White Admiral Newsletter 84
Spring 2013
Suffolk Naturalists’ Society
Contents Editorial
Be n Heather
1
Chala ra - As h D iebac k
Steve Sc ott
2-3
Su ffol k Ba t Group Up date a nd l ooking Sue Hooton forwa rd
4-6
New ton & Wrigley
S teve Piotrowski
Bee tl in g a bout on Orford Beach
Chris Hitc h
Rec ording Purp le Hairs trea ks al ong Weste rfield R oad
R ic hard S tewa rt
1 0-1 1
A Sh ort Up date on Suffol k D orm ice
Liz Cu tting
12-14
Stag Bee tle Pre dators
Bob Ste bbings
15-16
T wo in teres ting records from the Grove Farm m on itoring project
Adrian Cha lkley
1 6-1 9
T he impac t of s tree t l igh ting on plants
Ad rian Kn owles
2 0-2 1
Alde r Gall/Fungus
Colin Ja cobs
Where is Th orpe Ness?
Ca rol ine Ma rkham
AGM & Spring Mem bers Evening
7 8-9
21 22-23 24-25
R oseh il l sale n otice
25
Ge o Suffol k F iel d Meetin g
26
Halesw orth Festival of Ec ol ogy
27
Eve nts by Su ffol k Bu tte rfly Conserva tion
28
ISSN 0959-8537 Published by the Suffolk Naturalists’ Society c/o Ipswich Museum, High Street, Ipswich, Suffolk IP1 3QH Registered Charity No. 206084
Cover photograph of Brimstone taken by Matt Berry at Holywells Park, Ipswich http://www.greenwings.co/
Newsletter 84 - Spring 2013 Even if the weather isn’t showing it, there are a few signs that spring may indeed be on its way. I am writing this editorial on another day disrupted by snow (12th March) and remembering that only a week ago we were experiencing temperatures that, in some places, exceeded 15°C. With that heat came the first messages, through the Suffolk Natural History Yahoo group, of Brimstone butterflies on the wing, in West Stow and Sudbury. A species I always associate with the changing seasons, I thought Matt Berry’s excellent capture on the front cover may spread some hope that winter will soon end. As I continue my editorship of the White Admiral I would like to thank all who have contributed to what is a very full issue, but please keep sending copy in, this is your newsletter! Please also turn your attention to the back pages of this edition where you will find details of the SNS AGM and some interesting events that will be running this Spring/Summer. One of these events is the SNS, SOG and SWT Taster Day, on 29th June, at Knettishall Heath. This promises to be a chance to sample and see what we do and is open to all, expert or novice. More details to follow… For snippets and other news please visit our website www.sns.org.uk or follow @SuffolkBRC on twitter.
Edit o r : B e n He a t he r Suffolk Biological Records Centre, c / o I p s w i c h M u s e u m , H i g h S t r e e t , I p s w ic h , I P 1 3 Q H b e n . h e a t h e r @ s u f f o l k . go v . u k White Admiral 84
1
Chalara ash dieback
Don’t panic! Scientists think that this disease has been with us for three or four years, but I couldn’t point you to a single mature tree that has died. There really is no need to act in haste, but be aware and be prepared.
Chalara fraxinea is a fungus that spreads from ash leaves into the tree and blocks the water-carrying vessels, thus starving the tree of water and minerals. Young trees and fresh growth may die quickly, but older trees can survive for years. First 2
observed
in
Poland,
the
disease has spread through Europe since the early 1990s, and was finally discovered in the wild on the east coast of Britain in October 2012. Although we might expect to see a spread across the whole country over the years, the initial hot spots appear to be in Suffolk, Norfolk and Kent. The Forestry Commission is working with Natural England on guidelines on the ecological aspects of Chalara, but in the meantime as a professional forester, I would suggest the following basic dos and don’ts: White Admiral 84
Don’t plant ash, certainly not until the disease has run its course and/or resistant strains are developed.
Do use this as an excuse to plan t oth er tr ees. Th e woodland cover of England is 10% compared to the European average of over 40%. There are many sensible alternative native species with which to replace ash (pick the right tree for the right place), and if native is not a key factor, there are some close visual replacements such as walnut and hickory.
Don’t coppice or pollard.
Don’t fell mature ash trees just because you suspect disease or because an unscrupulous tree surgeon tells you so. Obviously, h ealth and safety is paramount, but employ a fully qualified member of the Arboricultural Association or follow the guidance in “A common sense approach to tree safety” (www.ntsg.org.uk).
Do consider burning, burying or composting ash leaves in gardens or tree collections to limit the spread of C. fraxinea spores.
Do continue to manage woodland. There are many options so contact your local
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Forestry Commission Woodland Officer.
Do keep access to woodland open. The risk of woodland visitors spreading the disease is low, but take sensible precautions – for example, brush leaves and twigs off boots, clothing and other items taken into the woodland, and wash boots and bicycle wheels etc… when returning home from a walk. Avoid routes which go from wood to wood to wood. If organising a parish walk, for example, it might be sensible to provide washing facilities (some bowls or trugs and stiff brushes at the end).
It’s worth pointing out that there are many new diseases and pests of trees that have hits these shores in the last few years, some as serious as Chalara, but less infamous. It is important to keep an eye on the health of all trees. For the latest information keep an eye on www.forestry.gov.uk/ chalara. Specifically you might like to look at the three videos we shot late last year, two on identifying the symptoms and one on biosecurity. Steve Scott Forestry Commission 3
Suffolk Bat Group update and looking forward Suffolk Bat Group was formed in 1984 as a specialist group within the Suffolk Wildlife Trust and is the county’s main point of contact for all bat conservation related issues. It is one of 90 bat groups nationwide and co-operates with The Bat Conservation Trust and Natural England. The aim is to assist in the protection of bats in Suffolk through advising householders, landowners, builders and developers. Over the years much effort has been put into protecting, enhancing and creating hibernation sites, carrying out surveys using bat detectors and computer software, establishing bat box projects and carrying out specific surveys on barns and churches. Over 2200 records have been collected on 13
Ba t Survey in g Š Arthu r Rive tt 4
species, of which two new species have been discovered and one rediscovered after many years absence in the county. Suffolk Bat Group was very busy in 2012 and one highlight was producing a new distribution atlas for bats in Suffolk, in conjunction with SBRC. This updated the atlas, from 2000, shows the spread of different bat species throughout the county. The new atlas not only shows, due to an increase recording activity and improvements in bat detecting technology, a rise in the number of bat records collected, since the last atlas in 2000, but also an increase in the number of different species being recorded. The new atlas can be downloaded from the SBRC website (www.suffolkbrc.org.uk/) and the Suffolk Bat Group pages on Suffolk Wildlife Trust website White Admiral 84
(www. su ffolkw ildlifetru st.org/ s p ec ie s- an d-h a bi t a ts / s pec i es projects/suffolk-bat-group/) . Suffolk Bat Group sends all records to SBRC from a variety of sources that help to update the atlas including;
Bat roost visits for Natural England
Monitoring of bat hibernation sites
Bat detector surveys
National Bat Monitoring Project (NBMP) surveys
Bat walks / events
Suffolk Bat Group bat detector surveys are carried out at various fixed points around a site, specifically identified as suitable habitat for bats. The points are chosen because they offer good sheltered feeding areas for bats so as to maximize the amount of feeding activity detected. Batbox Duet bat detectors are used in conjunction with digital recorders to record bat echolocation and recording times are synchronized, running for 90 minutes. Analysis of the recordings is done later on computer using Batscan and Batsound analysis programmes. No experience is necessary to take
D i s t r i b u t i o n m a p f or B a r b a s t el l e b a t f r om S u f f ol k B a t A t l a s 2 0 1 1 White Admiral 84
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Th e NBM P survey s ar e organised by Bat Conservation Trust through a volunteer network to monitor the status of many of our bat species across a range of habitats. Anyone can take part in these surveys and some are aimed at beginners as well as experts. BCT provides on -line tutorials to help identify the species encountered (www.bats.org.uk) and there are a whole series of surveys that you can get involved in. Regular counts of breeding colonies do not require any bat licence and are easy to carry out. Slightly more involved are the Field, Waterways and Nathusius’ pipistrelle surveys; these involve walking a set route of 1Km twice per annum with a bat detector and counting the number and species of bats encountered whilst walking and/or at fixed point locations. Surveys at hibernation sites require a licensed batworker so are aimed at trained individuals.
Ba rbastelle ba t Š Arthu r R ivett
part in these surveys and repor ts ar e pr ov ided to landowners on managing their woodland for bats.
detector and are willing to volunteer for a survey, please get in touch. We are hoping to get funding for lots of bat detectors to loan out to members for NBMP surveys so if you’re interested in taking part, do let us know as this will help our funding applications. All records will help to fill in the gaps in the bat atlas maps so if you fancy coming getting involved in bat surveys, you can join in the fun!
Sue Hooton Chairperson Suffolk Bat Group info@suffolkwildlifetrust.org 01473 890089
To further promote the NBMP surveys, Suffolk Bat Group is planning more training workshops for 2013 so if you know of a bat roost near you or have a bat 6
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Photo by: Jon Evans
Newton and Wrigley
Soap fans would recognise Newton and Ridley as the fictional brewery portrayed in Coronation Street, famously serving its ales in the Rovers Return. As a slight deviation from this title, a rather enterprising black-headed gull (christened Newton) has been watched devouring literally hundreds of smooth newts (Wriggly) in a small, shallow pond, which has been formed at the site of a former car park at RSPB Minsmere Nature Reserve in Suffolk. This extraordinary behaviour was originally logged by Reserve Warden, Robin Harvey and then later by Paul Green, Jon Gibbs, Jon Evans, myself and many others. The gull was seen to make regular forays to a small pond where it would catch and eat White Admiral 84
newts almost at will. It employed two hunting techniques; either swimming through thin phragmites reed margins, stirring up sediments in shallow water with its feet and then duckdiving to retrieve its prey or, by hovering over the water surface and then plunge diving at the sight of a newt. The gull was fearless in pursuit of its prey, ignoring bystanders and becoming completely submerged. Black-headed gulls are undoubtedly opportune feeders and, although Birds of the Western Palearctic states that amphibian tadpoles and adults are “rarely taken”, it makes no specific mention of newts forming any part of the black-headed gull’s diet. By late summer, “Newton” was looking rather smug, albeit a little plump, however, as winter approached and the newts were no longer in the pond, he ceased his patrols. It will be interesting to see if he returns again in spring to exploit his newly discovered food source. Steve Piotrowski
7
Beetling about on Orford Beach In May and August of last year, two bioblitz recording sessions were organised to look at Orford Ness and the finger of stable shingle running down the coast between the river and the sea, ending at North Weir Point, more or less opposite Shingle Street. On one of the days, July 5th 2012, a boat was made available to take some of the party down the river to be dropped off at various points along the spit. My brief was to study the lichens and the first stop was at Orford Beach, OS Grid Reference TM 426480 (Landranger series, sheet 169). While there, a large patch of Cladonia rangiformis, about 1 metr e squ ar e, w as n oted. Surrounding the patch of lichen and half buried in tallish grass or sedge, was what appeared to be a fairly recently killed rabbit carcass, due to its gory nature. The accompanying picture shows some invertebrate larvae feeding on the remains. None of the larvae were collected, but the picture shows them clearly and this was circulated to various experts in the hope of getting a d e t e r m i n a t i on . T h e y w e r e 8
immediately recognised as carrion beetle larvae of the subclass Silphidae, in the genus Silpha and thought to be either Silpha atrata or S. tristis, but without specimens it was not sure which. It was then decided to send the picture further afield, to a colleague in Yorkshire and his remarks are included: “They are
indeed Silphidae larvae, almost certainly Silpha tristis. The larvae of Silpha obscura are shorter and more rounded, whilst the larvae of Silpha atrata, from what I can gather, lack the yellow spots on the outer edges of the tergites. Silpha obscura is a rare beast, but the other two species are common and generally distributed.� The adult S. tristis beetle is black and about 15mm long and pictures of it can be seen on the Web, under Sipha, as can its distribution, on a general map of the British Isles. There are more spots around the coast, with dense colonisation around The Wash and the Ouse estuary. However, quite a few records are inland and it appears to be almost virtually restricted to England, as far north as Cumbria, with a single record in Scotland and none in Ireland. It is known
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from Suffolk, with 1 record south of Thetford, 12 records to the southwest of the Brecklands, 2 to the east of Ipswich and 1 to the north of Southwold.
So this is for a new record for Orford Ness and the spit to the south. C. J. B. Hitch
Larvae of Silpha tristis. Photo by Chris Hitch White Admiral 84
9
Photo by Gary Last
Recording Purple Hairstreaks al on g We s t e r f ie ld R oad
Anyone travelling at a moderate speed from Westerfield village back into Ipswich should be aware of the abundance of oak trees along the lane. Several were included as ‘veterans’ in a parish tree survey I conducted a few years ago. The Purple Hairstreak flies mainly in July and early August, is about the size of a Small Copper, and its life cycle is dependent on oaks. We first discovered it one evening at Westerfield railway station, around nearby oaks and ash. This was a sunlit evening and this time of day is usually best to observe them, dancing ‘like a handful of 10
silver coins that had been tossed into the sunlight’, to quote butterfly expert Jeremy Thomas. Despite close scrutiny the oaks back from the station to Valley Road yielded no further sightings, until the evening of 12th July 2005. Conditions were ideal, with continuous sunlight and virtually no breeze. Our normal twelve minute walk back home was considerably lengthened as we counted the butterflies around eighteen separate oaks. We also solved the mystery regarding single Purple Hairstreaks recorded in our garden during the two White Admiral 84
previous years. That evening we counted four around a large Oak on the corner of Borrowdale Avenue, only a few yards from our home. More were seen in a tall Sycamore just beyond our back garden. Obviously our garden sightings were of this species passing between these two trees. Oak, Ash and Sycamore are normally the most bountiful in honeydew, the Purple Hairstreak’s main food. Ironically we had recently dug out a vegetable and fruit plot under this spreading and tall Sycamore and seen the produce affected by the fallen honeydew, a liquid secreted by aphids. We have now recorded garden Purple Hairstreaks from 2003 to 2012, with just one blank in 2007. Nectaring has only been observed once, on a tall Buddleia davidii in 2009. Although 2012 was a poor butterfly year, I recorded the species on a garden Ash just fifty
yards further on from the Borrowdale Avenue Oak. That still left a considerable gap along Westerfield Road until the many oaks in adjacent Christchurch Park. Here we had looked, straining our necks, unsuccessfully. However, on 15th July 2012 three were recorded on an Oak at the north end of the park, early afternoon. Further observations were rewarded on 12th August, again early afternoon, when a single specimen was seen flying high on an Oak, appropriately just a few yards from the newly created butterfly garden. These two park sightings were about two hundred yards apart. I am now convinced the Purple Hairstreak is present in many of the park’s oaks and I will make it a target species for the park in 2013.
Richard Stewart, SNS Member
Contributions to White Admiral Deadlines for copy are 1st February (spring edition), 1st June (summer edition) and 1st October (autumn edition).
The opinions expressed in White Admiral are not necessarily those of the Editor or of the Suffolk Naturalists’ Society.
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A Short Update on Suffolk Dormice A lot has happened in the last ten years or so. Suffolk had two licensed dormouse handlers in the first years of this century. Now we have more than a dozen, and the number is growing. This has allowed us to increase the number of sites that are monitored as part of the National Dormouse Monitoring Programme (NDM P). Usu ally these sites have a minimum of 50 dormouse nest boxes each (our biggest site has 250) and we typically survey these three times a year. As a T o r p i d D o r m o u s e - L i z C u t t i n g protected species, surveyors have to be licensed by Natural pg.7-9). The remainder of the England, and the Suffolk & Essex Suffolk sites are ‘natural’, Dormouse Group is active in although DNA analysis of the training surveyors to enable them Bonny Wood population is aiming to obtain a licence and then to to establish to what extent this is participate in the large survey a natural population, or whether effort involved. it has been colonised from the nearby release site in Priestley The sites include large and small Wood. In terms on ongoing woodlands and hedgerows, and all monitoring, it makes no difference are west of Ipswich. Suffolk has of course. two ‘release’ sites (Bradfield Woods and Priestley Wood) where captive bred dormice have been r eleased u n der c on tr olled conditions (see White Admiral 79 12
From our monitoring, we know that numbers fluctuate a fair bit, and it is best not to rush to conclusions. The more you learn, White Admiral 84
the more you realise that, despite dormice being one of the better surveyed UK mammals, we actually still have huge gaps in our knowledge. On the face of it, 2012 has been quite a poor year for dormice, with most Suffolk sites recording significantly lower numbers than 2011. The attached chart shows the dormouse numbers per 50 boxes at the autumn surveys for our three largest sites. The most likely factor was probably the abysmal spring/ summer. Our dormice will have spent more time than usual in torpor, have probably had difficulty fin din g g ood food sour c es
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(especially early in the year), and had reduced breeding success. Anecdotal evidence around the country however is quite mixed; many surveyors reported similar reductions and low numbers, but there were also reports of good dormouse numbers at other sites, sometimes close to sites with downturns. Hopefully, Peoples Trust for Endangered Species (PTES) will be able to throw some light on the underlying situation once they have all the data collected and analysed. Through a lot of hard work, particularly by Alison Looser, we continue to find new dormouse sites in Suffolk, usually in or near
13
Su rveying- Al ison Looser
almost certainly dormice there in 2004, perhaps in small numbers, or perhaps in areas of the wood not surveyed.
parishes with existing known sites, so dormouse populations appear to some extent in clusters. In 2012, seven sites have been added – in the parishes of Layham, Polstead, Assington, Felsham and Tattingstone. In 2011, we added Wolves wood, the RSPB reserve near Hadleigh, to the list of dormouse populations. Interestingly, a survey in 2004 at the wood, failed to show any evidence of dormice. However you can’t prove a negative and we felt the only negative aspect of the wood was that it was very wet (the habitat structure and food availability were ideal for dormice). A repeat survey in 2011 however revealed a number of dormouse nests. As the wood is quite isolated and bearing in mind the fact that dormice really only travel through trees and shrubs (not on the ground) there were
14
Suffolk Naturalists’ Society and the Essex & Suffolk Dormouse Group agreed to fund the purchase of 60 dormouse nest boxes and these were put out in March 2012. Of all the sites we survey, Wolves wood is one of the most demanding, as the coppiced areas (likely to be favoured by dormice) are populated with very dense hawthorn and dog rose as well as thick herbaceous vegetation, mainly in plots fenced to exclude deer. This may be good for dormice, but it is really hard work for the survey team (see photo). In what has generally been a rather disappointing dormouse year in Suffolk, we found only a single dormouse nest at our October check. This winter, we will be cleaning out nest boxes at all our sites and at Wolves wood, with its thick bramble clumps, we are also going to spend a little time looking for natural dormouse nests. Liz Cutting Essex & Suffolk Dormouse Group White Admiral 84
Stag Beetle Predators -
Letter in response to
Vol. 83 - Colin Hawes’ article on pp 5 -6 Colin Hawes’ revealing article r ec oun ting th e pr edatory behaviour of a starling and noting a list of known consumers of this beetle in Britain and Europe, is remarkable for the obvious omission of the prime specialist insectivores, Chiroptera - bats. One third of our native mammal species are bats and they are almost exclusive consumers of insects. Most insects are caught by bats in the air but some species of bat catch prey on foliage, tree trunks or on the ground. In the early 1960s I worked in Dorset and on warm summer evenings I tried to locate a colony of serotine bats ( Eptesicus serotinus) which fed over a grassy open space, Whitecliff Harbourside Park, bordering Parkstone Bay, Poole (NGR: SZ 031907), now a local Nature Reserve. The essential element of this procedure is to be on site early at dusk waiting for the first sightings of bats to see the direction they come from. On successive nights one takes up a new position along the line the bats have taken and hopefully, eventually after a few nights’ observations the roost location is identified.
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At first, the bats were feeding mostly on cockchafers (Melolontha melolontha) but by later June were concentrating on the smaller summer chafer ( Rhizotrogus solstitialis). These beetles have a body mass of approximately 1g and 0.5g respectively. The serotines in mid-summer average 22g. The northern boundary of the grassland rises steeply into an ancient bank of a hawthorn hedge with many oak trees immediately to the south of Whitecliff Road. The latter have grown considerably in the last 50 years and are now dominant on that bank. The soil type is Bagshot sands, known to be suitable for Stag beetles. On the warmest evenings some very large insects emerged from the bank and flew ponderously southwards over the mown grass and immediately the serotines chased and attacked from above. The beetles were male stags. The bats behaved in two ways. Sometimes they caught the beetle in the air and flew back to and landed on the trees and shrubs to eat their quarry but others knocked the beetle to the ground where the bat landed to kill and eat their prey. The chafers were 15
usually caught in the air and then the bat would go into a circling flight pattern eating the beetle with crunching sounds being clearly heard and wings and legs raining to the ground. Only the largest bats with substantial canine teeth are large enough to tackle these huge beetles which have a body mass averaging a bit over 2g (figures kindly provided by Colin Hawes). The serotine lives in East Anglia and often feeds close to or even by catching prey on the ground. In south west Britain, the greater horseshoe bat ( Rhinolophus ferrumequinum) feeds in a similar way often behaving like a flycatcher, grabbing a chafer and returning to a favourite perch. However, there is no knowledge it catches stag beetles. The noctule ( Nyctalus noctula), which is
widespread in East Anglia, tends to fly high and fast and does feed on chafers but I do not know of any records of it eating stag beetles. On mainland Europe, the greater mouse-eared (Myotis myotis) is known to feed close to the ground, often landing to catch prey. It is reported that this bat smells beetles as it flies low overhead but also, with its large ears, it will hear the noises of insects crawling out of holes and warming their flight muscles before takeoff. Serotines often catch prey on the ground and may also hear and smell potential prey. In limited parts of Suffolk where the stag beetle is known to be fairly plentiful, it would be worth making observations at dusk to see if serotines or other bats preyed on them. Bob Stebbings
Two Interesting records from the Grove Farm Monitoring Project In the Autumn issue of White Admiral, no. 83, Juliet Hawkins and Rob Parker outlined the monitoring project at SWT’s Grove Farm Reserve. This is being undertaken by a team of U3A volunteers with funding provided by an SNS Bursary. For aquatic invertebrates alone the project so far has amassed 345 records from 16
17 of the 20 ponds at the reserve. Recording continues during 2013 and in due course analysis of the results will begin to tell us how the new ponds are being colonised, providing a more detailed picture of mid-Suffolk fauna. However, I feel that two of the new species recorded are worth a separate note here. White Admiral 84
Wautie r’ s lim pe t Barn Meadow Pond is one of the existing farm ponds at the reserve, which was restored in 2008. Within the pond Tony Sear & Barney Harrison, two U3A volunteers, found a freshwater snail, a limpet named Ferrissia wautieri (Wautier’s Limpet). One might expect the native Lake Limpet, Acroloxus lacustris, in a pond like this but F. wautieri is in fact an introduced species which has only been recorded from five other widespread sites in Suffolk; at Elveden, Elmsett, Holbrook, Bixley & Lavenham. The species was unknown (or overlooked) in Europe until 1944 and was first recognised in Britain in 1976. There is some debate about how it came into Europe but studies suggest that the North American Ferrissia fragilis is a cryptic invader of European and east Asian freshwater ecosystems (Walther et al. 2006). The most likely introduction method is the aquaria supply trade, the usual suspect for unexpected introductions. The species is known by several names; Ferrissia
rapidly, it has been shown to grow from hatching to egg laying in as little as 11 days. It should be noted, if anyone tries to look for Wautier’s limpet in their own pond, that the maximum size of the animal is only 3 mm. Examining floating leaves and the submerged stems of reeds and grasses is the best way to find it. I suspect that the species was introduced in most, possibly all, of the Suffolk sites by visiting water fowl. Coincidentally, the duck leech Theromyzon tessulatum, an internal parasite of water fowl, has also been recorded at almost all of the five sites mentioned above.
fragilis, F, clessiniana & F. wautieri, the latter being the most commonly used in Europe. Once established and in good conditions the population can build up White Admiral 84
17
No tod roma s mon ac ha, a n O st ra cod Ostracods are small crustacean arthropods which are housed within a bivalve carapace similar to a very small mussel. Pond dipping children are often encouraged to call them ‘Baked Bean Creatures’, a term which may infuriate serious naturalists, but does describe the animal very well. Very few Ostracods have been recorded to species level in the county but at Millers Middle Pond, Grove Farm an interesting Ostracod, Notodromas monacha was collected by Lawrence Child from the U3A group. The record for N. monacha is as far as I know only the second for Suffolk, being first recorded by Ceri Hopkins, the then Assistant Director of Flatford Mill, from Meadow Dyke, Flatford in 1961. The photograph from above shows the two halves of its shell (the valves) and you can see the hinge between the valves and the paired eye spots. The other is taken from the side showing the limbs protruding from between the valves. It uses the limbs for swimming and for collecting its food, microscopic algae. It is a species typical of nutrient rich still 18
waters and is probably widespread across the county and vastly under recorded. The photo shows the limbs projecting upwards because, uniquely amongst British Ostracods, N. monacha swims upside down just under the surface film whilst collecting its food. N. monacha is darkly coloured on its ventral side (which is next to the surface film) and this is thought to be an adaptation to living in increased UV light and / or perhaps as camouflage against predation from above. The same surface film niche is exploited by a few very small aquatic invertebrates. N. monacha itself is at most 1mm long, the accompanying photos being taken through a microscope. The interesting thing about this record is that Millers Middle Pond is a new pond dug in September White Admiral 84
2010. It filled a little during the winter of 2010 but no Ostracods were recorded there in 2011. N. monacha has appeared during 2012, but has not been recorded from any of the o th er ponds on the farm. It is quite possible it was also introduced by birds but then again Ostracods can produce resting stages (diapausing eggs) which may have been carried by the wind from a nearby pond during a dry spell, remembering the drought in early 2012! A search for the same species elsewhere on the farm will be undertaken this coming year, but cannot really prove things either way. However it dispersed into this new pond it bred rapidly, Lawrence described hundreds, maybe thousands of them across the water surface. But then Ostracods, like many crustaceans are able to reproduce asexually to boost a population and exploit ideal conditions. I would be very interested in getting reports of any similar sightings from elsewhere in Suffolk in the future. Adrian Chalkley
References: Walther, A. C., Lee, T., Burch, J. B. and Foighil, D. Ă“. 2006. Confirmation that the North American ancylid Ferrissia fragilis (Tryon, 1863) is a cryptic invader of European and East Asian freshwater ecosystems. Journal of Molluscan Studies 72(3): 318321 Henderson, P. A. 1990. Freshwater Ostracods. Synopses of the British Fauna (New Series) No. 42 Linnean Society, London
A ll image s b y Ad ria n C ha lkle y
Aquatic Invertebrate recorder White Admiral 84
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The impact of street lighting on plants It is not uncommon to hear songbirds such as Blackbird, Robin and Song Thrush singing well into a summers night in urban areas, where extensive street lighting dupes the birds into thinking it is still only dusk. However, the effect this lighting has on plants is usually a bit less obvious. All the same, the photo here shows that there is occasionally a discernible impact. For the last
two years, this Birch tree in Capel St Mary has retained a patch of green leaves below a street light well beyond the time when the rest of the leaves have been shed. The lamp is surrounded by the lower twigs on one side of the tree. The photo was taken after a period of strong winds, showing that the leaves were not only green, but still firmly attached to the twigs and probably functioning as if they were fresh foliage. This phenomenon has been known about for some time, however. As long ago as 1936, Edwin Matzke wrote in the American Journal of Botany (Volume 23, no. 6. June 1936) with observations of several species of tree in New York City (read his paper at http:// www.jstor.org/stable/2436035). Matzke noted that even quite low levels of light could result in a few green leaves being retained on nearby twigs in Poplars (Populus spp.), Planes (Platanus spp.) and Crack Willow (Salix fragilis). Interestingly though, in the spring bud burst was not advanced by the presence of this lighting, compared to unlit parts of the same tree.
Ph oto by Ad ria n K n owles 20
Further information on this phenomenon can be gained at the web site White Admiral 84
http://physics.fau.edu/observatory/ lightpol-Plants.html, which points out some of the negative impacts this can have on trees. In extreme cases, where large parts of the tree retain leaves late into the winter, the increased weight of trapped snow and ice can cause bough collapse damage. Green leaves still hold essential plant nutrients that would normally be withdrawn into the tree before the leaves are shed. If these green leaves are damaged or killed by frosts, because they have not fallen in autumn, this can lead to a long-term significant
nutrient loss for trees, especially those suffering from other environmental stresses. The ability to photosynthesise late into the night and later in the year is not necessarily a good thing. As part of this process, plants actually need a period of more-or-less complete darkness, so the tendency to bathe our front gardens in low levels of street lighting may be having more of an effect than one might first think. Adrian Knowles
Alder Gall / Fungus Lowestoft TM59 In July 2012 I was checking for plant galls on planted Italian Alders (Alnus cordata) along the Kirkley Stream/Spine Road in South Lowestoft (Kirkley). I found my first Suffolk Alder Gall/Fungus Taphrina alni also known as Alder tongue. The reddish orange tongue was only growing on female Cones and numbered less than 20. There are (as yet) no records of T. alni in the British Mycological Society database but I expect there are some unpublished records somewhere. There are a handful of records from Norfolk typically from Ted Ellis. The Common Alder (A. glutinosa) was unaffected by these galls but the leaves were covered in another fungal gall Taphrina tosquinetii at nearby Kirkley Fen. Colin Jacobs White Admiral 84
Photo by Col in Jac obs 21
Where is Thorpe Ness?
Suffolk’s coastline is characterised by its ‘nesses’ – large triangular sand/shingle beaches extending out from the coast. There are five in all: Orford Ness (superimposed on the shingle spit), Thorpe Ness, Benacre Ness, Lowestoft Ness and (in Norfolk) Winterton Ness. The dominant wind on our coast is from the north, so net movement of beach material is to the south. Thus there is accretion of material on the north-facing beaches of the ‘nesses’ and loss of material from the south side, thus the ‘ness’ itself moves northwards over an extended period of time. (Perhaps Winterton Ness was once in Suffolk?). In the case of Benacre Ness, this northward movement is well-documented by V.J. May in the Geological Conservation Review. 6km in 200 years means that it has changed its name from Covehithe Ness to Benacre Ness and indeed should today be called Kessingland Ness, (Pakefield next?). The ‘nesses’ are an integral part of the sediment cycle of the Suffolk coast and, apart from Lowestoft 22
Ness, they are undefended, allowing natural processes to operate. Orford Ness and Benacre Ness have protection as SSSIs and, in September 2012, GeoSuffolk designated Thorpe Ness a County Geodiversity Site (CGS). GeoSuffolk had visited and recorded the site in 2008 (for a description of this beautiful stretch of coast see our handbook, Earth Heritage Suffolk). However, to create a CGS designation a site boundary must be mapped onto the Suffolk Biological Records Centre GIS database to supplement the site record. Thus, on July 14th 2012 GeoSuffolk, helped by Open University Geological Society members, checked the location of Thorpe Ness. The field party walked to the Ness at low tide and each individual stood at the point on the shoreline they thought was furthest from the cliff. They formed a spread of about 50 metres along the shore and a GPS reading was taken at the ‘central’ person - 52˚11.331’N, 1˚37.398’E. It was also noted that the ‘central’ person was standing
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opposite and about 50 metres north of the point where the boundary marking the northern edge of Thorpeness Common intersects the cliff. The latitude and longitude data were given to Ben Heather at SBRC to plot on a large scale map, kindly reproduced here (with the boundary of the CGS subsequently drawn by GeoSuffolk). Not only does this concur with the visual record made on the field trip, it also coincides with the ‘Thorpe Ness’ label on the 1998 OS map, so there has been no discernable movement in the last 14 years.
which extends under the sea at this point. Abraded pieces of crag from the submarine outcrop are commonly found on the beach here. Could it be that its position astride this relatively hard rock formation has stabilised the ness, restricting its movement northwards?
Thorpe Ness lies at the north-east end of the Coralline Crag outcrop
Markham,C.J., 2010. Thorpe Ness. Earth Heritage Suffolk. GeoSuffolk
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Caroline Markham, GeoSuffolk References: May,V.J., 2003. Benacre Ness, Suffolk. Coastal Geomorphology of Great Britain. GCR Series.
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8 4 th A N N U A L G E N E R A L M E E T I N G a n d S p r i n g Members Evening 7.30 p.m. Thursday 11th April 2013 Cedars Hotel, Needham Road, Stowmarket, IP14 2AJ AGENDA
1. Apologies for absence 2. Minutes of the 83rd Annual General Meeting 3. Chairman’s and Treasurer’s Report – Joan Hardingham 4. Secretary’s Report – Gen Broad 5. Election of members to the Council: Tony Prichard to be co-opted back onto Council - proposed by Martin Sanford, seconded by Joan Hardingham. Ann Ainsworth to be co-opted back onto Council - proposed by Roger Dixon and seconded by Martin Sanford Colin Hawes to be co-opted as an ordinary member proposed by David Walker and seconded by Gen Broad. David Walker to be co-opted as an ordinary member from April - proposed by Martin Sanford and seconded by Adrian Chalkley. There are vacant positions for a Programme Secretary and two Ordinary Members of Council. 6. Rosehill 7. Any Other Business (The Chairman reserves the right to consider only items submitted in writing 2 weeks before the AGM.) Refreshments Tea and coffee will be served at the close of formal business. Following the conclusion of formal business and refreshments:
Presentations by Diane Ling, of Suffolk FWAG “Suffolk Native crayfish survey” and Colin Lucas “Suffolk Leafhopper survey 2012”, both projects funded by SNS.
Other member presentations are welcome.
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The Society’s publications will be on sale during the evening. Directions The Cedars Hotel is situated on the B1113 between Stowmarket and Needham Market. From the A14, turn off towards Stowmarket on the A1120 and then turn right onto the dual carriageway. The Cedars Hotel is on the right hand side, clearly signposted. A map is available on The Cedars Hotel website: http://www.cedarshotel.co.uk/map.html
Notice in connection with the sale of R o s e h i l l Wo o d The Charity Commission has agreed that SNS may sell Rosehill Wood. This land was given to the Society under the will of Mrs Frances Elizabeth Rivis. It forms a charity is known as Trust property held in connection with Suffolk Naturalists’ Society (charity no. 206084-1). This has been agreed by the Trustees of SNS and notified to members at previous AGMs. The sale is subject to a new Scheme being drawn up. As the land is defined as designated land, SNS Trustees must, before entering into an agreement for a contract for the disposal, give this notice to their members under section 121 of the Charities Act 2011. The site is an area of about 14 acres of mixed woodland once attached to Rosehill house on the A1094 at Farnham, Suffolk IP17 1JU. It would be sold freehold, through a land agent. Representations need to be made within one calendar month of the next SNS AGM on April 11th 2013. Any such representations should be sent to the Chairman of the Suffolk Naturalists’ society, c/o The Museum, High St. Ipswich IP1 3QH.
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Field meeting: The geology of Suffolk’s lost city – Dunwich
N orw ic h Cr ag s a n ds & ov erl y in g g ra v els
St . James ’ Churc h – ove r 20 di ff er en t r ock t y pes
S u n d a y J u l y 7 t h, 2 0 1 3 Leaders: Roger Dixon and Bob Markham Dunwich and its history will be familiar to many of you. However, the processes and materials that have shaped that history may not be so well known. This field excursion will examine the coastal marine processes that have led to the rapid retreat of the cliffs (1 ½ miles in the last 2,000 years) and the unconsolidated sands and gravels of which they are made, the Norwich Crag and Westleton Beds. In an area that is not noted for its local building stones, Dunwich village is, however, of great interest and serves to illustrate not only changing styles of architecture and materials, but also changes in industry, agriculture and commerce, and social and political history. The leper chapel, for example, illustrates Norman decorative stone-work and St. James’ church contains a surprising variety of ‘foreign’ stone. The boundary wall of Greyfriars contains Coralline Crag, currently being restored using Crag from Sudbourne, and other local stone is in evidence. Optional extra: after lunch (beach café, pub or bring packed lunch) we will visit a nearby former gravel pit to examine the Westleton Beds in more detail. The present is the key to the past – how do geologists interpret the environment of deposition? Meet at the public beach car park (TM 479707) at 10.00hrs. Our geo-walk will take about 3 hours, and will include walking along 1km of beach shingle. A leaflet on the geology of Dunwich can be downloaded (free) from the GeoSuffolk web-site: www.geosuffolk.co.uk 26
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Halesworth Halesworth Millennium Green Trust have been awarded funding from the British Ecological Society to carry out an extensive program of ecological research, surveying and training on the Green. This is part of the nationwide series of events the BES has planned for their ‘Festival of Ecology’ centenary celebrations in 2013. The program of events is currently at the embryonic stage but as of present the following is planned:
‘ Go W ild on Wed ne sda y’ e ve ning work shops & Sunda y d a ytime workshops Wed 19th June
6.30 - 9pm
Geology/Ecology
Wed 26th June
6.30 - 9pm
Plants
Dale Peck/Richard Wollnough Graham Peck
Sun 30th June
10am - 3pm
Wed 3rd July
6.30 - 9pm
Mammals/Reptiles & Amphibians Hedges & Trees
Kelly Jacobs/ Etienne Swarts Mike Wade
Sun 7th July
10am - 3pm
Graham Peck
Wed 10th July
6.30 - 9pm
Dragonflies & Damselflies Bats
Wed 17th July
6.30 - 9pm
Owls
Alan Miller/ Etienne Swarts
‘ Eco Fa ir’ – to be held on the weekend of the 1 3 th/ 1 4 th J u l y Sat 13th July
Science & Surveying Day
Sun 14th July
Craft & Creative Day
If anyone requires further details or wishes to lend their expertise for a specialist workshop then please contact: Dale Peck on 01502 578343 or email dale.peck7@btinternet.com or Nicky Rowbottom on 01502 578470 or email nicky.rowbottom@btinternet.com http://millenniumgreen.halesworth.net White Admiral 84
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Future events organised by the Suffolk Branch of Butterfly Conservation Visit to Flowton Brook Farm
Spring walk to survey butterflies on John Cousins’ 350 acre farm - 01473 726649
23/04/2013
Spring Butterfly Watching for Novice Recorders Barnham Village Hall/ Barnhamcross Common
An indoor training session, followed by practical butterfly watching on an excellent site. Enrol in advance 01284 705476
04/05/2013
Start of Dingy Skipper Week - Kings Forest
Help with surveys for Dingy Skipper. Please contact Rob Parker in advance to notify availability for other dates 01284 705476
15/05/2013
Coastal Butterflies
Walk around the Covehithe/Benacre/ Kessingland area looking for butterflies and other wildlife. Contact Bill Stone - 07906 888603
26/05/2013
Moth night at Purdis Heath
Lead by Tony Prichard - 01473 270047
08/06/2013
Silver-studded Blue Survey Please register in advance - 01284 at Minsmere RSPB reserve 705476
28/06/2013
Silver-studded Blue Survey Please register in advance - 01284 at RSPB Minsmere (part 2) 705476
05/07/2013
Pakenham Wood for Silver- A chance to look for this recently 14/07/2013 washed Fritillary returned fritillary. Lead by Mike Dean - 07754115368 Butterflies on the Heath
Joint event with SWT at Knettishall Heath reserve. Contact Matt Berry 07599 243026
27/07/2013
Wildlife Garden visit Aldeburgh
An invitation from B.C. member Mrs Trudie Willis, to visit her 10 acre garden, including a Buddleia & Honeysuckle collection
28/07/2013
Visit www.suffolkbutterflies.org.uk for more details and more events 28
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Suffolk Naturalists’ Society Bursaries The Suffolk Naturalists’ Society offers five bursaries, of up to £500 each, annually. Morley Bursary - usually awarded for studies involving insects (or other invertebrates) other than butterflies and moths. Chipperfield Bursary - usually awarded for studies involving butterflies or moths. Cranbrook Bursary - usually awarded for studies involving mammals or birds. Rivis Bursary - usually awarded for studies into the County’s flora. Simpson Bursary - in memory of Francis Simpson; this will be for a botanical study where possible. Any member wishing to apply for a bursary should write, with details of their proposed project, to the Honorary Secretary. As applications are normally considered at the Council meeting in May of each year, proposals should be with the Hon. Sec. by 30th April. Applications made at other times will be considered but, even if considered worthy of an award, may not be successful if all the bursaries for the current year have already been taken. The following two conditions apply to the awards: Projects should include a large element of original work and applications must include a breakdown of how the bursary will be spent. A written account of the project is required within 12 months of receipt of a bursary. This should be in a form suitable for publication in one of the Society’s journals: Suffolk Natural History, Suffolk Birds or White Admiral.
SNS, SO G & SWT Taster Day 29th June 2013 - Knettishall Hea th Aqua tic & te rres trial inve rts, dragonfl ies, moths, fl ora, birds, ge ol ogy & more… More info to come w ww.sns. org.u k
FOUNDED IN 1929 by Claude Morley (1874 -1951), The Suffolk Naturalists’ Society pioneered the study and recording of the County’s flora, fauna and geology, to promote a wider interest in natural history. Recording the natural history of Suffolk is still one of the Society’s primary objects, and members’ observations are fed to a network of specialist recorders for possible publication before being deposited in the Suffolk Biological Records Centre, which is based in Ipswich Museum.
Suffolk Natural History, a review of the County’s wildlife, and Suffolk Birds, the County bird report, are two high quality annual publications issued free to members. The Society also publishes a newsletter, White Admiral, and organises two members’ evenings a year plus a conference every two years .
Subscriptions: Individual members £15.00; Family membership £17.00; Corporate membership £17.00. Joint membership with the Suffolk Ornithologists’ Group: Individual members £28.00; Family membership £32.00. As defined by the Constitution of this Society its objects shall be: 2.1 To study and record the fauna, flora and geology of the County 2.2 To publish a Transactions and Proceedings and a Bird Report. These shall be free to members except those whose annual subscriptions are in arrears 2.3 To liaise with other natural history societies and conservation bodies in the County 2.4 To promote interest in natural history and the activities of the Society. For more details about the Suffolk Naturalists’ Society contact:
Hon. Secretary, Suffolk Naturalists’ Society, c/o Ipswich Museum, High Street, IPSWICH, IP1 3QH. Telephone 01473 433547
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