the mammal society – for evidence based conservation – for

Mammal News Summer 2012 • www.mammal.org.uk

www.mammal.org.uk Summer 2012 • Issue 163

PIne marten conServatIon In england

and WaleS

exPlorIng batS’ SocIal netWorkS

reIntrodUcIng tHe eUroPean mInk

• Humpback whale visit • Urban foxes • Hedgehog survey update • Muntjac encounter• Moles: digging for a living; a new anatomical insight • Dormouse nesting tubes

INSIDE THIS ISSUE:

mammal neWS


03 Mammal matters

04 TMS Spring Conference and AGM 2012 Review

05 TMS Spring Conference 2013 and 2012 Events

06 Mammal Atlas

07 Hedgehog Footprint Tunnel update Summer 2012

08 Training News

08 TMS Shop

09 Book Reviews

09 Mammal Encounters

10 1st Mammal Society Student Conference Report

12 Pine marten conservation in England and Wales

14 Digging for a living; a new anatomical insight

16 Exploring bats’ social networks

18 Dormouse nesting tubes

20 The European mink

22 Through the tree-hole – Who lives in a tree like this?

Officers of the Mammal SocietyPresident: Dr Derek YaldenChairman: Dr Johnny BirksVice Chair: Adam Grogan Chief Executive: Marina PachecoHon Secretary: Kate WilliamsonHon Treasurer: Abigail BunkerConference Secretary: Dr Elizabeth Chadwick

MAMMAL NEWS is published by:

The Mammal Society, 3 The Carronades, New Road, Southampton SO14 0AA t: 02380 237874 e: [email protected] www.mammal.org.uk Registered Charity No. 278918

Editors: Dr Marian Bond and Hilary Conlan. Contributions to the next issue of Mammal News should be sent to the above address or email: [email protected] deadline is Friday 3rd August 2012Print & Design: Impress 01536 462888

Cover image: Pine marten. Photo by Ann and Steve Toon.

The opinions and points of view expressed in this newsletter do not necessarily reflect those of The Mammal Society or the Editor. Advertisements for services, products and other organisations in this journal are accepted in good faith. However, The Mammal Society gives no guarantees or endorsements of the services, products and other organisations nor that the advertisers will fulfil their obligations or claims. All rights reserved; no part of this publication may be reprinted or reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publishers. While every effort is made to ensure that Mammal News is published on the stated date and all advertisements and advertising matter appear correctly and in the issue requested, The Mammal Society cannot guarantee this and bookings are therefore accepted on this understanding. The Mammal Society cannot accept responsibility for transparencies or other contributions submitted on a speculative basis.

Mammal News Summer 2012 • www.mammal.org.uk2

Contents

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Mammals in the NewsRare visitorOn the 12th April 2012, a humpback whale was sighted in the Strangford Narrows, NI, possibly feeding on herring. Video footage enabled the Irish Whale and Dolphin Group (IWDG) to confirm identification of the species. While this is only the 4th validated sighting of a humpback whale, it is the 3rd consecutive year that a humpback whale has been recorded in Northern Irish waters. Humpback whales have a unique pattern on the under surface of their tails. Photos of this whale’s tail fluke would be particularly welcomed by the IWDG as it will help to ascertain if this individual is the same as was seen off Bangor in June 2011.

Urban foxes watch and researchCapturing the nation’s attention in May, the Channel 4 programme, “Wild in the City”, has enabled The University of Brighton’s ecology team, lead by Dr Dawn Scott, to

gather widespread data concerning the urban fox and public perception. This interactive programme enabled nearly 12,000 viewers to contribute to natural history research by recording their sightings and completing a survey. At present a broad data summary shows that although 86% of people living in urban areas say they like foxes, those that have the most frequent encounters were least keen on them. From the reported sightings and data from radio tracking individual animals, early estimations put the population of urban foxes at 40,000. This is a 20% increase from previous estimations and mirrors the growth of urban areas in the UK. Further analysis on all the data will be undertaken by the team at Brighton.

From urban to countryA rare black fox was photographed in Kneesworth, Cambridgeshire. Its unfortunate demise on a country road a few days later enabled Dr McRobie from Anglia Ruskin University to run DNA analysis. This confirmed that although it was a standard silver fox, one of its genes was a closer match to a Russian raccoon dog. In addition 2 previous unmatched mutations were found on one gene. Mutations are part of the natural diversity but interesting additions to the genetic information database.

Photo © MailOnline, by John Moore

I hope that by the time Mammal News lands on your doormat the weather has improved significantly from the strong winds and rain that we have been experiencing lately. The cold weather is bound to be affecting our mammals, especially after such a warm, dry spring, and we’d be very interested to hear from our readers if you have any weather related mammal stories. Come rain or shine though the work at the office goes on and we’d like to welcome two new interns, Louise Sleeman and Richard Austin. Louise is our new Atlas Intern so if you have any questions relating to getting atlas data to us please get in touch with Louise at [email protected], and Richard is our new Surveys Intern and all survey questions can be directed to him at [email protected]. We are entering our second year of the hedgehog footprint tunnel pilot study and we have changed the methodology to maximise survey time. The survey can be carried out only once, from now until September using only ten tracking tunnels. A brief report can be found on p7. If you would like to take part in this survey please let us know. We are also trying to work out a way of sharing tunnels

to keep the costs down and will keep you updated on our progress. This summer we have published the long awaited UK BAP Mammals: Interim Guidelines for Survey Methodologies, Impact Assessment and Mitigation. The driver behind this publication was the late Warren Cresswell, a long term, active member of The Mammal Society. He felt that whilst some UK BAP mammals (e.g. dormice, water voles, otters and bats) already had comprehensive guidelines on background biology, habitat requirements, survey methodologies, legal protection, impact assessment and mitigation, others, particularly those added to the UK Biodiversity Action Plan list in 2007, were lacking. He therefore convened a meeting of species experts to fill that gap and this book is the result. We are sure it will be of great use to consultants, academics and local authority ecologists. See p5 to order your copy.This edition also has a summary of the highly successful Spring Conference on p4. I’d like to thank Debbie Bartlett and the Chatham Campus of the University of Greenwich for hosting us this year. We really

enjoyed ourselves and, as usual, learned a lot, met up with old friends and made many new ones. For those of you who like to plan well in advance, the next Spring Conference will be held on 20th and 21st April 2013 at The University of Exeter. If you can’t wait that long we have a Regional Seminar in Scotland on Sunday 11th November and a South East Marine Mammals Conference at ZSL, also in November, full details can be found on our website. As I write this I am also looking forward to the first ever Student Conference, organised by the Student Committee, at The University of Reading on June 16th. Read the report on this on page 10.And last but very certainly not least it is our editor, Marian Bond’s, last edition. Marian has been editor of Mammal News for the last six years and we’d all like to thank her for the huge amount of time and dedication she has given to keeping the magazine interesting, informative and entertaining. Not only that but she found and trained her own replacement and we take great pleasure in welcoming Hilary Conlan as our new editor who will be going it alone from the autumn edition.

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I would like to introduce myself as the new Editor, taking over from Marian Bond this issue. I am currently working at Anglia Ruskin University, having come back to the UK last October from Tanzania. I was working as a field research assistant studying habituated baboon troops, elephants and vegetation monitoring in Mikumi National Park. Walking for 10 hours a day, surrounded by 50 baboons meant that I had the privilege of getting very close to all the animals in the park. Back in the UK, without the camouflage of habituated wild animals, I find watching British mammals more challenging but totally rewarding. Please send in your mammal sightings as they will spur me, and hopefully others, into getting out and about.

MATTERSMammal

Hilary ConlanNew EditorThe Mammal [email protected]

Note from The Editor

Photo ©

CP

RE

“This summer we have published the long awaited UK BAP Mammals: Interim Guidelines for Survey

Methodologies, Impact Assessment and Mitigation.”

Marina PachecoCEO, The Mammal Society, [email protected]


Dr. Marian BondCurrent EditorThe Mammal [email protected]

Mammal News Summer 2012 • www.mammal.org.ukMammal News Summer 2012 • www.mammal.org.uk4

News from The Office

The Mammal Society’s Spring Conference and AGM 2012 Review

This year the Mammal Society’s 58th Spring Conference was held at the University of Greenwich, Chatham Campus, Kent and was the biggest event for a number of years with approximately 170 delegates attending. Breaking with recent tradition, the event spanned two days, starting on Saturday morning with a talk from Ian Montgomery, with the first of a series of presentations from Queen’s University, Belfast. Ian’s talk, entitled ‘Impacts and consequences of small mammal invasions in Ireland’, highlighted how the non-native Greater White Tailed Shrew can have a detrimental impact on raptor populations. Although a prey species, they are a poor food source for raptor species, comparable to “junk food” in the raptor world. When a raptor’s diet consisted of mainly Greater White Tailed Shrew, a lower fledgling success rate was noted. Later in the day, Kent West gave an insightful talk looking back over 15 years of Kent Mammal Group. Ken pondered why there are not mammal groups in every county and expressed his hope that the success of the Kent Mammal Group would act as a template to ease the creation of new groups and enhance mammal conservation outcomes elsewhere in the British Isles.Liam Lysaght (National Biodiversity Data Centre in Ireland) gave an insight into the fantastic new dynamic GIS Atlas of Mammals in Ireland. Multiple species can be queried simultaneously, which is useful for

targeted conservation measures, and the whole package looked very impressive. The Cranbrook Lecture on Saturday evening was given by John Gurnell, emphasizing the complex and multidisciplinary nature of intervention projects using the conservation of red squirrels as a case study. He highlighted the often forgotten connection between the social science that intrinsically links the general public with on-the-ground conservation action and policy, bolstering the support for conservation initiatives. After this was the opportunity to

mingle at the Conference Dinner, which also saw the presentation of The Mammal Society Award for Outstanding Contribution to Mammal Conservation to Ken West, President of Kent Mammal Group.After the late night of the dinner, the talks on the second day provided welcome stimulation. One of my favorite talks of the weekend was given by Robyn Grant on ‘Active touch sensing behaviour in harbour seals’, or “whisking”. With the help of some clever technology, Robyn demonstrated how whisking strategies differ depending on the life of an individual. Joanna Bagniewska from the WILDCru at Oxford University presented interesting

findings from one of the few mink studies in the UK that is not related to their eradication. She used tiny Time-Depth recorders to measure diving patterns in the American mink. Research showed that mink dive most in daylight, with the smaller females diving more frequently than the larger males, and more times in a row than larger ones, suggesting that small female mink are poor at catching fish. Katie Colville from the Institute of Zoology followed with a thought provoking talk about assessing disease risks when reintroducing

species, using the example of the disease risk analysis for (hypothetical) wolf (Canis lupius) re-introduction in Scotland. The risk of introducing diseases via conservation programmes was highlighted by David Everest from the Animal Health and Veterinary Laboratories Agency. He discussed the sad tale of Adenovirus

and the catastrophic impact it is having on red squirrel populations. Richard Shore concluded the disease theme by introducing the Wildlife Disease & Containment Monitoring and Surveillance (WILDCOMS) network to facilitating the exchange of knowledge to enhance best practice and encouraging collaborations in the area of wildlife disease and contaminates.The weekend was rounded off with prize giving. The prize for Best Student Poster went to Sam Hardman for his excellent poster on a Novel Method to Aid Individual Identification of Common seals (Phoca vitulina) and the prize for Best Student Presentation, sponsored by Acorn

Ecology, went to Joanna Bagniewska for Measuring Diving Patterns of Small-bodied, Shallow-diving, Semi-aquatic Animals. Additionally, students attending to present papers or posters were awarded Michael Wood Bursaries to assist with travel costs. As ever, The Mammal Society team put a lot of work into organising the event. A big thanks goes out to Debbie Bartlett and The University of Greenwich for sourcing such a great venue and Mammal Society intern

Julia Tinker for providing a live Twitter feed for over 3,500 followers. Finally, a massive thank you goes to all the speakers and delegates for making the conference such a welcoming and inspiring event. I can’t wait for next year’s conference, hosted by Devon Mammal Group at Exeter University.

By Isla Hoffman-Heap

Sam Hardman being presented the winner of Best Student Poster prize by Derek Yalden

Audience at the conference

Ken West, medal winner, giving a speech

Sue Searle, Acorn Ecology, presenting

the Best Student Presentation to

Joanna Bagniewska

Mammal News Summer 2012 • www.mammal.org.ukMammal News Summer 2012 • www.mammal.org.uk 5

News from The Office

The Mammal Society’sSpring Conference 2013

We are delighted to be able to announce that the 2013 Spring Conference of The Mammal Society will be held on 20th and 21st April in the beautiful surroundings of The University of Exeter.Additionally, the 2013 Cranbrook Memorial Lecture which is free and open to all members of the public will take place at the University of Exeter on the evening of 19th April. All our recent events have sold out so we would strongly advise that you take advantage of the “members only window” and book before 31st October 2012.

First Call for Papers To present a paper or poster, send scientific programme coordinator (Elizabeth Chadwick) the following details: Title of presentation, Authors name, address and email address, an abstract of no more than 150 words. Please indicate whether you would prefer to deliver a poster or presentation. We are requesting electronic submissions only to [email protected] by 31st October 2012. Student bursaries and presentation prizes will be available, for details of these and the required abstract format, see the conference page at www.mammal.org.uk.

The Mammal Society 2012 EventsThe Mammal Society Regional Seminar10th November 2012, Newbattle Abbey College, Dalkeith, Nr. Edinburgh, ScotlandThe Mammal Society 2012 Regional Seminar will be in conjunction with Lothian and Borders Mammal Group. It will take place on 11th November 2012 at Newbattle Abbey College, Dalkeith Nr Edinburgh and will provide the usual great opportunity to get together with other mammalolgists and hear about the latest news. Speakers on the day include:

• Andy Riches, Scottish Badgers – Badger persecution

• Roisin Campbell-Palmer, RZSS – Scottish Beaver Trial update

• Karen Ramoo – Red Squirrels in South of Scotland

• Johnny Birks, The Mammal Society – Pine marten recovery and issues arising

South East Marine Mammal ConferenceZoological Society of London – Autumn 2012Delivered by Kent Mammal Group and ZSL, this conference will bring together experts and enthusiasts from the world of Marine Mammalogy, including Orca, The RSPCA, Seawatch and ZSL.

Full details will be available on the website shortly.

Lothians and Borders Mammal Group

(LaBMaG)


The distribution of the Yellow-necked Mouse highlights a particular difficulty, or if you prefer a particular challenge, for the new mammal atlas. In collaboration with Aidan Marsh, conducting his Ph.D. on the species at Bristol, members of The Mammal Society carried out a structured survey of woodlands throughout England and Wales, using Longworth live-traps. Habitat details were collated to try to explain which woodlands had Yellow-necked Mice, as well as Wood Mice, as compared to those that only had the ubiquitous species. The trouble is, the

survey work was carried out in 1998, so just previous to the proposed start year for the new atlas.So what is the distribution, now, of the Yellow-necked Mouse? The answer to this question will depend largely on live trapping. There might be a few sightings from animals invading houses, alive or caught in snap-traps, and even a few cat-killed mice to supplement these. The range of the Yellow-necked Mouse shares many similarities with that of the Hazel Dormouse: especially SE England, SW England and the Welsh Marches.

The two might also share dormouse boxes. One very exciting and very recent record is of a Yellow-necked Mouse in Cheshire, occupying a dormouse box at a reintroduction site on the county boundary.This is a species whose mapping will depend on the considerable expertise of members of The Mammal Society and of local mammal groups.Good hunting!

D. W. Yalden

New Mammal Atlas:Focus on Yellow-necked Mouse Apodemus flavicollis

Mammal Atlas

10km squares with records for Apodemus flavicollis (Yellow-necked Mouse) in Great Britain and Ireland© Crown copyright and database rights 2011 Ordnance Survey [100017955]

10km squares with records for Apodemus flavicollis (Yellow-necked Mouse) in Great Britain and Ireland, 2000 to 2012© Crown copyright and database rights 2011 Ordnance Survey [100017955]

This map is courtesy of the NBN Gateway and includes information from a large number of data providers. The full list of data providers is too long to list here, but can be found on the NBN Gateway at the following link http://data.nbn.org.uk/gridMap/gridMap.jsp?allDs=1&srchSpKey=NHMSYS0000080207* The NBN and its data contributors bear no responsibility for the further analysis or interpretation of this material, data and/or information.

6 Mammal News Summer 2012 • www.mammal.org.uk

New Mammal Atlas:Focus on Yellow-necked Mouse Apodemus flavicollis

7Mammal News Summer 2012 • www.mammal.org.uk

Hedgehog Footprint Tunnel update Summer 2012

The Mammal Society, together with Dr Richard Yarnell at Nottingham Trent University, with funding from PTES and British Hedgehog Preservation Society, started a pilot study for hedgehogs in 2011 in order to address the issue of reliably surveying for the species to get accurate data on numbers, in light of the anecdotal evidence of a decline across the UK. This study tested an innovative new survey method, the footprint tracking tunnel, which captures mammal footprints to ID which species have passed through and are therefore present in the area. Since last year, we have analysed the results, and have made some changes to the methodology as a result. We are now repeating the pilot this year under the revised guidance.

In 2011, the survey lasted 6 days each time, across three survey seasons, in Spring, Summer and Autumn. We also investigated whether 10 or 20 tunnels gave a better detection rate, and volunteers needed to alternate the number of tunnels placed between seasons to test whether tunnel density had an impact on detection rates. Volunteers were also required to carry out spotlighting surveys, where they walk a 100m line with a torch to spot hedgehogs.Overall, hedgehogs were detected in 58% of tunnel surveys, compared with being detected at only 29% of the spotlighting surveys at the same site, with analysis showing that season and number of tunnels have no significant effect on detectability. Five days was also found to be an optimum time for detection rates.

We have therefore concluded that the tunnels are an effective way to detect the presence of hedgehogs, with only 10 tunnels to be placed within each site, and each site to only be surveyed once. Several local groups are taking part this year, with a total of around 50 sites, which should ensure we can find significant trends and valid conclusions about the usefulness of tunnels to detect hedgehogs. If your local group would like to get involved, you have until September to do so. Please contact Laura at [email protected] for more information.

Laura Drake

Study Update

A hedgehog caught on a remote camera leaving its prints as it uses one of the tunnels. Photo by Richard Yarnell.

Online vs. Paper Mammal Review Subscriptions: Members’ Poll

If Mammal Review became online only, would you continue to subscribe?Moving to an online only subscription would not only save The Mammal Society money in printing and postage, but would be much more environmentally friendly as they would no longer be shipped here from Singapore. The subscription would still cost only £26 for the year, with each issue being emailed to you instead, and you would have access to back issues.

Before we make any decision, it is important to know what you our members think. Please either cut out this section of the magazine, tick the option you agree with, and send it to us or email me ([email protected]) with your choice.

Laura Drake, Membership Officer

I would continue to subscribe to Mammal Review if it became an online only subscription.

I would not continue to subscribe to Mammal Review if I lost the option of receiving a paper copy in the post.

Name: Email:

Any other comments:


The Mammal Society ShopIf you’re searching for a perfect gift for the mammal lover in your life, look no further. The Mammal Society has a range of publications ideal for enthusiasts and professionals alike. All of our books can be ordered at www.mammal.org.uk or by calling the Sales Office on 023 8023 7874.

Training News

Training NEWS

UK BAP Mammals: Interim Guidelines for Survey Methodologies, Impact Assessment and Mitigation

This new publication, co-produced by Cresswell Associates and The Mammal Society, is designed for ecologists and addresses standard survey protocols and guidelines for impact assessment and mitigation, in the context of an Ecological Impact Assessment (EcIA) for the following UK BAP mammals:

• Brown hare

• European hedgehog

• Harvest mouse

• Mountain hare

• Pine marten

• Polecat

• Red squirrel

• Wildcat

Price £15 (Mammal Society Members) or £19.90 (Non Members) Plus £ 2.95 P&P Remember, The Mammal Society has a range of publications ideal for enthusiasts and professionals alike. All our books and equipment can be ordered at www.mammal.org.uk or by calling the Sales Office on 023 80237874.

Edible Dormouse Ecology – 12th August Suitable for all levels of experience. This one day course in Tring covers a comparison between the two members of the dormouse family, Edible dormouse history in the UK, habitat requirements, ecology, its predators and the damage they cause. It will also contain a field trip to Glis Glis habitat to look for signs and will include an opportunity for seeing, photographing and handling wild GlisPrices for this course start from £46.75

Beaver Ecology & Conservation – 11th August (Knapdale) 15th September (Cotswold Water Park)Suitable for all levels of experience. Delivered by Dr Phoebe Carter at Cotswold Water Park and Roisin Campbell-Palmer at Knapdale Forest, this enjoyable one day course covers the ecology, biology, habitat, field signs and conservation, the course will also provide the latest news on the reintroduction process and, as it will be based in a reintroduction area, an opportunity to see the habitat and field signs in the afternoon. There is also the option to stay on into the evening which would increase the chances of seeing the beavers themselves – although this cannot be guaranteed. Prices for this course start at £80.75

With the majority of this year’s courses booking up well, we are starting to plan for 2013 and beyond. As ever, if you have any suggestions for courses you would like The Mammal Society to run, do get in contact by contacting Alex at The Mammal Society offices on 02380 237 874 or by emailing him at [email protected] are still spaces left on the majority of courses, but I would particularly like to highlight:

New8 Mammal News Summer 2012 • www.mammal.org.uk

Mammal News Summer 2012 • www.mammal.org.uk 9Mammal News Summer 2012 • www.mammal.org.uk

BookReviewsDonkey is one of a series of animal books published by Reaktion Books that explores the historical significance and impact on humans of a wide range of animals. Each book in the series takes a different animal and examines its role in history, mythology, religion and science and their place in the artistic and literary imagination. Each book is written by an author who is passionate about their subjects, and this is certainly the case with Jill Bough who has had a strong affection for donkeys since childhood. Donkey has a brief section on the natural history of the donkey explaining why its adaptation to the semi desert conditions of Africa, where they originated, makes them such useful beasts of burden. The majority of the book though explores the use and abuse of the donkey and its “offspring”, the mule, through the ages and explores the impact of the donkey on human agriculture, transport and culture. I was surprised to learn how reliant people have been upon donkeys, how wide their use was and how extensively they are still used around the world. The author is understandably concerned with donkey welfare as they are a much used and abused animal and this is a theme that runs through the book and influences her view when it comes to population control of feral donkeys in Australia where the author lives. All in all though, an interesting book on the considerable impact the donkey has had upon human civilization.

Marina Pacheco

Donkey by Jill BoughISBN: 9781861898036. Paperback, 200 pages, includes colour illustrations. Published: Sept 2011.

Hugh returns, after huge success with A Prickly Tale, with this new title that follows the people who spend their lives devoted to some of our most-loved animals, from bees and badgers, to dolphins and dragonflies, otters and owls. The introduction establishes how Hugh began this fascinating journey of discovery. In order to affirm his passion for hedgehogs, Hugh attended a mass public tattooing along with an eclectic collection of other people also willing to make permanent their devotion. After getting into conversation with others waiting in line, it led to Hugh asking the question “What was it that led to people becoming indelibly linked and incredibly inked with a particular species?” The result is Hugh uncovering a world of knowledge and experiences that have come from hours dedicated to learning almost everything there is to know about the animal in question. Divided into a chapter for each animal, this book is very easily digested and creates distinct stories that capture you, chapter by chapter. An informative, funny and endlessly endearing homage to the animals, and the people who work to understand and protect them, this book goes beyond a standard account of biology, ecology and conservation, to reveal the quirky characters, fascinating factoids and delightful descriptions that open our eyes to a new way of looking at familiar species. This is a book you can’t put down, that makes you want to know more and more about animals you may have barely considered in the past – it certainly does its job to reveal the true beauty in the so-called beast.

Laura Drake

The Beauty in the Beast by Hugh WarwickISBN 978-0-85720-395-3. Hardback, 320 pages, published: 2012.

Extended versions of these reviews are available at www.mammal.org.uk

Mammal Encounters

We had headed in to the depths of Thetford forest to try out a new camera lens, photographing plenty of vegetation and insects but no mammals. So finally, having captured a red admiral posing in the setting sun, we headed back to the car. As a muntjac trotted across the trail far ahead of us, we started to hear cars and knew we were coming to the main car park. Thirty meters in front of us in the dusky gloom, a large white animal appeared from the bracken. With its head down and away from us, we stopped still and came up with a variety of names it could be; judging from its shape, height and the fact that the light was very low, they ranged from huge dog to large sheep, before Trev finally glimpsed

the head of the apparition and excitedly whispered ‘it’s a fallow deer, a white one!!’. We managed to signal to Kate, who’d dropped back, to come quick and quiet with the camera and she blindly started taking pictures beyond us, not being able to see what it was we are so excitedly signalling to. The large white deer stopped and turned his big head to see us, we stood still and continued whispering ‘wow’ and ‘it’s a spirit animal’. He decided enough was enough, turned and ran through the bracken, across the road and disappeared into the forest. Research later that evening suggested a plausible explanation: 30 miles to the north of Thetford, Lord Cholmondeley of Houghton Hall near King’s Lynn has a

herd of over 1000 white fallow deer (http://goo.gl/7eNCi; and another sighting at bottom of page: http://goo.gl/HYW0O). Leah Collett, Trevor Jones and Katarzyna Nowak.

Mammal Encounters: Your storiesSpirit in Thetford

Spirit in the forest


Student Conference

1st Mammal Society

The 16th of June 2012 saw the very first Mammal Society Student Conference held at the University of Reading in Berkshire, an exclusive event for students studying mammals. The event was attended by 65 student delegates from across the British Isles, and over a dozen representatives from various charities and organisations.The keynote speaker, Dr Paul Chanin, started the day with a thoroughly engaging talk entitled ‘The accidental ecologist’. Dr Chanin, who has been a member of The Mammal Society for more than 45 years, talked to the students about his beginnings on a 100 acre farm in the Cotswolds, and how natural history and biology had gripped him from an early age, even setting up a natural history society in his secondary school and purchasing the first edition of The Society’s ‘Handbook of British Mammals’ at the age of 16. He then told how he went on to have along career with otters and dormice among other mammals as a student, assistant surveyor on various projects, lecturer and finally consultant ecologist. He gave the students valuable advice on what they needed to do to be able to compete in the jobs market, such as gaining field

identification skills, learning to question and be a problem solver, and of course become members of organisations such as The Mammal Society.The second speaker of the day was PhD student Amanda Wilson who studies

at the James Hutton Institute in Edinburgh. She gave a talk entitled ‘Wood mice habitat usage in space and time’, which was an extremely interesting look at an often underrated but important mammal, their spatial habitat

usage and genetic structure, and how they vary, in relation to agricultural practices and effects on biodiversity.Following this was undergraduate student Elizabeth Heasman, who gave a very well arranged and presented talk on ‘The benefits of set aside farmland for harvest mouse conservation’. Giving clear conclusions on how agricultural

land management can affect conservation measures, Beth presented a great piece of work overall.

After the break the second session opened with an engaging talk by PhD student David Oakley on ‘Camera-trapping, a multi-species approach to efficiently assess mammal populations in Britain’. Filled with amusing pictures of various camera-trapped animals, David also looked at how few mammal

records exist, and how many records are held in lots of different places but aren’t easy to access. He proposed camera traps, which for him provided hundreds of mammal records at one location, as one solution.MRes student Debbie Baird-Bower followed with her talk ‘Methods to study the foraging ecology of juvenile Southern Elephant seals’. Debbie explained the different diving behaviours of the seals and why it’s so important to understand these behaviours, as they are apex predators and have an important role in the marine ecosystem.Lunch followed, as did the poster presentations of which there were 11 posters by students ranging from undergraduates to PhD. There was a mix of ecology, environmental impacts and behavioural studies being examined and students had the opportunity to discuss their posters with others. The afternoon talks began with Cheryl Mills discussing the ‘Genetic population structure of the hazel dormouse’ which

Had a great time at the conference, great opportunity to meet people.Robin Searle, on Twitter

The Q&A panel experts (l-r): Pam Worrall, Dan Atter, Marina Pacheco, Paul Chanin, Sue Searle and Nigel Reeve.

I had a great time at the conference this weekend. Thanks for all your hard work, it turned out brilliantly!Ciara Powell, b7 email.

Student Conference - Report

Speakers (l-r): David Oakley, Beth Heasman, Andrew Robertson, Amanda Wilson, Cheryl Mills and Debbie Baird-Bower.

examined what effect habitat fragmentation had on the genetic population, followed by Andrew Robertson on ‘Individual foraging specialization in the Eurasion badger’ which gave an in-depth insight to how badgers have different foraging behaviours from one social group to another and also within social groups. Both PhD students and their talks were extremely engaging. At the end of the day, Cheryl won the Acorn Ecology first prize for Best Student Presentation, receiving £100, and Andrew won the Acorn Ecology second place prize of £50. Elizabeth Heasman’s talk was also Highly Commended and she received a copy of How To Become An Ecological Consultant, by Sue Searle of Acorn Ecology. Acorn Ecology Prizes for Best Poster were also given out. The winner of first place was Robin Searle, receiving £50, second place went to Suzanne Richardson, who received £25 and Ciara Powell was Highly Commended. All the day’s prizes were presented by Sue Searle. Following this, a panel of experts from various backgrounds talked about their career paths. They were Dr Paul Chanin, Marina Pacheco, CEO of The Mammal Society, Sue Searle of Acorn Ecology, Dr Nigel Reeve, Head of Ecology at the Royal Parks London, Dr Pam Worrall, Lecturer at Hadlow College and Kent Mammal Group Chairperson, and Dan Atter, Senior Ecologist at Thomson Ecology and Dormouse Officer of Berkshire Mammal Group. They gave out very useful advice to the students in a Q&A session. After a day of extremely engaging talks, students were able to take part in a careers fair and chat to various organisations, including PTES, Thomson Ecology, IEEM, BioTrack, RPS Ecology, Berks Bucks & Oxon Wildlife Trust, a range of mammal groups and The Mammal Society. A welcome wine reception followed where delegates had the chance to take part in some fun networking competitions to encourage everyone to mix and talk to each other. Four winners were selected and each received a £25 voucher from NHBS. The overall take home message from this conference was that students are an integral

and valued part of The Mammal Society membership, which continues to grow, and that they are important as the next generation of ecologists and conservationists in the British Isles. The conference provided an excellent opportunity for students to network, meet each other and learn more about mammal research being done elsewhere, and it also gave them some valuable tips to be successful in their chosen fields of research and career. We would like to thank Reading University

and the Cole Museum of Zoology on campus for hosting the event; a superb venue providing a suitably zoological backdrop to the day’s events.Overall the first Mammal Society Student Conference was seen as a great success by all and preparations are already underway for a

second one next year. Watch this space!

Article and photos by Keri Russell

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Student Conference

Lots of interesting talks at the Mammal Society student conference!Ryan Clark, on Twitter

Students mingling during the careers fair.

Had a great time and learned loads, thank you! :)Rachel Dolan on Facebook

Winners of the Acorn Ecology prizes for Best Presentations and Best posters, with Sue Searle. (l-r): Cheryl Mills, Suzanne Richardson, Robin Searle (front), Andrew Robertson, Beth Heasman and Ciara Powell.

You can keep up to date with The Mammal Society by liking our Facebook page and following @Mammal_Society on Twitter.

On the trail of the lonesome pine: Pine marten conservation in England and Wales

The pine marten is arguably the most elusive carnivore in England and Wales. Forced to retreat to isolated forests and rocky outcrops by deforestation and persecution, few people are ever lucky enough to catch a glimpse of one. Whilst pine marten populations are recovering well in Scotland, populations south of the border have not shared this success and appear to persist only at very low densities in remote areas of England and Wales. It is this situation that prompted The Vincent Wildlife Trust (VWT) to begin investigating the distribution and status of pine martens in England and Wales over 30 years ago. The Trust’s work to date has primarily involved trying to track down this mustelid in England and Wales, through collecting and evaluating third party sightings and collecting pine marten DNA through field surveys and unequivocal records (e.g. carcasses of roadkills and preserved specimens). In order to detect populations at such low densities, the Trust has experimented with a variety of different field methodologies. Advancements in DNA analysis have allowed scats to be verified by DNA-typing and consequently scat surveys have been used frequently as a method of detecting marten presence. Baited hair-tubes have been trialled, with collected hairs subjected to DNA analysis. Remote camera traps, cage traps and scent lures have also been investigated with limited success, so rare and elusive are pine martens in southern Britain that only 17 unequivocal records of the species have been confirmed in England and Wales

since 1990. An unequivocal record refers to a sample confirmed by DNA analysis (e.g. a scat or hair), a specimen examined ‘in the hand’ or a clear photograph. Alongside these records, the VWT has been collecting pine marten sightings reported by members of the public, naturalists and professionals. In order to reduce confusion and misidentification with species of similar appearance, these sightings are evaluated based on the description of the animal and the knowledge and experience of the observer, and allocated a confidence score accordingly. The higher scoring sightings corroborate with the unequivocal evidence and together they illustrate that pine martens are persisting in the Lake District, Northumberland, North Yorkshire, the Peak District, areas of mid and west Wales and Snowdonia. The results of this work have been published in a report entitled Evidence of Pine Martens in England and Wales 1996-2007, which is available to purchase from The Vincent Wildlife Trust.Another focus of the Trust’s work has been investigating conservation measures to help pine martens recover, notably, the use of purpose-built pine marten den boxes. Once erected on trees, den boxes provide artificial resting sites that help to compensate for the absence of large tree cavities which martens favour as natural den sites. The boxes provide a safe place for female martens to raise their young and for martens to shelter from the elements. Their elevated position also helps pine martens avoid intraguild predation by foxes. Recently, the Trust decided to investigate

the origins and persistence of pine marten populations in England and Wales, in order to inform future conservation management strategies for the species. Samples were taken from both contemporary populations (scats and carcasses found since 1981) and historical populations (samples pre-1950 preserved as mounted taxidermy, skins or skulls) from England, Wales, Scotland and Ireland. Geneticists at Waterford Institute of Technology (WIT) identified mitochondrial DNA sequences from these samples in order to determine the haplotype. A haplotype is a group of DNA sequences of different genes that are often associated with specific geographic areas and can therefore provide some clues as to the geographical origin of the samples. All 13 samples collected from England and Wales from historical populations (1864-1950) were identified as originating from haplotype i animals. By contrast, none of the 14 samples collected since 1990 were of this type. Instead, the majority of recent samples collected from across England and Wales were of haplotype a, which is the predominant haplotype found in the present-day population of Scotland. As well as these haplotype a samples, two recent samples from the north of England showed introgression with American martens (Martes americana) and two further samples originated from haplotypes found on mainland Europe. We can be reasonably sure that one of these European samples- a marten found dead on a road in Hampshire- had escaped from captivity, but nothing is known of the origin of the second sample.

Lizzie Croose, The Vincent Wildlife TrustPine marten. Photo by Colin Smith

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Therefore, although the number of samples is small and future material may surprise us, it appears that in England and Wales, the predominant historical haplotype (i) has been replaced by contemporary populations dominated by individuals of haplotype a. These DNA data suggest that historical populations of pine martens may have been lost from England and Wales at some point in the early to mid 1900s and have been replaced by, or hybridised with, occasional released, escaped and/or translocated pine martens from elsewhere. In northern England it is possible that some recent haplotype a records are the result of individuals dispersing from populations in southern Scotland, but that does not explain the occurrence of haplotype a animals further south or in Wales. These genetic results have important implications for the future approach to the conservation and population recovery of pine martens in England and Wales. In particular, when it was suggested previously (in the late 1990s) that pine martens should be reintroduced to parts of England, this proposal was opposed partly on the grounds that potentially unique populations may be vulnerable to genetic dilution. This new evidence, however, suggests that this may no longer need to be a consideration, as the relict genetic stock of pine martens in England and Wales may have already been lost. Reintroduction would therefore now be an acceptable route to restoring pine marten populations to England and Wales, should such a restoration be deemed necessary and desirable.The results of this genetic research, combined with the culmination of nearly two decades of recording and other work, led to the completion of a Pine Marten Conservation Strategy in 2011. The strategy has been produced by The Vincent Wildlife Trust in collaboration with 12 stakeholders including other conservation organisations, statutory nature bodies and game and forestry groups. It highlights priority areas for research and conservation that need to be addressed in order to restore self-sustaining populations of pine martens to England and Wales. The strategy discusses two potential mechanisms for restoring self-sustaining populations of pine martens to England and Wales: firstly, indirect intervention to promote natural recovery of populations; or secondly, direct intervention through reintroduction or restocking. Firstly, current populations may be encouraged and allowed to recover semi-naturally via intervention, principally by fixing limiting environmental and/or anthropogenic factors. A high priority is determining why pine martens are not recovering in England and Wales in the way that they are in Scotland and Ireland. A key objective outlined in the strategy is the promotion of targeted creation and expansion of

woodland, specifically that which provides suitable natural den sites and diverse prey for martens. Linked to this is the production of guidelines on management of woodland for pine martens and investigating the artificial creation of tree cavities as den sites. To aid this task, a comparative factor study should be undertaken in order to compare the habitat and other environmental and anthropogenic factors that may impact on pine marten populations in England, Wales, Scotland and Ireland. Further priorities in the strategy include continuing to develop and improve detection methodologies for monitoring pine martens and undertaking a national pine marten distribution survey of Scotland to establish where the species has spread to since the last survey in 1994. A socioeconomic study of the potential impact of pine martens would also be a beneficial exercise if they are to become more numerous in southern Britain in the future. Secondly, direct intervention by means of reintroduction or restocking may be considered. There is potential for pine

martens in southern Scotland to disperse into the north of England and restock Cumbria and Northumberland. However, it is unlikely that pine martens could spread naturally to Wales or southern England for a very long time; hence reintroduction or restocking may be deemed necessary here. IUCN guidelines state that previous causes of decline should be identified and eliminated or reduced to a sufficient level prior to any reintroduction and, given the probable factors limiting pine marten recovery, it may be some time before we are in a position to advocate the reintroduction or restocking of pine martens to southern Britain. In the meantime, we must focus on doing all we can to help those remnant populations still surviving in the remote corners of England and Wales.

If you have seen a pine marten in England or Wales, please contact The Vincent Wildlife Trust via www.vwt.org.uk or by phoning 01531 636441.

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Pine marten. Photo by Ann and Steve Toon

The pine marten is arguably the most elusive carnivore in England and Wales.

Digging for a living; a new anatomical insight

The death of King William III in March 1702 is attributed to a fall from the King’s favourite war horse, Sorrel, which had tripped on a mole-hill, a pile of spoil brought to the surface by a busily tunneling moldewarp (Figure 1).Moldewarps, an old name for the mole Talpa europaea, are highly accomplished miners and within their solitary territories they dig a complex, branching, 3-dimensional network of permanent tubular tunnels from which they obtain their daily ration of soil invertebrates. In an established territory there can be hundreds of metres of tunnels at various depths in the soil column, some as deep as 1.5 metres.When digging a new tunnel, the mole shears the soil from the work face with alternate forepaws, its body being braced securely in the tunnel with the hind-limbs and the inactive fore-limb. The excavated soil is swept back down the tunnel by the active fore-paw and by scrabbling movements of the hind-paws.

When the mole judges that enough spoil has been accumulated, it turns within the tight confines of the tunnel. It then uses one fore-limb in the manner of a bulldozer blade to push the spoil back down the tunnel until it reaches a previously dug shaft leading from the tunnel to the surface. The soil is pushed up this sloping shaft and out onto the surface to create the molehill so beloved by all gardeners and green-keepers. At some point of course, it becomes energetically sensible to dig a new lateral shaft to the surface rather than to push the spoil ever further down the lengthening tunnel. The spoil from the new lateral shaft is packed into the previous, now redundant shaft. The result of all this unseen labour is a row of mole-hills marking the route of the tunnel. You can see a video of mole digging at www.bbc.co.uk/nature/life/European_Mole#p007qwt5.Digging is prodigiously hard work and energy consuming; digging 1 metre of tunnel can use, depending upon the soil conditions, 400-4000 times as much energy as walking the same distance on the surface. Little wonder then, that the collective noun for a group of moles is a labour, and hardly surprising, that the mole shows quite spectacular adaptations that serve to enhance its digging capabilities. The most striking of these are modifications to the skeleton that serve to provide an efficient digging tool for shearing and shifting soil and to provide the very high forces that are

required. The resultant strength of small fossorial mammals is truly prodigious; for example, the Eastern American mole Scalopus aquaticus has been measured exerting a force equivalent to 32 times its own body weight and a 57 g golden mole is on record as having escaped from captivity by moving aside a 9.5 kg iron lid!As we have seen, moles dig with their forelimbs and it is these that show the most extreme anatomical changes (Figure 2).

The shoulder blades, the scapulae, are long and thin and lie almost horizontally along the mole’s back. The collar bones, the clavicles, are short and robust so that the shoulder joints lie very far forward, close together, and low down under the neck.

The upper arm bone, the humerus, is highly adapted and is a massively built bone with complex and strong muscle insertions. Its orientation is as bizarre as is its morphology; instead of hanging down from its articulation with the shoulder, as it does in most mammals including ourselves, in the mole it points upwards and outwards! The broad humerus is rather like a sagging door, hinged only at the bottom and leaning out at the top, away from the door-jamb. The elbow joint is orientated so that the fore-arm sticks out sideways from the upper (anatomically lower) end of the humerus, with the hand held vertically and with the palm facing backward, ready to sweep across the tunnel wall.The major muscles responsible for the digging stroke are large and attach to the outer edge of the humerus or, to continue with our door analogy, to the edge with the door handle. The other ends of the muscles insert mainly on the breastbone and the shoulder blades. When the muscles contract they cause the humerus to rotate around its long vertical axis, exactly in the manner of opening a door. The result is that the forearm is pulled backwards in a horizontal, sweeping movement, delivering a powerful out-force to the hand for digging.The hand itself is very large, broad, thick and webbed, with the digits, apart from their powerful claws, largely hidden beneath the extremely thick and tough skin (Figure 3). The hand has an anatomical

Martyn L Gorman, Reader in Zoology, University of Aberdeen

Mammal Research

Figure 1. Gardeners, be afraid, be very, very afraid. An exceptionally large mole-hill. Photograph by Martyn Gorman.

Figure 2. The fore-limb skeleton of the European mole. Photograph by Martyn Gorman.

As we have seen, moles dig with their forelimbs and it is these that show the most extreme anatomical changes.

14 Mammal News Summer 2012 • www.mammal.org.uk

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surprise in store – it appears to have six digits! The extra digit lies anterior to the thumb, to its outside and completely enclosed within the web, and serves to increase the surface area and rigidity of the spade-like hand and to reinforce the edge lying on the soil, thus increasing its efficiency as a digging apparatus.Most pawed mammals are, of course, pentadactyl with 5 digits on each paw. Polydactyly, the possession of extra digits does occur in many species, including humans, but only as a relatively rare genetic syndrome. Among the talpid moles of the northern continents, however, an extra ‘thumb’ on each hand is the norm rather than a developmental anomaly. Recent research has now thrown new light on the intriguing question of how talpid moles have managed to overcome the almost universal pentadactyl constraint. An international team of researchers headed by Marcelo Sánchez-Villagra, a professor of paleontology at the University of Zurich, have used molecular markers to study the origin and embryological development of the mole’s extra ‘thumb’.Unlike the other fingers on the mole’s hand, the extra thumb consists of a single, sickle-shaped bone, without moving joints (Figure 4). The bone is variously known as the os externum or the prepollex, but more usually as the os falciforme. It has no claw, and it lies completely encased within the skin of the hand. Although un-segmented the falciform bone can be moved independently around its articulation with the wrist, just like a normal digit, so as to widen the hand, using the Musculus

abductor pollicis longus and M. palmaris longus muscles. Many groups of vertebrates have accessory bony structures in their hands and feet, usually associated with the radius of the fore-leg or the tibia of the hind-leg. In the case of the mole, the extra thumb-like skeletal element in the hand is a massively enlarged sesamoid bone associated with the radius bone where it articulates with the wrist bones. (A sesamoid bone is normally a small bone that functions to anchor tendons.) The mole’s radial sesamoid develops later than true digits but during embryonic development it becomes incorporated into the normal series of digits. There is a final twist to this tale! The research has revealed that the mole’s rear paws are similarly adapted and equipped with an extra un-jointed ‘toe’ (Figure 5) that helps the mole to firmly anchor itself within its tunnel whilst digging! Again, the extra ‘digit’ is an enlarged sesamoid bone but this time one associated with the tibia.In essence, by recruiting their wrist and ankle sesamoids to act as honorary digits, moles have successfully circumvented the otherwise almost universal constraint of 5 digits per paw in an evolutionary bid to maximise the efficiency with which they dig.

References:Christian Mitgutsch, Michael K. Richardson, Rafael Jiménez, José E. Martin, Peter Kondrashov, Merijn A. G. de Bakker, and Marcelo R. Sánchez-Villagra. Circumventing the polydactyly ‘constraint’: the mole’s ‘thumb’. Biol. Lett. February 23, 2012 8 (1) 74-77.

Figure 4. Micro-tomography scans of the right hand and foot of a talpid mole. The radial and tibial sesamoids are shown in a darker colour. Courtesy of the University of Zurich.

Figure 5. The right hind paw of a mole. The clawless 6th ‘digit’ can be clearly seen on the left side of the foot. Photograph by Martyn Gorman.

Figure 3. The right hand of a mole. The 6th ‘digit lies hidden beneath the webbed palm, to the right of the thumb. Photograph by Martyn Gorman.


Mammal News Summer 2012 • www.mammal.org.uk16 Mammal News Summer 2012 • www.mammal.org.uk

Exploring bats’

Each night during the summer, bats leave their roosts shortly after sunset to forage for their insect prey, returning once they have eaten their fill or the dawn approaches.Tree-dwelling bats typically change where they roost every few days, making it difficult to study their roosting behaviour. They typically come together in groups of tens to hundreds of individuals and it has been suggested that when they change roosts, they do so as a group. During five years of research at Wytham

Woods in Oxfordshire, we tried to investigate just this. What is the social structure of a bat population? Who hangs out with whom? And do different social groups keep their distance from one another?Wytham is a 400-hectare semi-natural ancient woodland, owned by The University of Oxford. It is one of the most intensively studied ecosystems in the UK, if not the world, and is home to famous studies, of passerine birds and tawny owls as well as small mammals, badgers and deer.

What makes Wytham a unique study site for bats is the sheer number of potential roost sites that can be easily studied. Woodcrete bird boxes put up over the past 60 years, for the study of blue tits and great tits, have become regular roost sites for bats, particularly Daubenton’s (Myotis daubentonii) and Natterer’s bats (M. nattereri).Over the past six summers, researchers from the Centre for Ecology & Hydrology in Wallingford, The University of Exeter and The University of Oxford regularly checked the boxes for bats, with help from local volunteers. When we found one, we fitted an aluminium ring with a unique identification number on its forearm before returning it to its box.By monitoring where each bat was found and with whom it was found, we could explore the social networks of the Daubenton’s and Natterer’s bat populations, building up a picture of which bats were continually found together and which seemed to avoid each other.This kind of social network analysis is more often used on human populations, for purposes like predicting who might be infected during a disease outbreak. It’s also behind the study that gave us the idea of ‘six degrees of separation’, whereby any two people in the world can on average be connected to each other through six other people in a ‘friends of friends’ chain.Social network analysis has only recently

Written by Tom August, Co-authors: Miles Nunn, Danielle Linton and Fiona Mathews

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social networks

Lorraine Broaders examines the wing membrane and ring of a bat in Wytham. Photo by Christos Astaras

A Natterer’s bat (Myotis nattereri) with its unique aluminium forearm ring. Photo by Keith Cohen

A box full of Natterer’s bats in Wytham Woods. Photo by Fiona Mathews


been applied to the study of wildlife populations but is already producing fascinating results.Our Wytham study found that both Daubenton’s and Natterer’s bats form complex social networks, but that the structure of these networks differed between species.Natterer’s bats formed well defined social groups – collections of individuals of both sexes who were repeatedly found roosting with each other. Within the wood were six social groups, and while individuals from the same group were regularly found roosting together, individuals from different social groups were very rarely seen together.

Daubenton’s bats showed this structure only among females, which formed four social groups. Male Daubenton’s are known to spend much of their time roosting away from females in bachelor colonies, and the research at Wytham found that while these males did occasionally roost with females, particularly during the autumn, most were not faithful to a single female group.The tight-knit social groups we found probably have a number of benefits for their members. These may include grooming, avoiding predators and sharing body heat or information about where to find food or roosts. It is possible that the individuals in a group are related, so by helping each other they are helping their kin. The Wytham study didn’t stop at social structure. Using the data on which boxes individuals were found in, we mapped the roosts used by each social group. By doing this it was possible to get an idea of the area of woodland used by a social group for roosting.The area used for roosting by each of the six groups of Natterer’s bats rarely overlapped. These group-specific roosting areas were relatively small, with the average territory measuring only 23 hectares (though this is probably an underestimate). Similarly, the roosting areas used by the female social groups of Daubenton’s bats were also small, averaging 17 hectares, with little overlap. The groups of both species probably foraged over much larger areas than they chose to roost in.There did not seem to be any competition between the two species. While social groups within species did not have overlapping roosting areas, groups belonging

to different species overlapped considerably.To check our results from box checks, we radio tracked a few bats and monitored their movements. Reassuringly, the bats spent the majority of their time roosting within, or close to, their group’s area as previously

identified through the social network analysis.These results highlight a number of important features of the ecology of these bat populations. They break down into social groups with restricted membership. This supports the current practice of ensuring rescued bats are

released near where they were found so that they can rejoin their social group. Groups also use relatively small areas for their roosting needs, compared to the distances they will fly at night to forage and the size of Wytham Wood. This reliance on a network of roosts in a small area means these groups might be vulnerable to what seem like minor habitat changes. The needs of bat social groups should therefore be considered when altering their habitat to ensure minimal impact.These kinds of investigation into bats’ social structure are allowing us to ask new questions about their ecology. How do diseases spread through their populations? What are the foraging and roosting requirements of a social group? Why do different species have different social structures?Work on bat social networks has undoubtedly raised more questions than answers. However, with continued technological advances in GPS and radio tracking devices and developments in the statistical analysis of social networks, the future of this field looks exciting.

Mammal Research

Volunteers in Wytham Woods. Photo by Andrew Harrington

A bird box hanging on one of the many old oak trees in Wytham Wood. Photo by Danielle Linton

What makes Wytham a unique study site for bats is the sheer number of potential roost sites that can be easily studied.

A group of very happy volunteers... and one lucky man! Photo by Stuart Jenkins

Mammal News Summer 2012 • www.mammal.org.uk18 Mammal News Summer 2012 • www.mammal.org.uk

There are many things we should thank Pat Morris for – devising and producing the Mammal Society Newsletter for many years is one (the precursor to Mammal News), not to mention encouraging Annabel Whittet to publish a series of excellent books on mammals and contributing two himself. However, for me, the most helpful thing he ever did was to invent dormouse nest tubes.Originally intended for edible dormice Pat and Ruth Temple devised and tested nest tubes based on the plastic guards used to prevent browsing damage to young trees. By

sliding a plywood tray inside with a vertical end piece to make a cavity, and attaching these to branches, they created a cheap (and light) alternative to the solid wood nest boxes normally used. They were quite large (about 80mm x 80mm x 600mm) but proved to be very effective.The design was readily adapted for hazel dormice by using smaller tubes and inserts (ca 50mm x 50mm x 250mm) and these are now mass produced in kit form and sold via the Mammal Society Shop – at the bargain price of £2 each.Nest tubes, together with nest boxes form the basis for collecting a great deal of interesting information about dormice. Tubes are particularly good for doing dormouse surveys and are widely used by consultants to answer the question ‘Are dormice present?’. Nest boxes are best suited to long term studies of dormouse ecology, most notably within the National Dormouse Monitoring Programme (NDMP).I have 3-400 tubes in a shed at the bottom of my garden which get used for surveys during the summer. They are light and easy to carry – 100 at a time is not difficult, quick to put up and quick to inspect. Thank you Pat!

In 2002 Michael Woods and I organised a survey of over a hundred sites in southwest England, using volunteers to install and inspect tubes. We found dormice in about a third of these sites, including some apparently unlikely ones such as conifer plantations and heavily managed hedges. One interesting finding was that dormice were detected in three out of seven coniferous woods but only three out of 20 deciduous woods. We suspected that this was because there are a lot more natural nest sites in deciduous woodland so

Paul Chanin, Mammal Ecologist

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Nineteen out of twentydormice...

Hibernating dormouse. Photo by Paul Chanin

Nestbox position. Photo by Paul Chanin

Nesting material. Photo by Paul Chanin


dormice are less likely to use the tubes in that habitat.Since nest boxes are readily used in woodland and are also frequently used for breeding (unlike tubes) it seems that dormice use tubes and boxes in different ways. The pattern of use of tubes is such that they are mainly used during May before the main breeding season and in August and September when young from the first litters are dispersing.In 2007, Leonardo Gubert and I started a four year study of dormice living beside and on the central reservation of the A30 in Cornwall. First discovered by Matt Pickard, who ignored suggestions that it was a silly place to look, these dormice live in a highly fragmented landscape with rather small patches of habitat split up by roads. Leo and I felt that it would be a good place to find out how they manage this and were able to persuade English Nature and the Highways Agency to support a study there.We put up 100 nest boxes but, because it was easy to do and might provide additional or different information, we also put up 200 tubes interspersed with the boxes at 10m intervals. It wasn’t our intention at the start but we eventually realised that we were also conducting a choice experiment to see whether dormice preferred boxes to tubes and whether this changed through the year. Over the four years of our study we marked 62 dormice (using microchips) and had nearly 50 ‘recaptures’ of them. Only thirteen captures were in tubes and since there were twice as many tubes as boxes, the suggestion that ‘When asked, nineteen out of twenty dormice preferred nest boxes to nest tubes’ is a fair approximation. However that picture does not represent the full story. As well as the 13 dormice found in tubes, we recorded 17 empty dormouse nests which shows that dormice had used them but doesn’t tell us which dormice. We sometimes found dormouse nests in boxes

without occupants but it was much less frequent and in some cases we found that they were occupied at a later date – which didn’t happen with tubes. This suggests that tubes might be used for shorter periods of time than boxes.The numbers were too low for statistical analysis but we did find that tubes were used mainly in April, May and September whereas boxes were used throughout the year with a peak in May. We also found that dormice were more likely to use tubes in one of our habitat fragments than the others. There were no detectable differences between the sexes but we didn’t find any juvenile dormice in tubes.We can conclude then that dormice use boxes and tubes in different ways and also that given a choice, dormice will normally use the larger boxes. This must be particularly important for females rearing young when space will be at a premium as the young develop. Certainly reports of litters of dormice in tubes are extremely rare. You can get more adults in too – Leo and I once found an adult male with three females in a box – though I have never seen more than two adults in a tube.I suspect that dormice use the tubes as temporary camps rather like badger outlying

setts. I once found six nests in tubes along a distance of only 120m beside a road and four consecutive tubes – spaced out at 15m intervals – all had nests in at one time or another during the season. It seems extremely unlikely to me that this was four different dormice but quite plausible that they had found a good food supply in a tree or shrub with a nest tube nearby and simply set up camp there for a while, as they polished off the goodies.This emphasises the point that, where there is a choice, dormice might use boxes for preference but we shouldn’t conclude that tubes are useless for surveying. In fact tubes have a number of advantages. Their cheapness and lightness mean that it is much easier to survey large areas with them than with boxes. More important is the fact that we have a well established protocol for using tubes which enables us to provide a measure of survey effort. We know that tubes are used more in some months than others so by giving a weighting for each month we can assign a score to a survey based on timing and the number of tubes. I for one will continue to use tubes for surveys and continue to thank Pat for this simple, but very effective, solution to the problem of finding out where dormice live.

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Nestbox accessibility. Photo by Paul Chanin

Nestbox in use. Photo by Paul Chanin


Reintroduction of a critically endangered mustelid

It sounds strange – reintroduction of mink in Europe? The invasive North America species originally escaped (or was released illegally) from fur-farms and nowadays is considered to be a pest. The similarities in appearance and way of life led to the North American species and the native European mink Mustela lutreola being confounded. This has resulted in the European mink becoming one of the most endangered and least-known mammals on the European continent.The European mink belongs to the group of small mustelids. With a head-body length of 30 - 43 cm and body mass of 500 – 1000 g, its size places it between the ermine M. erminea and the polecat M. putorius. Its fur is uniformly dark-brown, with white marks on both upper and lower lips. As a semi-aquatic habitat-specialist, it settles

in near-natural banks of small rivers and creeks, lake-shores, in fens and carrs and requires a large variety of shelter and prey (small mammals, fish, amphibians and invertebrates) to sustain it. Its non-native counterpart – the American mink Neovison vison – is larger than the European mink, more flexible in habitat selection and

especially highly reproductive, facilitating a rapid spread into new regions. Thus, in comparison to the European mink, the American mink is a more successful colonizer, even of harsh, rocky shores like in Iceland.

The habitat-specialisation of the European mink became its doom. Human clearing of riparian forests, drainage of wetlands and regulation of rivers seems to have been the main reasons why it was already reported as uncommon at the middle of the 19th century. Today, only small, widely-scattered populations persist, in Spain, France, Belarus, Romania and Russia. Now awareness of the need to preserve and expand riparian and wetland habitats should assist the European mink. However the introduction and spread of the American mink in Europe is now the main threat. Being a larger and a stronger competitor, it can displace the native mink.The rapid decrease of European mink is ongoing. Recently, its status was further tightened to ‘critically endangered’ (www.iucnredlist.org). Even such well-known threatened species like the Amur-tiger are still only considered as ‘endangered’. If we do not want to lose the European mink in the near future, combined recovery and conservation measures are urgently required. One measure being undertaken is their breeding in captivity within the European Endangered species Programme EEP (see www.lutreola.ee). This is also the basic requirement for

reintroductions, in producing the founder animals for release.In 2006, together with several partners, we started a reintroduction of European mink in south-western Germany. The non-profit association EuroNerz e.V. (www.euronerz.de) is a member of the EEP. It maintains a breeding stock of 70 European mink and provides the founder animals. Our first aim is to re-establish a population of European mink. In addition, we still need to know more about its behaviour and habitat use as well as the optimal methods for release and monitoring. Therefore, intensive scientific research to accompany the project is being led by Elisabeth Peters and Ina Klaumann (www.nerzforschung.de). The project is funded by the Ministry of Environment of the Saarland, the Saartoto GmbH and the HIT-Umweltstiftung.

The core-site for the reintroduction is a nature reserve, formed by a network of about 140 km of watercourses, the river Ill and its tributary streams. Here, especially the bank-zones are protected and left almost undisturbed. Moreover, the successfully reintroduced beaver Castor fiber albicus increases the diversity of habitat, shelter and prey also for the European mink by building dams and retaining streams.Prior to release, all European mink are individually marked with microchips for identification at re-trapping or if they are

Christian Seebass, EuroNerz e.V., Borgloher Str. 13, 49176 Hilter a.T.W.; E-Mail: [email protected]; Internet: www.euronerz.de Elisabeth Peters, Kurze Str. 12, 49080 Osnabrück; E-Mail: [email protected]; Internet: www.nerzforschung.de

Mammal Research

The European minkEuropean mink. Photo by Florian Moellers

Characteristics of the European mink: A uniformly dark-brown fur and white marks of upper and lower lips. Photo by Florian Moellers

Reintroduction in south-western Germany: Undisturbed streambanks with much shelter and prey. Photo by Florian Moellers

The alien American mink. Photo by Florian Moellers

Mammal News Summer 2012 • www.mammal.org.ukMammal News Summer 2012 • www.mammal.org.uk 21

found dead. Some are also equipped with implanted radio-transmitters to track them after release.Reintroduction attempts often face the problem that released animals tend to disperse quickly over long-distances, exploring their new environment for food, shelter, conspecifics and potential harassment. This behaviour puts such animals at high risk of being killed by traffic or predators. Therefore, release methods should aim to create a ‘sense of home’ in the animals to prevent early migration.One important aspect is a period of adjustment before release. During a 14 day phase we condition the European mink in enclosures directly at what will become their release site. They are able to get used to the conditions, sounds and smells of the region and are given the opportunity to catch their natural prey. After the adjustment period they are released either directly from the enclosure or by using artificial dens set up on the river banks. A European mink is placed into a den, which is opened after 1 or 2 hours. This allows the animals to calm down and accept the den as a secure shelter. A second aspect is the choice of animal and season for release. In our project, we released pregnant female European mink in the spring, when they should be hormonally motivated to settle down. With the aim of inducing a social relationship, we released mated couples in the spring. In the late summer mothers with their almost full-grown litters were released. Since 2009, almost full-grown cubs have been released in

autumn of their year of birth; this is designed to encourage them to establish their own territory for overwintering.After release, the real work starts. The post-release monitoring aims to collect scientific data and to check if the animals are able to survive. From 2006 to 2009 we used mainly radio-tracking and live-trapping. Both methods need considerable time and manpower. Therefore, since 2009 we have shifted towards the detection of European mink presence. Now we use special wildlife cameras (Cuddeback® Capture) and baited hair-traps, where mammals leave hairs on sticky tape while taking the bait. The hairs are then identified to species level by light-microscopy, as described by García and Mateos (2009) in Small Carnivore Conservation.From 2006 to 2011, a total of one hundred and twenty-five European mink were released (56 males, 69 females). Fifty-nine animals were radio-tracked. Of these, at least twenty animals were able to establish a territory. Also, in winter, several European mink were present in the project area. The females released during pregnancy gave birth to at least eighteen cubs. In 2008, a female cub without a microchip was caught, most probably born to a female which had been settled in the area since 2007. It was one of the first cubs sired and born in the wild. All these data are minimal numbers, because only half of the released animals were radio-tracked. In addition, the monitoring of such a small, cryptic species is not easy, even with technical help (see below).The monitoring revealed that the European mink were able to adapt to the conditions

in the wild – which is not self-evident for animals derived from captive breeding. They showed typical behaviour and were able to feed on their own. We observed for example several individuals preying successfully on fish and rats. In addition, all European mink which were re-captured showed a good body condition.Up to now, the release of pregnant females and full grown cubs would seem to be the most successful methods. Also, the use of artificial dens seems successful. Wildlife cameras demonstrated that the European

minks used these dens for a long time after their release. In addition to the dens, additional shelters are available which are small enough for the mink to escape potential attacks by their main predator, the red fox Vulpes vulpes.This leads us to consider the problems which every re-introduction scheme can expect and have to cope with. Released animals suffer from an increased risk of mortality. Even in wild populations, the European mink is vulnerable to predation. Of our animals, at least 16 were killed by red fox, which we suspect is more a case of ‘competitor-exclusion’ rather than hunting behaviour. To mitigate this predation, we plan to further increase the diversity and number of available shelters on the river banks.Another problem concerns the monitoring, which is essential to check the success of a reintroduction. However, radio-tracking of European mink is usually only successful over relatively short ranges. Only small radio-transmitters can be used and the animals move near to the ground, so contact can be lost easily if a European mink covers long distances. Live-trapping, even in wild populations of European mink, has limited success. This has held true for our project, due to the obvious (and desirable) independence of our released animals. With the use of wildlife cameras and hair-traps we therefore aim to establish a more standardised protocol for monitoring European mink. These methods should provide reliable data while being cost-effective and enabling the integration of volunteers into long-term monitoring. Other monitoring projects of small carnivores could benefit from the development of a standardised protocol.

Mammal Research

A handful of hope: Three week old cubs born within the EEP captive breeding program. Photo by Florian Moellers

After giving birth to its litter in the wild, a female European mink leads its cubs to one of their first excursions. Photo by Wildkamera Cuddleback® Capture

A European mink inspects a hair-trap at a monitoring site (with additional wildlife camera and cage-trap. Photo by Wildkamera Cuddleback® Capture

By building lodges and retaining streams beavers improve habitats for European mink. Photo by Florian Moellers

The red fox is the main predator for European minks is our project area. Photo by Wildkamera Cuddleback® Capture


Consultants’ page

Henry Andrews MSc MIEEM [email protected]

As an ecological consultant I spend the greater part of my working life in pretty ho-hum habitat with just enough time to identify and describe the interest, such as it is, as I race from site to site staying just far enough ahead of the weather to achieve each objective.I’m a botanist by choice but, in order that my family eat regularly, I have year by year found myself segueing into the world of protected species survey and more and more into the shadowy black-art of bat survey, even learning how to climb trees as a result.In the course of my bat surveys I have climbed several hundred trees to inspect potential bat roost features but, as I inspect the greater percentage of the trees as part of bat surveys to inform planning applications, I often don’t get to return to them and make repeated inspections in order to further investigate my suspicions. Instead, I have to make an assessment of which species might use the feature, and for what purpose, based on the habitat, form of the feature, its location on the tree, and the internal characteristics.In order to do this, in addition to my own experience, I have built up a bank of reference material from which I draw. As the number of variables involved is high these assessments are time-consuming, particularly as information is distributed widely in journals and books. There is also the added complication that even individual species accounts in the same publication may be written by different authors, and differ in format and layout between species. I had begun thinking about assessment criteria for unoccupied potential tree roost features several years ago, but in the winter of 2009 I found myself with a desperate need for something to occupy my mind. So I began compiling all that was known about the tree roost preferences of the UK’s bats into a series of species accounts with the same layout and format. This also highlighted what was not known, a valuable exercise in itself.It’s clear that our tree roosting bat species are nomadic and may use different tree roosts for different purposes at different times. I therefore concluded that for the assessment criteria to be readily applicable it would be sensible to focus on the attributes of the tree and

Who lives in a tree like this?

Through The Tree-Hole

Input needed to a provisional key to bat roost features in trees

A pedunculate oak which holds three brown long-eared bat roosts in different branches. Photo by Henry Andrews at Woodlands Hill, Somerset.

Henry Andrews inspecting a noctule roost. Photo by Tom Staton at Povington Ranges, Dorset.


Consultants’ page

potential roost feature (which don’t move and are visible) rather than the bats (which do move and are, more or less, invisible). We botanists use dichotomous keys as our primary reference material, so I began toying with the idea of a dichotomous key that would enable a simple set of Potential Roost Feature (PRF) attributes to be processed in order to achieve a robust conclusion about the likelihood of a bat roost being present, and the bat species most likely to occupy it.

Having defined what I concluded were the six principal roost types, I worked through the structure of the tree and out into the habitat, losing over a year of my life and driving everyone else who crossed my path mad with my constant wittering. But finally the key was finished.Or was it..?As I mentioned earlier, there are gaps in my knowledge and in published accounts. As a result, many couplets lead to dead-ends for which I have no data. I am sure that

many atypical forms have escaped my own experiences and published accounts and, finally, the key needs rigorous testing. This article is therefore a long-winded call for help from Mammal Society members. You represent a huge resource of experience I wish to tap. So, if you’re interested in bats, or trees, or both, I’ve put the key and some rather more detailed instructions than I had originally envisaged, on the company website. Just go to www.aecol.co.uk, look in the top right corner for the ‘downloads’

tab, hit that, read the four or five lines of blurb and the two PDF are available below. I trust you will note that the key is not for my own financial gain, and is free to anyone who wants a copy.The idea is to collect all the comments and corrections over the next year, update as necessary in the autumn of 2012, and re-release a revised version in the winter for anyone who wants it. I’m not leaving it all up to you, however, but am also enlarging the instructions to include everything I can find out about which trees are most likely to develop which roost features, where (on the tree and in which habitat), and how long they

can be expected to last.It is my earnest hope that by compiling all this information in one location, and providing it free of charge, it will encourage foresters and tree-surgeons to look more closely for themselves, assist inexperienced junior field-surveyors in their training, give a little nudge to PhD students as to which areas might be worth exploring (particularly if they disagree with any of the conclusions!), entertain naturalists during those boring

winter months (it’s a great way to entertain the kids on a winter walk; jelly-baby for each PRF found) but, most importantly, I hope it will result in the identification of a lot of new tree roosts in order that they are safeguarded for the benefit of the bats themselves.So please, if you can fill in any of the gaps, if you find the key mechanics have a fault, if you have found a bat roost in a tree that doesn’t tie in with the relevant conclusion in the key, or if you have found a bat roost of a form that simply isn’t considered, then do let me know ([email protected]). All contributions will be appropriately credited and acknowledged (I’ve had lots of fantastic information from Scotland, some superb information from London, but it would be great to hear of the sessile oak woods of Wales and the beeches of Ireland). And yes it will always be free.I am confident there is a huge volume of experience out there that never makes it to print. Most naturalists only encounter tree roosts very rarely. As a result their existence only gets as far as the dining-room table over the Sunday roast, or a consultancy report that receives limited distribution or (and I was guilty of this one myself) lost as a pencil note in a notebook where the principal subject matter is not bat-related.Finally, I’m confident that tree roosts are not half so hard to find as people think. Certainly, the more I find, the luckier I seem to get at finding them…Happy-hunting!

A Barbastelle in a frost-crack in a sessile oak. Photo by Henry Andrews at Ladies Combe, Somerset.

Natterer’s bat in a frost-crack. Photo by Henry Andrews at Five Lords, Somerset.

A Natterer’s bat in a rot-hollow. Photo by Henry Andrews at Ladies Combe, Somerset.

Barbastelle roost in sessile oak (bat pictured in Pic 4). Photo by Henry Andrews at Ladies Combe, Somerset.

A Noctule in a rot-hollow. Photo by Henry Andrews at Five Lords, Somerset.

A Noctule in a frost-crack. Photo by Henry Andrews at Five Lords, Somerset.

Low-level noctule hibernation roost in dead sessile oak. Photo by Henry Andrews at Five Lords, Somerset.

Mammal News Summer 2012 • www.mammal.org.ukMammal News Summer 2012 • www.mammal.org.uk24

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