longitudinal split or crevice on stem 336 PRF loose bark or ivy on stem 337 PRF loose bark

315 No data 316 No data No data No data 318 No data 319 No data 320 No data No data 322 361 323 342 324 333 325 329

326

No data No data 327 No data 328 No data No data

330

No data No data 331 No data 332 No data No data 334 338

335

No data No data 336 No data 337 No data

__________________________________________________________________________________________ B6 - 85

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 337 PRF ivy 338 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 338 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 339 PRF a rot-hollow on stem 339 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 340 PRF a transverse crack, longitudinal split or crevice on stem 340 PRF loose bark or ivy on stem 341 PRF loose bark 341 PRF ivy 342 PRF host-tree less than 100 m away from river, canal or large pond or lake 342 PRF host-tree more than 100 m away from river, canal or large pond or lake 343 PRF host-tree alive (limb holding PRF may be dead) 343 PRF host-tree dead 344 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 344 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 345 PRF a rot-hollow on stem 345 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 346 PRF a transverse crack, longitudinal split or crevice on stem 346 PRF loose bark or ivy on stem 347 PRF loose bark 347 PRF ivy 348 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 348 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 349 PRF a rot-hollow on stem 349 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 350 PRF a transverse crack, longitudinal split or crevice on stem 350 PRF loose bark or ivy on stem 351 PRF loose bark 351 PRF ivy 352 PRF host-tree alive (limb holding PRF may be dead) 352 PRF host-tree dead 353 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 353 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 354 PRF a rot-hollow on stem 354 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 355 PRF a transverse crack, longitudinal split or crevice on stem 355 PRF loose bark or ivy on stem 356 PRF loose bark 356 PRF ivy 357 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.)

No data

339

No data No data 340 No data 341 No data No data 343 352 344 348

345

No data No data 346 No data 347 No data No data

349

No data No data 350 No data 351 No data No data 353 357

354

No data No data 355 No data 356 No data No data

358

__________________________________________________________________________________________ B6 - 86

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 357 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 358 PRF a rot-hollow on stem 358 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 359 PRF a transverse crack, longitudinal split or crevice on stem 359 PRF loose bark or ivy on stem 360 PRF loose bark 360 PRF ivy 361 Tree located < 100 m from woodland 361 Tree located > 100 m from woodland 362 PRF host-tree less than 100 m away from river, canal or large pond or lake 362 PRF host-tree more than 100 m away from river, canal or large pond or lake 363 PRF host-tree alive (limb holding PRF may be dead) 363 PRF host-tree dead 364 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 364 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 365 PRF a rot-hollow on stem 365 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 366 PRF a transverse crack, longitudinal split or crevice on stem 366 PRF loose bark or ivy on stem 367 PRF loose bark 367 PRF ivy 368 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 368 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 369 PRF a rot-hollow on stem 369 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 370 PRF a transverse crack, longitudinal split or crevice on stem 370 PRF loose bark or ivy on stem 371 PRF loose bark 371 PRF ivy 372 PRF host-tree alive (limb holding PRF may be dead) 372 PRF host-tree dead 373 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 373 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 374 PRF a rot-hollow on stem 374 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 375 PRF a transverse crack, longitudinal split or crevice on stem 375 PRF loose bark or ivy on stem 376 PRF loose bark 376 PRF ivy 377 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 377 High-clutter environment:  dense shrub layer; and / or

No data No data 359 No data 360 No data No data 362 381 363 372 364 368

365

No data No data 366 No data 367 No data No data

369

No data No data 370 No data 371 No data No data 373 377

374

No data No data 375 No data 376 No data No data

378

__________________________________________________________________________________________ B6 - 87

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Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________

379 379

381 381

383

385 385

387

389 389

391 391

393 393

395 395

397 397

 dense obstructing/overhanging foliage (horse chestnut etc.) 378 PRF a rot-hollow on stem 378 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem PRF a transverse crack, longitudinal split or crevice on stem PRF loose bark or ivy on stem 380 PRF loose bark 380 PRF ivy PRF host-tree less than 100 m away from river, canal or large pond or lake PRF host-tree more than 100 m away from river, canal or large pond or lake 382 PRF host-tree alive (limb holding PRF may be dead) 382 PRF host-tree dead Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 384 PRF a rot-hollow on stem 384 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem PRF a transverse crack, longitudinal split or crevice on stem PRF loose bark or ivy on stem 386 PRF loose bark 386 PRF ivy Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) 388 PRF a rot-hollow on stem 388 PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem PRF a transverse crack, longitudinal split or crevice on stem PRF loose bark or ivy on stem 390 PRF loose bark 390 PRF ivy PRF host-tree alive (limb holding PRF may be dead) PRF host-tree dead 392 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 392 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) PRF a rot-hollow on stem PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 394 PRF a transverse crack, longitudinal split or crevice on stem 394 PRF loose bark or ivy on stem PRF loose bark PRF ivy 396 Low-clutter environment:  no (or low density) shrub layer;  no/light obstructing/overhanging foliage (crack willow etc.) 396 High-clutter environment:  dense shrub layer; and / or  dense obstructing/overhanging foliage (horse chestnut etc.) PRF a rot-hollow on stem PRF a transverse crack, longitudinal split, crevice, loose bark or ivy on stem 398 PRF a transverse crack, longitudinal split or crevice on stem

No data No data 379 No data 380 No data No data 382 391 383 387

384

No data No data 385 No data 386 No data No data

388

No data No data 389 No data 390 No data No data 392 396

393

No data No data 394 No data 395 No data No data

397

No data No data 398 No data

__________________________________________________________________________________________ B6 - 88

BAT TREE HABITAT KEY

Section B. BATS Chapter B6 – Bat Tree Habitat Key __________________________________________________________________________________________ 398 PRF loose bark or ivy on stem 399 PRF loose bark 399 PRF ivy

399 No data No data

_______________________________________

__________________________________________________________________________________________ B6 - 89

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Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

REFERENCES AA 1973. Book of the British Countryside. Drive Publication Limited, London. Ackers C 1938. Practical British Forestry. Oxford University Press, London. Alexander K 2011. Why dead and decaying trees are important in: Milner E 2011. TREES of BRITAIN and IRELAND. Natural History Museum, London. Altringham J 1999. Bats: Biology and Behaviour. Oxford University Press, Oxford. Altringham J 2003. British Bats. Collins New Naturalist series No 93, Harper Collins, London. Altringham J 2011. Bats: From Evolution to Conservation (2nd Edition). Oxford University Press, Oxford. Arnold A, Braun M, Becker N & Stoch V 1998. Beitrag zur Ökologie der Wasserfledermaus (Myotis daubentonii) in Norbaden. Carolinea 56: 103-110. Baldwin E 1993. Leader breakage in upland Sitka spruce plantations. Scottish Forestry 47: 25-29. Barrett-Hamilton G 1910. A History of British Mammals: Vol. 1 – Bats. Gurney & Jackson, London. Bauer K & Walter W 1977. Bechsteinfledermaus (Myotis bechsteinii) und Kleinabensegler (Nyctalus leisleri), zwei bemerkenswerre Arten der steirschen Säugetierfauna. Mitt. Abt. Zool. Landsemus. Joanneum 6(1): 1-8 Beck A & Schort W 2005. Baumhöhlenquartiere des Kleinabendseglers (Nyctalus leisleri) in Südthüringen und der Nordschweiz. Nyctalus (N.F.). 10: 250-254. Billington G 2004. The use of tree roosts by barbastelle bats. Oral presentation at ‘Managing Trees and Woodlands as Habitat for Bats’ Conference, Bournemouth University. Bisch J & Auclair D 1988. Influence of silvicultural treatment (high forest or coppice-withstandards) on oak above-ground biomass distribution in central France. Forestry 61: 205217. Cited in: Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Boddy L & Rayner A 1983. Origins of decay in living deciduous trees: the role of moisture content and a re-appraisal of the expanded concept of tree decay. New Phytol 94: 623641. Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Bonham H 1934. Aids to Botany. Bailière, Tindall & Cox, London. Boonman M 2000. Roost selection by noctules (Nyctalus noctula) and Daubenton’s bats (Myotis daubentonii). J. Zool. 251: 385-389 Böttcher P & Liese W 1975. Zur Verkernung des Wurzelholzes von Fichte und Lärche. Forstw. Cbl. 94: 152-160. Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Boye P & Dietz M 2005. Development of good practice guidelines for Woodland Management for Bats. English Nature research reports No. 661, Natural England Peterborough. BRE 1998. Timbers: their natural durability and resistance to preservative treatment. Building Research Establishment: Digest 429. Bristowe W 1971. The World of Spiders. Collins New Naturalist Series, Collins, London. Burton M 1968. Wild Animals of the British Isles. Frederic Warne & Co. Ltd, London.

__________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Butler C 2003. Population biology of the introduced Rose-ringed parakeet Psittacula krameri in the UK. PhD thesis, Department of Zoology, Edward Grey Institute of Field Ornithology, University of Oxford. Cady M & Hume R 1988. AA/RSPB Complete Book of British Birds. AA, Basingstoke, RSPB, Sandy. Campbell B 1953. Finding Nests. Collins, London. Cartwright M & Findlay W 1958. Decay of Timber and its Prevention. Her Majesty’s Stationary Office, London. Catherine C & Amphlett A 2011. Deadwood: Importance and Management. In Practice – Bulletin of the Institute of Ecology and Environmental Management: September 11-15. Červený J & Bürger P 1989. Density & structure of the bat community occupying an old park at Žihobce (Czechoslovakia). In: Hanák V, Horáček I & Gaisler J (eds.) 1989. EUROPEAN BAT RESEARCH 1987. Charles Univ. Press, Praha. Cramp S (ed.) 1985. The Birds of the Western Palearctic, Vol. IV. RSPB – Oxford University Press, Oxford. Cramp S & Simmons K (eds.) 1979. The Birds of the Western Palearctic, Vol. II. RSPB – Oxford University Press, Oxford. Cramp C, Brooks D, Dunn E, Gillmor R, Hollom P, Hudson R, Nicholson E, Ogilvie M, Olney P, Roselaar C, Simmons K, Voous K, Wallace D, Wattel J & Wilson M 1985. Handbook of the Birds of Europe the Middle East and North Africa. The Birds of the Western Palearctic. Volume IV – Terns to Woodpeckers. Oxford University Press. Davidson-Watts I & Jones G 2006. Differences in foraging behaviour between Pipistrellus pipistrellus and Pipistrellus pygmaeus. J. Zool. Lond., 268: 55-62. De Jong J 1994. Habitat use, home-range and activity pattern of the northern bat, Eptesicus nilsonni, in a hemiboreal coniferous forest. Mammalia 58: 535-548 Cited in: Shiel C, Shiel R & Fairley J 1999. Seasonal changes in the foraging behaviour of Leisler’s bats (Nyctalus leisleri) in Ireland as revealed by radio-telemetry. J. Zool. Lond., 249(3): 347358. Dense C & Rahmel U 2002. Untersuchungen zur Habitatnutzung der GroBen Bartfledermaus (Myotis brandtdii) im nordwestlichen Niedersachsen. In: MESCHEDE, A., HELLER, K.-G. & BOYE, P. eds. Okolgie, Wanderungen und Genetik von Fledermausen in Waldern – Untersuchungen als Grundlage fur den Fledermausschutz, 51-68. Munster: Landsirtschaftsverlag. Cited in: Harris S & Yalden D (eds.) 2008. Mammals of the British Isles: Handbook, 4th Edition. The Mammal Society, London. Dietz M & Boye P 2004. Myotis daubentonii (Kuhl 1817). In: Petersen B et al. (eds.) Das europäische Schutzgebietssystem Natura 2000. Ökologie und Verbreitung von Arten der FFH-Richtlinie in Deutschland. Munster: Landwirtschartsverlag. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Dietz C, Helversen O & Dietmar N 2011. Bats of Britain, Europe & Northwest Africa. A & C Black, London. Dietz M & Pir J 2009. Distribution and habitat Selection of Myotis bechsteinii Kuhl, 1817 (Chirptera, Vespertilionidae) in Luxemburg – Implications for Forest Management and Conservation. Folia Zoologica 58 (3): 327-340 Cited in: Dietz M & Pir J 2011. Distribution, Ecology and Habitat Selection by Bechstein’s bat (Myotis bechsteinii) in Luxembourg. Ökologie der Säugetiere 6. Dietz M & Pir J 2011. Distribution, Ecology and Habitat Selection by Bechstein’s bat (Myotis bechsteinii) in Luxembourg. Ökologie der Säugetiere 6. __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Desch H & Dinwoodie J 1996. Timber: Structure, Propoties, Conversion and Use (7th Edition). Palgrave, Macmillan. Douglas G 1995. Prospects for advanced vegetative propagation and genetic modification of forest species In: Pilcher J & Mac an tSaoir S (eds.) 1995. Wood, trees and forests in Ireland. 1 – 12. Royal Irish Academy, Dublin. Edlin H 1944. British Woodland Trees. B. T. Batsford Ltd, London. Edlin H 1956. Trees, Woods & Man. Collins New Naturalist Series, Collins, London. Edlin H 1976. Forestry Commission Booklet No. 15. Know your conifers (Fourth Impression). HMSO, London. Egsbaek W, Kirk K & Roer H 1971. Beringungsergebnisse der Wasserfledermaus (Myotis daubentoni) und der Teichfledermaus (Myotis dasycneme) in Jütland. – DechenianaBeihefte 18: 51-55. Ekman M & De Jong J 1996. Local patterns of distribution and resource utilization of four bat species (Myotis brandtii, Epesicus nilssoni, Plecotus auritus and Pipistrellus pipistrellus) in patchy and continuous environments. J. Zool. 238: 571-580. Entwistle A 1994. Roost Ecology of the brown long-eared bat (Plecotus auritus, Linnaeus 1758) in north-east Scotland. PhD thesis, University of Aberdeen. Cited in: Harris S & Yalden D (eds.) 2008. Mammals of the British Isles: Handbook, 4th Edition. The Mammal Society, London. Entwistle A, Racey P & Speakman J 1996. Habitat exploitation by a gleaning bat, Plecotus auritus. Philosophical Transactions of the Royal Society of London Series B, 351(1342): 921-931. Entwistle A, Racey P & Speakman J 1997. Roost selection by the brown long-eared bat (Plecotus auritus). Journal of Applied Ecology 34:399-408. Evelyn J 1664. Sylva, or A Discourse of Forest-Trees and the Propagation of Timber in His Majesty's Dominions. 1st Ed. Royal Society, London. Ferguson-Lees J, Castell R & Leech D 2011. A field guide to monitoring nests. British Trust for Ornithology. Flanders J & Hill D 2004. Selection of maternity roosts by Bechstein's bats. Oral presentation at ‘Managing Trees and Woodlands as Habitat for Bats’ Conference, Bournemouth University. Forestry Commission for England & Wales, Bat Conservation Trust, Countryside Council for Wales & English Nature 2005. Woodland Management for Bats. Forestry Commission Publications. Fuhrmann M 1991. Untersuchungen zur Biologie des Braunen Langohrs (Plecotus auritus L., 1758) im Lennebergwald bei Mainz. Diploma thesis: University of Mainz. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Fuhrmann M & Godmann O 1991. Naturliche quartiere de waldflederemause schutzen! Konsequenzen au seiner Baumhohlenuntersuchung in Rheingau. AFZ-Allgemine-Forst Zeitschrift 49(19): 982-983. Fuhrmann M & Godmann O 1994. Baumhöhlenquartiere vom Braunen Langohr und von der Bechseinfledermaus: Ergebnisse einer telemtrishcen Untersuchung. In: AGFH ed. :Die Fledermäuse Hessens 181-186. Remshalden-Buoch: Verlag Manfred Hennecke. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for Woodland Management for Bats. English Nature research reports No. 661, Natural England Peterborough. Fuhrmann M & Seitz A 1992. Nocturnal activity of the brown long-eared bat (Plecotus auritus L. 1758): data from radio-tracking in the Lenneburg Forest near Mainz __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

(Germany). In: Priede I & Swift S (eds.) 1992. Wildlife telemetry: Remote Monitoring and Tracking of Animals. Ellis Horwood, Chichester. Frank R 1997. Zur Dynamik der Natzung von Baumhöhlen durch ihre Erbauer und Folgenutzer am Beispiel des Philosophenwaldes in Gießen an der Lahn. Vogel und Umwelt, Zeitschrift für Vogelkunde und Naturschutz in Hessen 9: 59-84 Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Gaisler J, Zukal J, Rehak Z & Homolka M 1998. Habitat preference and flight activity of bats in a city. J. Zool,. Lond., 244: 439-445. Gallagher L & Cahill D 1995. Wood Decay and Protection in the Nineties In: Pilcher J & Mac an tSaoir S (eds.) 1995. WOOD, TREES AND FORESTS IN IRELAND. Royal Irish Academy, Dublin. Gibbons D, Reid J & Chapman R 1993. The New Atlas of Breeding Birds in Britain and Ireland: 1988-1991. Poyser, London. Gilbertson R 1980. Wood-rotting fungi of North America. Mycologica 72: 1-49 Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Gilpin Rev. W 1791. Remarks on Forest Scenery and Other Woodland Views. Reprinted 1834. Smith, Elder & Co., London. Glue D 1970. Avian predator pellet analysis and the mammalogist. Mammal Review 1: 53-62. Glue D & Hammond G 1974. Feeding ecology of the Long-eared Owl in Britain and Ireland. Brit. Birds 67: 361-369. Glover A & Altringham J 2008. Cave selection and use by swarming bat species. Biological Conservation, 141: 1493-1504. Goldsmith F 1992. Coppicing – a conservation panacea? In: Buckley G (ed.) 1992. Ecology and Management of Coppice Woodlands. Chapman & Hall, London. Golovko A 1986. Specialization of the group of false tinder fungi. Doklady Akademii Nauk BSSR 30(3): 270-272 Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Gorman G 2004. Woodpeckers of Europe – A Study of the European Picidae. Bruce Coleman, UK. Green T 2010. The importance of open-grown trees: from acorn to ancient. British Wildlife Vol 21, Number 5, June 2010. Greenaway F 2001. The Barbastelle in Britain. British Wildlife. Haensel J 1973. Über die Saisonwanderungen der Wasserfledermäuse, Myotis daubentonii (Leisl.), ausgehend vom Massenwinterquartier Rüdersdorf. – Zool. Abh. Mus. Tierk. Dresden 32: 249–255. Hagvar S, Hagvar G & Moness E 1990. Nest site selection in Norwegian woodpeckers. Holarctic Ecol. 13: 156-165. Hanson C 1934. Forestry for Woodmen; 3rd Edition. Oxford University Press, Oxford. Harding P & Sutton S 1985. Woodlice in Britain and Ireland: Distribution and Habitat. Institute of Terrestrial Ecology, Natural Environment Research Council, Huntingdon. Harmer R, Kerr G & Thompson R 2010. Managing native broadleaved woodland. TSO, London. Harper J 1982. After description. In: Newman E (Ed.) The Plant Community as a Working Mechanism. British Ecological society Special Publications 1: 11-26 Cited in: Rackham O 2006. Woodlands. Collins New Naturalist Series; HarperCollins, London. Harris E & Harris J 1991. Wildlife Conservation in Managed Woodlands and Forests. Basil Blackwell, Oxford. __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Harris S & Yalden D (eds.) 2008. Mammals of the British Isles: Handbook 4th Edition. The Mammal society, London. Hartig R 1891. Lehrbuch der Anatomie und Physiologie der Pflanzen unter besonderer Berücksichtigung der Forstwächse. 1st Ed. Springer, Berlin. Heise G 1985. Zu Vorkommen, Phänologie, Ökologie und Ulsetsstruktur des Abendseglers (Nyctalus noctula) in der Umgebung von Prenzlau/Uckermark. Nyctalus 2: 133-146 Cited in: Dietz C, Helversen O & Dietmar N 2011. Bats of Britain, Europe & Northwest Africa. A & C Black, London. Heise G & Schmidt A 1988. Beiträge zur sozialen Organisation und Ökologie des Braunen Langohrs. Nyctalus (N.F.) 5: 445-465 Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for Woodland Management for Bats. English Nature research reports No. 661, Natural England Peterborough. Helmer W. 1983: Boombewonende Watervleermuizen Myotis daubentonii (Kuhl, 1817) in het rijk van nijmegen. Lutra 26: 1–11. Hewson C, Fuller R, Mayle B & Smith K 2004. Possible impacts of grey squirrels on birds and other wildlife. British wildlife 15: 183-191. Hibberd B (Ed.) 1991. Forestry Commission Handbook 6: Forestry Practice. HMSO, London. Helversen O & Dietmar N 2011. Bats of Britain, Europe & Northwest Africa. A & C Black, London. Hohti P, Celuch M, Danko S & Kanuch P 2011. Constraints in roost-site selection by treedwelling Bechsein’s bat (Myotis bechsteinii). Hystrix It. U. Mamm 22(1): 149-157. Hopkin S 2003. The Woodlouse Name Trail: a Key to Common Woodlice. Field Studies Council. Howe C 1997. An account of three tree roosts in Motherwell. Scottish Bats 4: 9-11. Howes C 1979. The noctule bat, Nyctalus noctula (Schr.) in Yorkshire. Naturalist 104: 31-38. Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Hutterer R, Ivanova T, Meyer-Cords C & Rodrigues L 2005. Bat Migrations in Europe: A Review of Banding Data and Literature. Federal Agency for Nature Conservation, Bonn. Huttunen S & Heikkila H 2001. Trends in European forest tree physiology research. Springer. Imms A 1947. Insect Natural History. Collins New Naturalist Series, Collins, London. James N 1982. The forester’s companion: 3rd ed. Basil Blackwell Ltd, Oxford. Jenkins E, Laine T, Morgan S, Cole K & Speakman J 1998. Roost Selection in the pipistrelle bat, Pipistrellus pipistrelles (Chiroptera: Vespertilionidae), in northeast Scotland. Animal Behaviour 56: 909-917. Jones G & Barratt E 1999. Vespertilio pipistrellus, Schreber, 1774, V. pygmaeus, Leach, 1825, (Currently Pipistrellus pipistrellus and P. pygmaeus; Mammalia, Chiroptera): proposed designation of neotypes. Bulletin of Zoological Nomenclature, 56, 182-186. Kanuch P 2005. Roosting and population ecology of three synoptic tree-dwelling bat species (Myotis nattereri, M. daubentonii and Nyctalus noctula). Biologia 60(5): 579-587. Kerr G & Evans J 1993. Forestry Commission Handbook 9: Growing broadleaves for timber. HMSO, London. Kerth C & Melber M 2009. Species-specific barrier effects of a motorway on the habitat use of two threatened forest-living bat species. Biological Conservation 142: 270-279. Kozlowski T 1971. Growth and Development of Trees: Vol. I, Seed Germination, and Shoot Growth. Academic Press, New York. Cited in: Thomas P 2000. Trees: Their Natural History. Cambridge University Press, Cambridge. __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Kronwitter F 1988. Population structure, habitat use and activity patterns of the noctule bat, Nyctalus noctula Schreb., 1774 (Chiroptera: Vespertilionidae) revealed by radio-tracking. Myotis 26: 23-85. Krzanowski A 1973. Numerical comparison of Vespertilionidae and Rhinolophidae (Chiroptera, Mammalia) in owl pellets. Acta Zoologica Cracoviensia 18: 249-264 Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Lane A & Tait J 1990. The Open University - Practical Conservation: Woodlands. Hodder & Stoughton Ltd, Kent. Leitl R 1995. Nistaskenbewohnende Fledermäuse in einem Waldgebiet der Mittleren Oberpfalz. Diploma thesis, University of Munich. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for Woodland Management for Bats. English Nature research reports No. 661, Natural England Peterborough. Lewis S 1995. Roost fidelity of bats: a review. Journal of Mammalogy 76: 481-496. Lonsdale D 1999. Research for Amenity Trees No.7: Principles of Tree Hazard Assessment and Management. Forestry Commission, London: TSO. Lonsdale D 2000. Hazards from Trees - A general guide. Forestry Commission, Edinburgh. Love R et al. 2000. Changes in the food of British barn owls (Tyto alba) between 1974 and 1997. Mammal Review 30: 107-129 Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Mackie I 2002. Aspects of the conservation biology of the noctule bat. PhD thesis. University of Aberdeen. Cited in: Mackie I & Racey P undated. A literature review of the use of forests by bats to provide information for guidelines for the management of forests for bats. Report to the Bat Conservation Trust, London. Mackie I & Racey P 2007. Habitat use varies with reproductive state in noctule bats (Nyctalus noctula): Implications for conservation. Biological Conservation 140: 70-77. Mackie I & Racey P undated. A literature review of the use of forests by bats to provide information for guidelines for the management of forests for bats. Report to the Bat Conservation Trust, London. Mason C 1972. Noctules and starlings competing for roost holes Journal of Zoology 166: 467. Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Mason C & Stebbings R 1972. Noctules (Nyctalus noctula) and starling (Sturnus vulgaris) competing for roost holes J. Zool. Lond. 166: 467. Matheny N & Clark J 1994. A photographic Guide to the Evaluation of Hazard Trees in Urban Areas. International Society of Arboriculture, Champaign, IL. Mattheck C & Breloer H 1994. The body language of trees – A handbook for failure analyisis. Research for Amenity Trees No. 4. The Stationary Office. Mattheck M & Breloer H 1995. The Body Language of Trees: A handbook for failure analysis (Research for Amenity Trees 4). HMSO, London. Mattheck C & Breloer H 2010. The body language of trees: A handbook for failure analysis. Research for Amenity Trees No. 4. The Stationary Office. McCracken A 1995. The Role of Saprophytic and Pathogenic Woodland Fungi In: Pilcher J & Mac an tSaoir S (eds.) 1995. Wood, trees and forests in Ireland. 1 – 12. Royal Irish Academy, Dublin. McDonald R & Harris S 1998. Stoats & weasels. The Mammal Society, London. Meschede A & Heller K 2000. Ökologie und Schutz von Fledermäusen in Wäldern. Münster: Landwirtschaftsverlag. Schriftenreihe für Landschaftspflege und Naturschutz 66. Cited __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Mickleburgh S 1987. Distribution and status of bats in the London area. In: Hanák V, Horáček I & Gaisler J (eds.) 1989. EUROPEAN BAT RESEARCH 1987. Charles Univ. Press, Praha. Milner E 2011. TREES of BRITAIN and IRELAND. Natural History Museum, London. Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Mitchell-Jones A 2004. Bat Mitigation Guidelines. English Nature, Peterborough. Morris M & Perring F (Eds.) 1974. The British Oak: Its History and Natural History. The Botanical society of the British Isles, E. W.Classey Ltd, Berks. Mortimer G 2005. Foraging, roosting and survival of Natterer’s bats Myotis nattereri, in a commercial coniferous plantation. PhD thesis, University of St Andrews. Murphy S, Greenaway F & Hill D 2012. Patterns of habitat use by female brown long-eared bats presage negative impacts of woodland conservation management. Journal of Zoology. doi:10.1111/j.1469-7998.2012.00936.x. Nagel A & Häussler U 2003. Wasserfledermaus Myotis daubentonii (Kuhl, 1817). In: Braun M & Dieterlen F (eds.). Die Säugetiere Baden-Württembergs, Band 1: Allgemeiner Teil, Fledermäuse (Chiroptera) 440-462. Stuttgart: Verlag Eugen Ulmer. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland management for bats. English Nature Research Report 661, Peterborough. Natural England 2012. Further research on the barbastelle bat, Holnicote National Trust Estate, Exmoor, North Somerset. Natural England Research Reports – Unpublished. Greena Ecological Consultancy, Somerset. Nisbet J 1900. Our Forests and Woodlands. J. M. Dent & Co, London. Nyholm E 1965. The ecology of Myotis mystacinus (Leisl.) and Myotis daubentonii. Annales Zoologici Fennici 2: 77-123 Cited in: Harris S & Yalden D (eds.) 2008. Mammals of the British Isles: Handbook, 4th Edition. The Mammal Society, London. Park K, Altringham J & Jones G 1996. Assortative roosting in the two phoniic types of Pipistrellus pipistrellus during the mating season. Proc. R. Soc. Lond., 263: 1495-1499. Parsons K, Jones G, Davidson-Watts I & Greenaway F 2003. Swarming of bats at underground sites in Britain – implications for conservation. Biological Conservation 111: 63-70. Perks M, Smith S & McEvoy C 2005. Forestry Commission Information Note: Development of Multiple Leaders in Sitka Spruce and Japanese Larch Following Outplanting. Forestry Commission, Edinburgh www.forestry.gov.org. Perrins C 1979. British Tits. Collins New Naturalist Series, Collins, London. Philips J 2008. Thoughts about protection wood, cracks and pruning. California Tree Failure Report Program. http://www.northcoasttreecare.com/H4-ProtectionWood.html. Racey P & Swift S 1985. Feeding ecology of Pipistrellus pipistrellus (Chiroptera: Vespertilionidae) during pregnancy and lactation. I. Foraging behaviour. Journal of Animal Ecology 54: 205-215. Racey P, Swift S, Rydell J & Brodie L 1998. Bats and insects over two Scottish rivers with contrasting nitrate status. Animal conservation 1: 195-202. Rackham O 1976. Trees and Woodland in the British Landscape. Archeology in the Field Series – J. M. Dent & Sons Ltd, London. Rackham O 1995. Looking for Ancient Woodland in Ireland In: Pilcher J & Mac an tSaoir S (eds.) 1995. Wood, trees and forests in Ireland. 1 – 12. Royal Irish Academy, Dublin. __________________________________________________________________________________________ A1 & B1

BAT TREE HABITAT KEY

Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Rackham O 2003. Ancient woodland: its history, vegetation and uses in England: New Edition. Castlepoint Press, Kirkudbrightshire. Rackham O 2006. Woodlands. Collins New Naturalist Series; HarperCollins, London. Ramsbottom J 1953. Mushrooms & Toadstools. Collins New Naturalist Series, Collins, London. Read H 2000. IN13 – Veteran Trees: A guide to good management. Natural England, Peterborough. Rieger I 1996. Tagesquartiere von Wasserfledermäausen, Myotis daubentonii (Kuhl, 1819), in hohlen Bäumen. Schwizer Zeitschrift für Forstwesen 147: 1-20 Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Robson B 2008. Personal communication cited by Shiel C in: Leisler’s bat Nyctalus leisleri Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Ruczyński I & Bogdanowicz W 2005. Roost cavity selection by Nyctalus noctula and N. leisleri (Vespertilionidae, Chiroptera) in Bialowieza primeval forest, Eastern Poland. Journal of Mammalogy 86(5): 921-930. Ruprecht A 1979. Bats (Chiroptera) as constituents of the food of barn owls Tyto alba in Poland. Ibis 121: 489-494 Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Ruprecht A 1990. Bats (Chiroptera) in the food of the owls in the Nadnotecka Forest. Przegląd Zoologiczny 34: 349-358 Cited in: Harris S & Yalden D 2008. MAMMALS OF THE BRITISH ISLES: HANDBOOK, 4TH EDITION. The Mammal Society, London. Schofield H & Fitzsimmons P 2004. The importance of woodlands for bats. In: Managing Woodlands and their Mammals: proceedings of a Joint Mammal Society/Forestry Commission symposium. Forestry Commission, Edinburgh. Schmidt A 1988. Beobachtungen zur Lebensweise des Abendseglers, Nyctalus noctula (Schreber 1774), im Süden des Bezirks Frankfurt/O. Nyctalus 2: 389-422. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Schober W & Grimmberger E 1987. Bats of Britain and Europe. Hamlyn Guide, Hamlyn Publishing Group Limited. Schober W & Grimmberger E 1997. The Bats of Europe & North America. T.F.H. Publications, Inc. U.S.A. Schofield H & Mitchell-Jones A 2003. The Bats of Britain and Ireland. The Vincent Wildlife Trust, Herefordshire. Schorcht W et al. 2002. Zur Ressourcennutzung von Rauhhautfledermausen (Pipistrellus nathusii) in Mecklenburg. In: MESCHEDE, A., HELLER, K.-G. & BOYE, P. eds. Okolgie, Wanderungen und Genetik von Fledermausen in Waldern, 191-212. Untersuchengen als Grundlage fur den Fledermausschutz Munster: Landwirtschaftsverlag. Schriftenreihe fur Landschaftspflege und Naturschutz 71, p. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Schwarze F & Fink S 1998. Hose and cell type affect the mode of degradation by Meripilus giganteus. New Phytol 139: 721-731 Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. __________________________________________________________________________________________ A1 & B1

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Sedgeley J & O’Donnell C 1999. Factors Influencing the Selection of Roost Cavities by a Temperate Rainforest Bat (Vespertilionidae: Chalinolobus tuberculatus) in New Zealand. J. Zool (London) 249: 437-446. Sharrock J 1976. The Atlas of Breeding Birds in Britain and Ireland. Poyser, Berkhamstead. Shaw M 1984. Insects associated with birch. Proceedings of the Royal Society of Edinburgh 85: 169-181 Cited in: Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Shiel C, Shiel R & Fairley J 1999. Seasonal changes in the foraging behaviour of Leisler’s bats (Nyctalus leisleri) in Ireland as revealed by radio-telemetry. J. Zool. Lond., 249(3): 347-358. Shigo A & Marx H 1977. Compartmentalization of decay in trees. USDA Forest Service, Agriculture Information Bull. 405, 73. Shigo A 1979. Tree Decay, An Expanded Concept. USDA Forest Service, Agriculture Information Bull. 419. Shigo A 1986. A New Tree Biology Dictionary. Shigo and Trees, Associates. USA ISBN 0943563-12-7. Shigo A 2000. A New Tree Biology comes of age. Tree Care Industry magazine, September 2000. Shigo A 2008. Modern Arboriculture: A systems approach to the care of trees and their associates. Shigo and Trees Associates, USA. Shorten M 1954. Squirrels. Collins New Naturalist Series Special Volume, Collins; London. Siemers B & Swift S 2006. Differences in sensory ecology contribute to resource partitioning in the bats Myotis bechsteinii and Myotis nattereri (Chiroptera: Vespertilionidae). Behav Ecol Sociobiol 59: 373-380. Simms E 1971. Woodland birds. Collins New naturalist Series no. 52. Collins, London. Simms E 1979. Woodland Birds. Collins New Naturalist Series, Collins, London. Smith K 1987. The ecology of the great spotted woodpecker. RSPB Conservation Review 1: 74-77 Cited in: Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Smith K 1997. Nest site selection of the Great Spotted Woodpecker Dendrocopus major in two oak woods in Southern England and its implications for woodland management. Biological Conservation, 80, 283-288. Smith P 2001. Habitat preference, range use and roosting ecology of Natterer’s bats (Myotis nattereri), in a grassland-woodland landscape. PhD thesis, University of Aberdeen. Pp 297. Cited in: Mackie I & Racey P Undated. A literature review of the use of forests by bats to provide information for guidelines for the management of forests by bats. Report to the Bat Conservation Trust. Smith P & Racey P 2002. Habitat Management for Natterer's Bat, Myotis nattereri. London : Mammals Trust UK. Smith P & Racey P 2005. The itinerant Natterer: physical and thermal characteristics of summer roosts of Myotis nattereri (Mammalia: Chiroptera). J. Zool. Lond., 266: 171180. Sparks J & Soper T 1970. Owls – Their natural and unnatural history. David & Charles, Newton Abbot. __________________________________________________________________________________________ A1 & B1

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Sections A & B. TREES & TREE-ROOSTING BATS References __________________________________________________________________________________________

Speakman J 1991. The impact of predation by birds on bat population in the British Isles. Mammal Review 21(3): 123-142. Spizenberger F 2001. Die Säugetierfauna Österreichs. Grüne Reihe 13, Vienna: Bundesministerium für Land und Forstwirtschaft, Umwelt und Wasserwirtschaft. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for Woodland Management for Bats. English Nature research reports No. 661, Natural England Peterborough. Spooner B & Roberts P 2005. Fungi. Collins New Naturalist Series, HarperCollins, London. Stebbings R 1998. Conservation of European Bats. Christopher Helm, London. Stebbings R, Mansfield H & Fasham M 2005. Bats In: Hill D, Fasham M, Tucker G, Shewry M & Shaw P (eds) 2005. Handbook of Biodiversity Methods. Cambridge University Press. Steele R 1975. Forests and wildlife. Philosophical Transactions of the Royal Society 271: 163-178 Cited in: Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Stenberg I 1996. Nest site selection in six woodpecker species. Fauna Norvegica, Series C, 19, 21-38. Step E (1921) Animal Life of the British Isles: A Pocket Guide to the Mammals, Reptiles and Batrachians of Wayside and Woodland. Frederick Warne & Co. Ltd., London. Step E (Ed.) 1924. Trees & Flowers of the Country-side. Hutchinson, London. Step E 1946. Animal Life of the British Isles – A guide to the Mammals, Reptiles and Batrachians of Wayside and Woodland. 11th Impression. Frederick Warne & Co. Ltd, London. Sterling P & Hambler C 1988. Coppicing for conservation: do hazel communities benefit? Research and survey in nature conservation 15: 69-80 Peterborough, Nature Conservancy Council. Cited in: Mitchell P & Kirby K 1989. Ecological Effects of Forestry Practices in Long-established Woodland and their Implications for Nature Conservation, Oxford Forestry Institute Occasional Paper, 39, Department of Plant Sciences, University of Oxford. Stone H 1921. A textbook of wood. Rider & Son Ltd. Stratmann B 1978. Faunistisch-ökologische Beobachtungen an einer Population von Nyctalus noctula im Revier Ecktannen des StFB Warn (Müritz). Nyctalus 1: 2-22 Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Strelkov P 1983. Myotis mystacinus and M. brandtii in the USSR and interrelation of these species Part 2. Zoological Journal 62: 259-271 Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Strubbe D & Matthysen E 2007. Invasive Ring-necked Parakeets Psittacula krameri in Belgium: habitat selection and impact on native birds. Ecography 30: 578-588. Sutton S 1980. Woodlice. A Wheaton & Co. Ltd, Exeter. Swift S 1997. Roosting and foraging behaviour of Natterer’s bats (Myotis nattereri Kuhl 1818) close to the northern border of their distribution. J. Zool. Lond., 242: 375-384. Swift S 1998. Long-eared bats. London: Poyser. Taake K 1984. Strukturelle Untersciede zwichen den Sommerhabitaten von Kliener und Großer Bartfledermaus (Myotis mystacinus und M. brandti) in Westfalen. Nyctalus 2: __________________________________________________________________________________________ A1 & B1

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16=32 Cited in: Harris S & Yalden D (eds.) 2008. Mammals of the British Isles: Handbook, 4th Edition. The Mammal Society, London. Thomas P 2000. Trees: Their Natural History. Cambridge University Press, Cambridge. Thomson A & Rankin G 1923. Britain’s Birds & their Nests. W & R Chambers Ltd, Edinburgh. Thompson D 1995. Biological problems and potential solutions in tree breeding In: Pilcher J & Mac an tSaoir S (eds.) 1995. Wood, trees and forests in Ireland. 1 – 12. Royal Irish Academy, Dublin. Thompson M 1992. Roost philopatry in female pipistrelle bats Pipistrellus pipistrellus. J. Zool. Lond., 228: 673-679. Cited in: Hutterer R, Ivanova T, Meyer-Cords C & Rodrigues L 2005. Bat Migrations in Europe: A Review of Banding Data and Literature. Federal Agency for Nature Conservation, Bonn. Tudge C 2006. The secret life of trees: How they live and why they matter. Penguin Books Ltd, London. Verboom B & Huitema H 1997. The importance of linear landscape elements for the pipistrelle Pipistrellus pipistrellus and the serotine bat Eptesicus serotinus. Landscape Ecology 12(2): 117-125. Verboom B & Spoelstra K 1999. Effects of food abundance and wind on the use of tree lines by an insectivorous bat, Pipistrellus pipistrellus. Canadian Journal of Zoology, 77(9): 1393-1401 Cited in: Russ J, Briffa M, Montgomery W 2003. Seasonal patterns in activity and habitat use by bats (Pipistrellus spp. and Nyctalus leisleri) in Northern Ireland, determined using a driven transect. J. Zool. Lond., 259: 289-299 Vesey-Fitzgerald B 1949. British Bats. Methuen & Co Ltd, London. Vierhaus H 2004. Pipistrellus nathusii (Keyserling und Blasius, 1839) – Rauhhautfledermaus. In: KRAPP F (ed.). Handbuch der Säugetiere Europas, Band 4: Fledertiere, Teil II: Chiroptera II. 825-873. Wiebelsheim: Aula-Verlag. Cited in: Boye P & Dietz M 2005. Development of good practice guidelines for woodland managements for bats. English Nature Research Reports 661, Peterborough. Village A 1981. The diet and breeding of Long-eared Owls in relation to vole numbers. Bird Study 28: 215-224. Vonhof M & Barklay R 1996. Roost-site selection and roosting ecology of forest-dwelling bats in southern British Columbia. Canadian Journal of Ecology 74: 1797-1805. Walsh A, Catto C, Hutson A, Racey P, Richardson P, and Langton S 2001. The UK’s National Bat Monitoring Programme Final Report. Department for Environment, Food and Rural Affairs. Warren R, Waters D, Altringham J & Bullock D 2000. The distribution of Daubenton’s bats (Myotis daubentonii) and pipistrelle bats (Pipistrellus pipistrellus) (Vespertilionidae) in relation to small-scale variation in riverine habitat. Biological Conservation 92: 85-91. Waters D, Jones G & furlong M 1999. Foraging ecology of Leisler’s bat (Nyctalus leisleri) at two sites in southern Britain. J. Zool. Lond., 249: 173-180. Watling R 1982. Taxonomic status and ecological identity in the basidiomycetes. In: Frankland J, Hedger J & Swift M (eds.) Decomposers basidiomycetes: their biology and ecology. Cambridge University Press, Cambridge. Cited in: Schwarze W, Engels J & Mattheck C 2000. Fungal Strategies of Wood Decay in Trees. Springer. Watson R 2006. Trees: Their Use, Management, Cultivation and Biology. The Crowood Press Ltd, Marlborough. Weber K & Mattheck C 2003. Manual of Wood Decays in Trees. Arboricultural Association, Gloucestershire. White G (1789) The Natural History of Selborne. Cassell & Company, London. __________________________________________________________________________________________ A1 & B1

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