Water vole mapping project

National Water Vole Database and Mapping Project Guide to the Use of Project Outputs to End of 2011

Catherine McGuire, Deborah Whitfield and Helen Perkins Published: 2013

Water Vole Database and Mapping Project

This document provides a brief introduction to the National Water Vole Database and Mapping Project, outlines the methodology used to produce the database and maps and provides guidance on how to use and interpret the mapping produced to date. We would welcome feedback and comments on the outputs produced by the project to date. Section 5 suggests how this work could be developed in the future, but we would value additional suggestions from data suppliers and others.

Contents 1. Project introduction

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2. Project methodology

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2.1

Data collation and formatting

2.2

Data supply agreements

3. Project outputs 3.1 Extent of dataset 3.2 Mapping

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4. Alert and key areas mapping overview

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5. Concluding remarks and recommendations

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6. References

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Appendix 1 Water vole and American mink distribution maps

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Appendix 2 Water vole alert and key areas maps

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Figures Figure 1 Standardised spreadsheet used to collate datasets Tables Table 1 Total number of records in national database Table 2 Suppliers of water vole data for England, Scotland, Wales Table 3 UK Water vole distribution maps: quick guide Table 4 UK American mink distribution maps: quick guide Table 5 Water vole alert maps: quick guide Table 6 Water vole local key area maps: quick guide Table 7 Water vole regional key area maps: quick guide

Cover photograph by Tom Marshall

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1. Project introduction The revised national Biodiversity Action Plan (BAP) targets for water vole, published in 2006 were as follows: T1 Maintain the current range (730 occupied 10km squares) of water vole in UK. T2 Achieve an increase in range by 50 new occupied 10km squares in the UK by 2010.

Achieve a further increase in range by 55 new occupied 10km squares by 2015; 60 new occupied 10km squares by 2020 and 55 new occupied 10km squares by 2030.

In 2007 the UK Water Vole Steering Group highlighted the need for a concerted effort to collate and map available data in order to assess the national status and trend of the species and to report against national BAP targets. It also recognised the potential of a water vole GIS to support conservation measures and enable more strategic working at local, regional and national levels. The Water Vole Database and Mapping Project was established in January 2008 with funding provided by the Environment Agency, Royal Society of Wildlife Trusts (RSWT) and People’s Trust for Endangered Species. The project is managed by RSWT, with work delivered by a Water Vole Information Officer based at Hampshire Wildlife Trust.

The specific aims of the project are to: 

Develop standardised methods for storing and managing water vole (Arvicola amphibius) and American mink (Neovison vison) data

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Collate existing water vole and American mink data

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Develop a GIS to enable mapping of data and to maximise the use of the datasets

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Establish procedures for enabling annual updates to the dataset

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Disseminate key outputs from the project to UK and LBAP partners

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Ensure sustained and effective use of datasets and methodologies developed during the life of the project.

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2. Project development 2.1 Data collation and formatting In 2008, the project requested water vole and American mink data for all years from Local Record Centres, Wildlife Trusts and other data suppliers. Data suppliers were asked to provide data in an Excel spreadsheet. As expected, the column headings and format of the data were variable. A new spreadsheet with a limited number of headings, as shown below, was established and used to collate the relevant data provided.

Figure 1: Standardised spreadsheet used to collate datasets Since then, data suppliers have been asked to provide a data update on an annual basis.

This project outputs guide is based on data held prior to and including 2011. This was collated from suppliers in 2012, enabling time for suppliers to process and input 2011 survey data.

As agreed by the UK Water Vole Steering Group, the Project’s mapping for assessment of status and trends covers the last five years. For this report therefore, the mapping provided in Appendix 1 covers 2007-2011 inclusive.

2.2 Data supply agreements Data supply agreements were completed and exchanged between the project and data suppliers; between the project and the Environment Agency and between the project and Scottish Natural Heritage.

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3. Project outputs 3.1 Extent of dataset Table 1 shows the number of records held in the database. Data for the current update was received from 82 different data suppliers across England, Scotland and Wales. These are listed in Table 2.

Table 1: Total number of records in national database by year 2009

2010

2011

Water vole presence

36,898

42,006

50,717

Water vole absence

10,288

10,463

11,734

American Mink presence

7,883

8,582

9,146

American Mink absence

4,213

4,213

5,136

Otter presence

-

1,874

-

Some of the datasets initially collated by the Project were extensive and included water vole records dating back to the early 1900s. The majority of data however were from the mid 1990s to the present day. The earliest water vole record was dated 1900 and the earliest American mink record was 1952.

3.2 Mapping Mapping produced by the Project comprises national distribution maps (Appendix 1) and alert and key areas maps (Appendix 2). The maps were produced by importing the data into the MapInfo GIS. It is essential to note that there are limitations with the data set and with the methodologies used to produce the mapping and that care is needed in interpreting the maps. Tables 3-7 list all the maps and highlight some words of caution. Section 3.2.1 below provides some detail regarding production of the alert and key areas maps.

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Table 2: Suppliers of water vole data for England, Scotland and Wales 2008 onwards Suppliers of water vole and American mink data 2008-2012 ENGLAND Bedfordshire & Luton Biodiversity Recording and Monitoring Centre Berkshire, Buckinghamshire & Oxfordshire Wildlife Trust Bristol Regional Environmental Records Centre Cheshire Mammal Group Cornwall Wildlife Trust Cumbria Biodiversity Data Centre Cumbria Wildlife Trust Derbyshire Wildlife Trust Devon Biodiversity Records Centre Devon Water Vole Recovery Project, East Devon District Council Dorset Environmental Records Centre Dorset Wildlife Trust Durham Wildlife Trust EcoRecord: Birmingham & The Black Country Environment Agency Environmental Records Centre for Cornwall and the Isles of Scilly Environmental Records Information Centre North East Essex Wildlife Trust Gloucestershire Centre For Environmental Records Greater Manchester Ecology Unit Greenspace Information for Greater London H.M.P. Full Sutton Hampshire & Isle of Wight Wildlife Trust Herefordshire Biological Records Centre Hertfordshire & Middlesex Wildlife Trust Kent & Medway Biological Records Centre Lancashire Natural Environment Record Network Lancashire Wildlife Trust Leicestershire & Rutland Wildlife Trust Leicestershire Environmental Resources Centre Lincolnshire Environmental Records Centre Lincolnshire Wildlife Trust Merseyside BioBank Norfolk Biodiversity Information Service Norfolk Wildlife Trust Northamptonshire Biodiversity Records Centre Northumberland Wildlife Trust Northwest Lowlands Water Vole Project Nottinghamshire Mammal Group Nottinghamshire Wildlife Trust Operation Otter: Devon

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Water Vole Database and Mapping Project Paul Gambling (Local Recorder) River Axe Water Vole Recovery Project Royal Holloway: University of London Sheffield Biological Record Centre Sheffield City Council: City Ecology Unit Shropshire Wildlife Trust Somerset Environmental Records Centre Staffordshire Mammal Group Staffordshire Wildlife Trust Suffolk Biological Records Centre Suffolk Wildlife Trust Surrey Biological Records Centre Surrey Wildlife Trust Sussex Biodiversity Record Centre Sussex Wildlife Trust Tees Valley Wildlife Trust The Wildlife Trust for Bedfordshire, Cambridgeshire, Northamptonshire & Peterborough Warwickshire Wildlife Trust Wiltshire and Swindon Biological Records Centre Wiltshire Wildlife Trust Worcestershire Biological Records Centre Yorkshire Wildlife Trust SCOTLAND Alan Ross Cairngorms Water Vole Conservation Project Dumfries & Galloway Environmental Record Centre Forestry Commission Scotland Glasgow Museums Biological Records Centre Highland Biological Recording Group International Otter Survival Fund John Muir Trust Lothian Wildlife Information Centre Perth Museum & Art Gallery Scottish Borders Biological Record Centre Scottish Natural Heritage The McManus: Dundee's Art Gallery and Museum The National Trust for Scotland University of Aberdeen: Institute of Biological and Environmental Sciences WALES Countryside Council for Wales Environment Agency Wales The Wildlife Trust of South and West Wales West Wales Biodiversity Information Centre

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4. Alert and key areas mapping overview Using water vole data from the last five years, the aim of the alert and key areas maps is to identify the areas known to support water vole populations and suggest where some of the more robust populations may be found. This mapping work aims to complement the outputs of the National Key Sites Project, which developed from a study by Bright and Carter (2000).

The methodology for producing the alert and key areas mapping is based on work undertaken originally by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust, which is summarised in the second edition of the Water Vole Conservation Handbook (Strachan, R. and Moorhouse, T., 2006). Mapping is produced by buffering water vole records to capture some of the potential surrounding habitat and areas within average water vole dispersal distance. A figure of 0.5km (measured from occupied watercourses) has been used to capture some of the surrounding habitat and a figure of 2km, as measured from water vole records, has been used to capture dispersal distance. It is suggested that this 2km buffer should capture dispersal areas on most occasions, though water voles have been recorded as dispersing over longer distances. Telfer et al (2003) recorded the average dispersal distance in an upland area to be 2.18 +/- 0.27 SE km for females and 1.65 +/- 0.27 SE km for males. This study found dispersal distance of animals in lowland areas to be 1.04 +/- 0.19 SE km for females and 1.50 +/- 0.25 SE km for males. In a study in the Peak District, Johnson (2008) recorded the maximum distance from an occupied transect to a core colony as 1.3km, with single latrines recorded at 1.9km.

To date three tiers of mapping have been produced (alert, local and regional key area maps) for each of the English government regions, for Wales and for Scotland. A further map has been produced to display the Regional Key Areas across the UK. Printed versions of these maps are available in Appendix 2.

The methodology used to derive the Alert Maps can be summarised as follows:       

All positive records from the last five years of the project dataset are selected and entered onto a single formatted spreadsheet in Excel.

The records are filtered to remove all records of 1km resolution, giving a data set comprising records at or greater than 100m resolution.

The water vole alert area is made up of a collection of 0.5km buffer zones, generated from the water vole data by using the MapInfo GIS. Many of these buffer zones are around river sections which have been identified as lying within 1.5km of a water vole record.

The remaining buffer zones are generated around water vole records which lie outside the river sections identified above.

The river section buffer zones include an additional 0.5km length at either end, thus buffering a total of 2km from the nearest water vole record.

All records and selected river sections lying within 2km of each other are grouped.

These groups are applied to the buffer zones and used to identify the key areas.

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Using the alert layer, Local Key Areas are identified by selecting areas of 6km2 and over.

Rob Strachan (pers.comm.) has suggested that selecting alert areas of 6km2 and over could help identify those areas that are important for maintaining the sustainability of the local water vole population. These Local Key Areas are likely to support one of the following: o several colonies of water voles occupying an area of a river system or waterway o robust populations at large but isolated non linear sites o a series of sub populations that form a metapopulation covering an extensive upland area.

Using the alert layer, Regional Key Areas are identified by selecting areas of 35km2 and over. Rob Strachan (pers.comm.) has suggested areas of 35km2 and over could help identify those areas where water vole populations are more likely to survive the impacts of stochastic events and more likely to persist for more than 40 years.

Tables 3-7 below provide a quick guide to using and interpreting both the national distribution maps for water vole and mink and the alert, local and key areas maps. It is important to stress that the mapping is intended as a tool to assist water vole conservation in the future and that identification of local and regional key areas using the methodology described above does not confer any statutory or non-statutory designation.

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Table 3 UK Water vole distribution maps: quick guide UK Water Vole Distribution Maps Map title

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Resolution

UK- Water vole presence all records (1900-2011)

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Derived from records ≥ 100m resolution

UK- Water vole presence all records (1900-2011)

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UK- Water vole presence (2007-2011)

Display format Dots

Uses

Caution

For: -providing overview of distribution across UK since records began -helping to plan further survey/ research at national level.

Derived from records ≥ 1km resolution

10km squares

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Derived from records ≥ 100m resolution

Dots

For: -providing overview of distribution across UK since records began -reporting against UK BAP targets -helping to plan further survey/ research at national level.

For: -providing overview of distribution across UK over the last 5 years -helping to plan further survey/ research at national level.

UK- Water vole presence (2007-2011)

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Derived from records ≥ 1km resolution

10km squares

UK- Water vole absence all records (1900-2011)

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Derived from records 100m Derived from records 100m

Dots

Does not: -purport to capture all areas historically or currently occupied by water voles ( to an extent reflects recorder effort) -indicate abundance -show status over time.

Does not: -purport to capture all areas historically or currently occupied by water voles (to an extent reflects recorder effort) -indicate abundance -show status over time.

Does not: -purport to capture all areas historically or currently occupied by water voles ( to an extent reflects recorder effort) -indicate abundance -show status over time.

Does not: -purport to capture all areas historically or currently occupied by water voles (to an extent reflects recorder effort) -indicate abundance -show status over time.

Does not: -indicate areas where water voles have been absent historically or are currently absent.

UK- Water vole absence (2007-2011)

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≥

For: -providing overview of distribution across UK over the last 5 years -reporting against UK BAP targets -helping to plan further survey/ research at national level.

For: -indicating where absence recorded during survey.

For: - indicating where absence recorded during survey.

Dots

≥ 10

Does not: -indicate areas where water voles have been absent historically or are currently absent.

Water Vole Database and Mapping Project

Table 4 UK American Mink distribution maps: quick guide UK American Mink Distribution Maps Map title

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Resolution

Display format Dots

Uses

Caution

UK-American mink presence all records (19522011)

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Derived from records ≥ 100m

For: -providing overview of distribution across UK since records began -helping to plan further survey / research at national level.

Derived from records ≥ 1km resolution

10km squares

For: -providing overview of distribution across UK since records began -helping to plan further survey / research at national level.

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Derived from records ≥ 100m

Dots

For: -providing overview of distribution across UK over the last five years -helping to plan further survey/ research at national level

UK-American mink presence (2007-2011)

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Derived from records ≥ 1km resolution

10km squares

For: -providing overview of distribution across UK -helping to plan further survey / research at national level

UK-American mink absence (1952-2011)

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Derived from records ≥ 100m

Dots

For: - indicating where absence recorded during survey.

UK-American mink absence (2007-2011)

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Derived from records ≥ 100m

Dots

For: - indicating where absence recorded during survey.

Does not: -separate mink survey records from mink trapping records. Mink ‘presence’ may in some cases represent an animal that has been ‘removed’ from the population.

Does not: -separate mink survey records from mink trapping records. Mink ‘presence’ may in some cases represent an animal that has been ‘removed’ from the population.

Does not: -separate mink survey records from mink trapping records. Mink ‘presence’ may in some cases represent an animal that has been ‘removed’ from the population.

Does not: - separate mink survey records from mink trapping records. Mink ‘presence’ may in some cases represent an animal that has been ‘removed’ from the population.

Does not: - indicate areas where mink have been absent historically or are currently absent.

Does not: - indicate areas where mink have been absent historically or are currently absent

UK-American mink presence all records (19522011)

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UK-American mink presence (2007-2011)

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Table 5 Water vole alert maps: quick guide Water Vole Alert Maps Map title Scotland Water Vole Alert Map

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Wales Water Vole Alert Map

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East Midlands Water Vole Alert Map

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East of England Water Vole Alert Map

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London Water Vole Alert Map

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North East Water Vole Alert Map

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North West Water Vole Alert Map

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South East Water Vole Alert Map

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South West Water Vole Alert Map

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West Midlands Water Vole Alert Map

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Yorkshire & Humberside Water Vole Alert Map

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Data displayed Derived from records ≼ 100m with buffers added.

Uses For: -identifying at least some of the potentially suitable habitat within water vole dispersal distance of populations recorded over the last five years -alerting users to potential presence of water voles -assisting with the collation of data for agri-environment schemes -alerting organisations that undertake regular maintenance tasks to the potential presence of water voles -planning future water vole survey and monitoring.

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Caution These maps do not: -confer any statutory or non-statutory designation -provide a precise boundary defining presence/absence of water voles and/or their habitat e.g. the 0.5 wide buffer along occupied watercourses will not always capture the extent of adjacent suitable habitat.

-identify other potentially suitable habitat into which populations may move in the future -remove the need to consider other mapping/imagery to assess habitat suitability -remove the need to undertake new surveys prior to determining development/engineering/habitat works. Sub populations can disappear from sites and/or re appear from one survey season to the next.

Populations may also move in response to relatively small changes in habitat quality.

Water Vole Database and Mapping Project

Table 6 Water vole local key area maps: quick guide Water Vole Local Key Area Maps Map title Scotland Water Vole Local Key Areas

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Wales Water Vole Local Key Areas

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East Midlands Water Vole Local Key Areas

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East of England Water Vole Local Key Areas

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London Water Vole Local Key Areas

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North East Water Vole Local Key Areas

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North West Water Vole Local Key Areas

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South East Water Vole Local Key Areas

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South West Water Vole Local Key Areas

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West Midlands Water Vole Local Key Areas

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Yorkshire & Humberside Water Vole Local Key Areas

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Data displayed Alert areas over 2 6km derived from records ≼ 100m with buffers added

Uses For: 2 - indicating areas ≼ 6 km that are likely to support larger populations/clusters of populations that have a greater chance of persisting long term -encouraging protection and/or sensitive management of potentially suitable habitat within and adjacent to sites where water voles recorded in the last five years -assisting with designation of local wildlife sites -targeting survey and monitoring efforts -targeting habitat enhancement and creation works -targeting mink control efforts -assisting with the development of agri environment scheme applications

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Caution These maps do not: -confer any statutory or non statutory designation -provide a precise boundary defining presence/absence of water voles and/or their habitat (as outlined in Table 5) -identify other potentially suitable habitat into which populations may move in the future -remove the need to consider other mapping/imagery to assess habitat suitability -remove the need to undertake new surveys prior to determining development/engineering/habitat works. Sub populations can disappear from sites and/or re appear from one survey season to the next. Populations may move in response to small changes in habitat quality.

-show smaller populations, which may decline due to stochastic events.

-highlight small colonies or small clusters, which are highly unlikely to persist without positive intervention. In some areas these small colonies may be essential in aiding recovery of populations and may also regarded as locally important.

Water Vole Database and Mapping Project

Table 7 Water vole regional key area maps: quick guide Water Vole Regional Key Area Maps Map title Scotland Water Vole Regional Key Areas

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Wales Water Vole Regional Key Areas

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East Midlands Water Vole Regional Key Areas

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East of England Water Vole Regional Key Areas

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London Water Vole Regional Key Areas

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North East Water Vole Regional Key Areas

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North West Water Vole Local Regional Areas

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South East Water Vole Regional Key Areas

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South West Water Vole Regional Key Areas

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West Midlands Water Vole Regional Key Areas

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Yorkshire & Key Areas

Humberside Water Vole Regional

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England, Scotland and Wales Regional Key Areas

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Data displayed Alert areas over 2 35km derived from records ≼ 100m with buffers added

Uses For: 2 -indicating areas ≼ 35 km where populations are more likely to survive the impacts of stochastic events and to persist > 40 years.

-prioritising long term strategic policy initiatives -facilitating collaborative working -prioritising resource allocation -targeting mink control efforts at regional level -assisting with designation of statutory and non-statutory sites -targeting survey and monitoring efforts at regional level -targeting habitat works at regional level -encouraging protection and/or sensitive management of potentially suitable habitat within and adjacent to occupied water vole sites -assisting with the development of agri environment scheme applications

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Caution These maps do not: -confer any statutory or non statutory designation -provide a precise boundary defining the presence or absence of water voles and/or their habitat (as outlined in Table 5) -identify other potentially suitable habitat into which populations may move in the future -remove the need to consider other mapping/imagery to assess habitat suitability -remove the need to undertake new surveys prior to determining development/engineering/habitat works -show smaller populations, which may decline due to stochastic events, -highlight small colonies or small clusters, which are highly unlikely to persist without positive intervention. In some areas these small colonies may be essential in aiding recovery of populations. They may represent all or most of the remaining populations in the area and may also be regarded as regionally important.

Water Vole Database and Mapping Project

5. Concluding remarks and recommendations 5.1 Staff and volunteers working for The Wildlife Trusts, Natural England, Scottish Natural Heritage, Countryside Council for Wales, the Environment Agency, Vincent Wildlife Trust, Internal Drainage Boards, Local Authorities and many other organisations have expended considerable effort on commissioning and undertaking surveys for water vole and American mink since the early 1990s. The data generated by this work has been supplemented by data from a number of academic studies. The hard work and diligence of staff and volunteers at Local Record Centres and other organisations has ensured that the data generated by these surveys and studies can be used to further conservation of the species. Thanks to the co operation and enthusiasm of staff at the organisations holding water vole and mink data, we have been able to create and map an extensive dataset. There is potential for analysing this data further and for producing additional mapping, for example, time series and coincidence mapping.

5.2 A wealth of historical data is available for water vole but regular re-surveys over large areas are costly and time consuming. Some Wildlife Trusts and other organisations have established local monitoring schemes, but there is no standard methodology or guidance available. In 2012 The UK Water Vole Steering Group agreed to explore the potential for developing a national water vole monitoring scheme. Work has now commenced on developing this programme, in association with PTES. 5.3 Work has commenced on identifying and mapping introduced populations. There is potential for using the process developed by the project to monitor the success of introduction schemes over time and to build up a picture of where introductions have occurred.

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References Bright, P.W & Carter, S.P (2000) Halting the decline: refuges and National Key Sites for Water Voles Report to PTES/EN. England Biodiversity Group (2008) Securing Biodiversity: a New Framework for Delivering Priority Habitats and Species in England. Natural England, Sheffield.

Strachan, R. & Moorhouse, T. (2006). Water Vole Conservation Handbook. Second edition.

Wildlife Conservation Research Unit, Oxford.

Telfer, S., Piertney, S.B. , Dallas, J.F et al (2003). Parentage assignment detects frequent and large-scale dispersal in water voles Molecular Ecology Volume 12, Issue 7, pp 1939– 1949, July 2003.

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Appendix 1 Water Vole and American Mink Distribution Maps

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Appendix 2 Water Vole Alert and Key Area Maps

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