people’s trust for endangered The Dormouse species WINTER Monitor 2017/ 2018

Returning dormice to woods in Warwickshire Ruth Moffat & Debbie Wright report on their status in the county, and an exciting reintroduction project.

Investigating diseases From black to gold Do Buy your 2018 dormouse Inez Januszczak explains black hazel dormice have calendar today. Fantastic how she and her team black offspring? Can black photos of the four dormouse check the health of hazel dormice moult their black species found on the dormice before they are and become gold? Gerhard continent: hazel, forest, released into the wild. Augustin investigates. garden and glis. 03 South Brent Wood Fair, Devon

Investigating health and diseases 04 in hazel dormice, at Zoological Society of London

Food for thought: my views from 06 the woods of Dartmoor 15 07 Securing a future for 08 Warwickshire’s dormice

International Dormouse 11 Conference, Belgium In this issue From black to gold: breeding black 12 dormice 04 13 13 2018 dormouse calendar

14 The much anticipated return of dormice to Warwickshire

17 Faulty dormouse nest boxes create death traps, Germany

18 A season of monitoring dormice in nest tubes, Essex

Welcome Over the past couple of years we have commissioned and funded several projects Editorial team: Nida Al-Fulaij, Susan Sharafi, Zoe Roden looking at different aspects of hazel dormouse Illustrations: Hayley Cove ecology and conservation. We hope to better Cover image: Kerstin Hinze understand how and where they hibernate. The opinions expressed in this Investigations have been underway, looking magazine are not necessarily those of into what types of woodland they do best in, People’s Trust for Endangered Species. and how mangement impacts on their Contact us numbers. And results from footprint tracking trials are ready to be analsyed. This year we The Dormouse Monitor should be in a position to share the results of some of these studies with you, and really begin to 3 Cloisters House understand why dormice are still declining and what we can do to halt that decline. With this 8 Battersea Park Road London SW8 4BG knowledge and your help, we hope to begin to reverse the fortunes of hazel dormice in the UK. www.ptes.org [email protected] people’s We hope you enjoy reading all the articles here - do feed back and let us know! 020 7498 4533 trust for facebook.com/ptes.org endangered Nida Al-Fulaij & Susan Sharafi twitter.com/PTES species

2 The Dormouse Monitor South Brent Wood Fair Tom Maddock reports on the Sustainable South Brent wood fair 2017, where he promoted the work of the Hurrells and PTES in conserving hazel dormice.

South Brent is a thriving Devon village on Trees, which has an office and tree nursery chance to grab a coffee in the cafe. the southern edge of Dartmoor, between in Brent, also had a stand. They plant native H.G. Hurrell, MBE, was a founder Exeter and Plymouth. Sustainable South trees on Dartmoor and in the South Hams member of both DWT and the Woodland Brent (SSB) was set up in 2006 by a group of using seed collected locally. Since 2001 their Trust. Without his pioneering efforts our enthusiastic locals, all actively involved in volunteers have planted 60,000 trees in 66 knowledge of hazel dormice would be woodwork, wood-related skills, crafts, local hectares. That’s the equivalent of 110 considerably limited in comparison to our produce, stories, traditions and the rich football pitches. A fantastic amount of knowledge today. His legacy was very much heritage of trees, woods and hedges. This habitat for dormice. felt at the wood fair. Without Hurrell it year the Wood Group of SSB, co-ordinated My display told a very local story of the would have been a very different day. by Robin Toogood, organised a wood fair, at Hurrell family’s pioneering work with the local village hall. dormice around their home, within sight of I only heard about the fair three weeks this very hall, in the 1960s. This included before it was due to occur. I applied for a H.G. Hurrell’s discovery of the diagnostic space, but they were full. There were 30 appearance of a dormouse-opened hazel stalls, including the Forestry Commission, nut; his daughter Elaine’s use of this Devon Rural Skills Trust and Dartmoor discovery to investigate the UK distribution National Park Authority, and a full of dormice, and their early design for a programme of events, including walks, talks, dormouse nest box. Elaine subsequently storytelling and music throughout the day. wrote two further monographs about the The best offer I had was to share space with hazel dormouse. Devon Wildlife Trust (DWT). One of my nest I gave out numerous dormouse-opened box sites is at the DWT Reserve, Andrew’s nuts and explained the current work of Wood, downstream from Brent, so I was in NDMP. The State of Britain’s Dormice 2016, with a chance. I arrived early. One stall away produced by PTES, proved invaluable. And from the DWT stand, next to local company several people took photographs of the One joiner, One Engineer, was the Woodland PTES display material. People had come Trust table. Their display had not arrived, so from all over the county, and beyond. It was I acquired their table - a prime site in the non-stop from 10am until close at 5pm. I was main hall. Thank you Woodland Trust! Moor grateful to Celia Ralph of Brent DWT for a Tom Maddock

The Dormouse Monitor 3 Investigating diseases in hazel dormice Inez Januszczak, Pathology Technician for the Disease Risk Analysis and Health Surveillance programme (DRAHS ), Zoological Society of London, details how post mortems help us learn more about the health of dormice.

Zoological Society London For over 20 years, PTES has led reintroductions are being used to bolster Trusts. Over time, the aim is for a self- reintroductions of hazel dormice - an populations. The Zoological Society of sustaining free-living wild population, incredibly charismatic species that some London and Natural England have been which longer requires human intervention. say represents the British countryside. It has supporting those reintroductions through The process of a dormouse been in decline probably in part due to the health and disease monitoring for the last reintroduction includes breeding them in fragmentation of woodland and the 18 years, with assistance from Paignton Zoo captive collections after which they are decrease in hedgerows, thus and Environmental Park and the Wildlife quarantined for up to three months. This quarantine period is crucial to ensure the dormice are as healthy as possible at the time of release and to try to ensure that they can be released into the wild free from any non-native diseases that could impact wild populations. During quarantine, the dormice are microchipped which means any dormouse found after the release can be identified. Similarly, if non-chipped dormice are found, this indicates that the reintroduced dormouse have produced viable offspring. However, where there is life there is also death – and on occasion dead dormice are found. But this presents a unique opportunity to investigate the threats to dormice present today. The Disease Risk Analysis and Health Surveillance programme (DRAHS), based at the Zoological Society of London, and a partnership with Natural England, with support from PTES, carries out post- mortem examinations of dormouse carcasses found at reintroduction sites and also elsewhere in the countryside – a kind of ‘CSI’ for rodents. DRAHS works with a network of volunteers across the country that submit dormouse carcasses for post mortem examination – and they are accepted in any condition, whether they are freshly dead or mummified. We can collect valuable information on fur quality, bone and skeletal health even from mummified carcasses which increases our understanding of their health. There are numerous reasons why a dormouse could die in the wild – from bacterial sepsis to acute respiratory failure. At DRAHS the aim is to have a record glass slides of organs can be taken to look of diseases found, which is achieved at any microorganisms that could be through a detailed post mortem present – organisms that are too small to examination protocol involving not only be spotted with the naked eye. Pieces of DRAHS is always interested in receiving external examinations but inspection and organs can also be sent for histological dormouse carcasses so that we can sampling of organs (to search for viral, analysis – where the tissue can be examined continue our monitoring work. Please bacterial, fungal, and other parasites) and more closely. This can give us a better idea contact [email protected] if you would like to Zoological Society of London measuring of body parts. of the state of the organs at the time of know more about submitting dormouse These investigations increase our death, and can further determine whether carcasses to be examined post mortem. understanding of the threats to dormice, and there were any signs of disease. when assessed in the context of the Parasites such as nematodes might be population dynamics in the woodland of found within the internal organs, especially concern, can give us a potentially valuable insight into the viability of both reintroduced and other populations of dormice. These The first step of a post- insights can then aid future reintroductions, as well as acting as a map of potential mortem is to look closely diseases which can point to improving for any abnormalities on reintroduction methods in the future. It’s important to approach post-mortem the external body examination in a methodical way using the same sequence of inspections to ensure nothing is missed. The first step of a post in the digestive tract. Although a certain mortem examination is to look at the number of parasites may be acceptable, a external body and look closely for any large burden of parasites can cause disease. abnormalities. If the potential contributor What the appropriate number is would not of death was a physical one, such as a head only depend on the animal but the type of collision or predation, this may be visible in parasite itself. the first stages of the examination. Finally all parts of the body are saved, in Sometimes detritivores are also found on either formalin or a -80 freezer archive to the carcass; these can range from maggots ensure we can gain the most from further to beetles, which can also act as a guide to tests, future advanced tests or evaluate any how long the dormouse has been dead if diseases in the future when new other factors such as location of finding and information becomes available. ambient temperature are taken into Over 120 dormice have been examined account. post mortem by DRAHS. Important findings The next stage is to remove the skin and have included respiratory and eye disease. look at the internal organs. The inside of the One dormouse was found with severe eye skin is noted (any internal bruising disease which was shown to be associated becomes more evident at this stage) as well with nematode worms. By finding out the as the amount of sub-cutaneous fat seen life cycle of these worms we were able to around the organs. The levels of sub- show that a damp environment in a nestbox cutaneous fat as well as the elasticity of the had enabled the worms to make contact skin is seen is an important measure of how with the dormouse. Consequently, we have healthy the dormouse was at the time of been able to advise nest-box checkers of the death, as any signs of starvation or importance of removing damp material dehydration would become apparent at this during routine nest-box checks point. DRAHS enters the information from The organs are then carefully removed every examination into a database, and and looked at individually. The heart, lungs, holds an archive of all carcasses. Together digestive tract (including stomach and these represent a valuable resource for spleen), liver, kidneys and sexual organs are further investigation of dormouse health, all dissected and analysed, sometimes even which means if more information on the under a microscope. Depending on the health of a certain population is required freshness of the carcass, this can be harder the archive can be referred to at any time. It to do – each organ has a particular colour is through this kind of monitoring that we and texture it maintains after death, and the are able to try to ensure the reintroductions more decomposed the carcass the harder it taking place are successful for the is to pick up on any irregularities. However, reintroduced animals themselves and the current analytic methods mean swabs or surviving population.

The Dormouse Monitor 5 Food for thought: my view from the woods of Dartmoor Matt Parkins, who lives and works on Dartmoor, shares his thoughts about what makes the woods such a special place.

I feel right at home in the woods. For me, the with various insects flitting about, and with coloured fur and deep, dark eyes squinting protective canopy of trees provides the worms crawling through the damp earth, up at me each time have created a bond perfect shelter with endless opportunities and to reflect that these elaborately between us. Not only am I on their side, to for my inquisitive mind to go exploring. constructed forms, so different from each stand up for them, I am in complete Many times, I have considered building a other, and dependent upon each other in so admiration of them. We humans regularly log cabin and moving in. As John Muir, the complex a manner, have all been produced disturb their habitat, causing their numbers 19th century conservationist said, “I only by laws acting around us.” to fall and, in some counties, to disappear went out for a walk and finally concluded to One of these woodland characters is the altogether. They show adaptability, stay out till sundown, for going out, I found, dormouse and, for several years, I have been resilience and a great will to survive and, in was really going in.” I take every chance I can fortunate enough to get up close to this Devon the diversity of connected wild flora to immerse myself in the woods, absorbing endearing creature. Being licensed to and food sources has allowed them to hang the atmosphere, studying the scenes and monitor the little hibernator is always an on. They are often described as an indicator describing the detail. adventure and each time a nest box is of a good habitat but they are more than Nothing in the woods can be seen in examined it’s like opening up a miniature that, they are torch bearers, flag wavers for isolation. Each and every living thing is a woodland world and peering in. Is there a the protection of our precious woodlands. part of the big picture. Each tree, flower, bug dormouse in there, or a wood mouse? Bees, Scanning the woodland floor for the and bird performs its role in the spectacular wasps or hornets? Are there birds nesting in remains of hazelnut shells you can get an Mattt Parkins stage-show of life. Charles Darwin observed there? Blue tits or wrens? Or is it one of the idea of which species has been responsible “It is interesting to contemplate a tangled usual suspects; millipedes, woodlice or for eating the nuts. While nut shells with the bank, clothed with many plants of many slugs? If it is a dormouse, the thrill of trademark neat, smooth hole made by the kinds, with birds singing on the bushes, discovery never subsides. The honey dormouse can be found beneath the hazel shrubs in Dartmoor’s woods, the majority, in themselves in the woods of mainland UK, to the mainland woods. Undisturbed fresh no uncertain terms, have been opened by but there is a long way to go. growth of broadleaved species was the more powerful jaws of the grey squirrel, If this work continues I am hopeful that, everywhere, hazelnuts were abundant and and a series of national Great Nut Hunts in time, we can see the results; perhaps bark stripping was virtually non-existent. have confirmed this. Among the many greater quantities of food available for This was not a scientific study but I thoughts and theories rolling round in my dormice and less damage to trees from bark wonder whether the Dartmoor woods could head, I am constantly questioning whether stripping – a regular accusation made of the be more like this. Woodlands that are more the introduced grey squirrel is out- greys. in balance in this way feel right; more like competing the dormouse for both food and Worrying levels of damage to Darwin’s tangled bank of interdependent habitat. While there are many other climatic broadleaved tree growth and regeneration species in action. As a bit-part player in and human influences that have a negative isn’t entirely the preserve of grey squirrels. It some of the most exciting woodland effect on dormice, I feel the greys have got a is widely reported that, in the absence of regeneration projects around Dartmoor, I lot to answer for. After they were brought to natural predators, the UK mainland will continue to champion the cause for the the UK, the expansion of their range and the population of deer is at such a high level, the red squirrel. Over the coming decades, the spread of the squirrel pox virus they pressure they put on the recovery of large woodlands along the Teign and Bovey brought with them has decimated our woodlands is immense. On a recent trip to river valleys are likely to provide the perfect native red squirrel population. The reds the Isle of Wight I took a walk in a few of the habitat for them; habitats on a landscape have been driven out to a few distant woods there. The island is a haven for red scale with a healthy mix of conifer and strongholds including the Isle of Wight and squirrels and the deer numbers are very low. broadleaved trees. In reality, it’s not going to some of Scotland’s forests. Cut off from the mainland, the island be just as simple as that, though. As Though many people have never seen habitats show what the UK’s woods could be demonstrated by projects across the one, a few red squirrels are still around and like if there were red squirrels without greys country, volunteers need to put in many volunteers and conservation groups are and if deer lived at sustainable levels. The hours of coordinated effort and trapping making a huge effort with various captive first striking difference hit me where the greys will probably make the fur fly, but breeding and reintroduction projects. One People’s Trust for Endangered Species is everything is possible. With the wide-open of the most successful of these has managing a private woodland at spaces of Dartmoor to the west and Devon’s eradicated grey squirrels from Anglesey Briddlesford. Hazel coppicing work is done coast to the east there are ready-made grey where today, the red squirrel population is there without the threat of heavy deer squirrel barriers already in place so, who doing well across the island. browsing. The new shoots require no knows? In time, with willing and committed Between Cumbria and Cornwall, red protection and eagerly grow to form a lush conservation groups, we could create that squirrel conservation and grey squirrel understorey below the oak canopy; perfect tangled bank, clothed with plants, with control projects are showing some good for dormice. Consequently, there is a high birds singing, insects flitting about, worms results. The habitat strongholds around the population in this wood and they exist crawling through the earth and dormice country are being protected while the range happily, side-by-side with the red squirrels. living cheek-to-furry cheek with red of the reds is, very cautiously being Walking in other publicly accessible squirrels in the arboreal world above our expanded. Constant monitoring continues; woods on the island, the woodland heads. checking that the reds can establish character continued to show the differences Matt Parkins

The Dormouse Monitor 7 Securing a future for Warwickshire’s dormice Ruth Moffat, Dormouse Conservation Warwickshire, reports on the dormouse work that has been carried out throughout the county over the past few years. The release of 38 dormice into ancient woodland in Warwickshire on June 20th 2017 was the fourth attempt to bring back a much loved animal to the heart of England. Years of surveys and monitoring, and several earlier releases spanning more than two decades – including the first release of wild dormice, at Bubbenhall Wood, in 1998 – have gone into trying to repopulate the Midlands with this charismatic, squirrel-like rodent, sadly better known in literature than in the wild. In Shakespeare’s Twelfth Night, the dormouse is an adjective: ‘Awake your dormouse valour’, says Fabian, meaning sleepy, dozing or slumbering. In Alice in Wonderland, a sleeping dormouse is used as a cushion by the March Hare and the Mad Hatter when Alice arrives at the tea table. This lazy, slightly hopeless depiction seems to have made the attractive little animal a popular pet; in the late 19th century the species was common, indeed it was known in almost every English and Welsh county. The dormouse is distinguished from other mice by its furry tail and its habit of sleeping through the winter – strictly speaking, it hibernates. The name perhaps comes from the French dormir, meaning to sleep, or the Middle English dormous, location now in the centre of the town. monitoring, a more efficient technique than meaning sleepy. Regional names reflect this There is a record from 1885 of a stuffed nut searches, was established by the sleepiness: dory mouse, derry mouse, specimen caught at Edge Hill, near Forestry Commission. Records were erratic dozing mouse, sleep-mouse, sleeper and Stratford-on-Avon, and another of similar for a time, with a productive year in 2009 seven-sleeper. In the north of England the date of a live animal from Yardley Wood, when 25 nests were found – including nine name ‘dozy mouse’ may come from the Old now part of Birmingham. The 1904 Victoria animals in one month. Sadly, dormice were Norse dusa, and in Devon the species County History for Warwickshire is last recorded there in 2013, but the decline acquired the curious name of ‘chestlecrumb’. equivocal: ‘The dormouse has been said to may be just a natural dip; the number of In 1993 the Great Nut Hunt, organised by occur in the county though the writer has nest boxes has since been doubled in order Royal Holloway College, London, to find and not met with it.’ Between 1999 and 2000, to see if the population has moved within identify hazelnuts eaten by dormice, English Nature conducted a survey of the wood. Weston Wood and neighbouring suggested that in the hundred or so years dormice in Warwickshire, in recognition that Waverley Wood, managed by the since Alice’s trip to Wonderland this once the county was at the northern edge of the Commission as one unit (the latter was also common mouse had disappeared from animal’s contemporary range and it was not included in the English Nature survey), about half of its former range, and was now known from only a few sites. The survey, remain the only place with a confirmed concentrated in southern England and which covered 27 woods and relied on natural population in Warwickshire. Our Wales. searching for nuts eaten by dormice, found only other known dormouse population is at Warwickshire is one of a band of six evidence of the animal in only five places. Windmill Naps, the only successful Midland counties from Staffordshire to In 1991, a hibernating dormouse had introduction in the county so far, which Hertfordshire where dormice are now rare. been found at Weston Wood (not included seems to thrive; since 2009, annual counts of Records began in 1871 with the report of a in the English Nature survey), close to individuals have built up to 82 captures in single dormouse in the Rugby area, at a Bubbenhall Wood, after which nest-box 2016, although numbers recorded may

8 The Dormouse Monitor important habitat for dormice was - the site has past records of dormice deciduous woodland with scrub, hedgerows although surveys by the WDCG in 2012-13 and old coppice; at the time, 30–50% of indicated a current absence; a second semi-natural woodland and 140,000 miles of release into an adjacent wood is planned for hedgerows had been lost from Britain since 2018. Both woods have good dormouse the 1940s, while coppiced woodland was habitat and fit the recommendations for largely a thing of the past. The decline was suitability, being more than 20ha in area thought to have been due also to and having appropriate management. The inappropriate management of the Natural England requisite that remaining hedgerows and a changing reintroduction sites should be in clusters to climate, the latter resulting in cooler mean create viable meta-populations, rather than temperatures and higher rainfall in the one large woodland, is also met by these summer when dormice are active . Climate and other woods in the area. Dormice thrive change can also disrupt the hibernation in low-growing woodland, with a diversity cycle, causing dormice to wake too often in of tree species, and with continuous warmer winters and use up fat reserves, above-ground routes which these arboreal while they can be short of food in cooler animals can use. The long-rotation hazel- summers, when there are fewer insects, coppicing that is taking place here should fruits and flowers. These food sources are a create more than 150ha of dormouse- vital part of their diet early in the year, friendly habitat, all well connected by good Map of woodland over 20ha in size in before berries and nuts become available. quality hedgerows. Over the next two years Warwick, Coventry and Solihull. The presence of hazel, however, seems not Dormouse Conservation Warwickshire to be essential, as evidenced by a (DCW) and the Warwickshire Mammal include repetition since dormice can be very population at Ribbesford Wood, in Group (WMG) will help to establish these mobile and found in more than one box Worcestershire, a conifer plantation that new populations by feeding the newly during the checking season, hence the term apparently provides good habitat. In such released animals and checking nest boxes ‘captures’. woods, dormouse food is likely to consist of for survival and breeding. For many The loss of coppiced woodland and aphids, caterpillars and pollen, all members, this will provide their first sight of hedgerows, and the fragmentation and containing high levels of calories, while a dormouse. deterioration of remaining woods and nests have been found in deciduous Since 2009 DCW (then known as the hedges, contributed to the dormouse’s woodland, made entirely of pine needles, Warwickshire Dormouse Conservation decline, with the rate at which suitable instead of the usual honeysuckle bark and Group) has carried out surveys with nut habitat was being destroyed a very fresh leaves. hunts, nest tubes and nest boxes in 16 significant factor. A Mammal Society survey This latest release is a true woodlands but has so far drawn a blank. in the 1970s showed that the most reintroduction, rather than an introduction However, we remain hopeful ... a map of records for dormice since 1871, admittedly suitable size; 20ha is considered the critical some unconfirmed, (Chris Talbot, HBA, size for the sustainable survival of a Warwickshire), shows that they come from dormouse population by Bright et al. 2006 all corners of the county indicating that at (The Dormouse Conservation Handbook). one time the species existed throughout Members of DCW and the WMG will Warwickshire. Including anecdotal records, continue the search in other potentially these add up to 23 sites where we either ‘dormouse-friendly’ areas of the county. The know that dormice exist or there is evidence second map shows all areas of woodland of that they may still exist. 20ha and over, many of which are Looking for evidence of dormice along agglomerations of very small woods and the proposed HS2 route through wooded strips along roads and canals, and Warwickshire by consultants for Arup and others have already been checked for Adkins between 2012- 14 was no more dormice. It is clear, however, that there are successful. Potential dormouse habitat six clusters of woodland (marked red) that within 100m of the line was identified by could be investigated, for which we have no aerial photography, followed by site visits to records or only very old ones. assess their suitability for supporting a population. No dormice, or evidence of their This article contains edited extracts from presence, was found despite nut searches ‘Much Ado about Something - and the installation of a total of 2755 nest securing a future for Warwickshire’s tubes and 135 boxes at 24 sites over two Dormice’ which appeared in the years. These were left for only one season, August issue of British Wildlife 2017, vol.28, not the best way of surveying for dormice, no.6: p.399-404. as they can often take a season to find them; however, they have been known to build a A 45-page report of the search for nest in a tube within two weeks of its Warwickshire’s dormice since 2009 installation. This survey effort was vastly in ‘The status of the Hazel Dormouse Above: Warwickshire dormouse excess of that of DCW and yet no dormice (Muscardinus avellanarius) in records. were found, possibly explained by the fact Warwickshire, Coventry & Solihull in 2016’ that only three of the woods were of a - can be viewed on the PTES website. Below: a traditionally layered hedge. International Dormouse Conference, Belgium September 2017 was the occassion of the tenth International Dormouse Conference, in Liege Belgium. Nida Al Fulaij, PTES, attended as part of the UK contingency.

Every three years, dormouse dormouse species from around the home to both hazel and garden researchers, conservationists and world. dormice. The landscape was a variety enthusiasts from around the world Talks were given on camera- of farmland, woodland and railway gather to share ideas, stories and results trapping, modelling work, the use of verges. A fantastic landscape home to from current research. The conference footprint tunnels, detailed genetic high densities of hazel dormice. We took place over five days in Belgium, analyses, and feeding studies. Results had a chance to look for natural nests Liege. Organised by Alice Mouton and were presented from work in many amongst great swathes of clematis. It Goedele Verbeylen, the conference countries including Germany, Belgium, was surprising how many wild nests we focused on research and conservation Japan, Bulgaria, UK, Russia, France. found along the roadside, and just how methods for five different European The first evening, the delegates were difficult they were to spot. dormouse species, as well as other welcomed with an introductory dinner We will report in more detail about at the University of many of the talks that were given at Liege. The university the conference in future articles, as the then hosted the next research is published. In the meantime, few days of talks, which if anyone is interested in receiving were followed by an a copy of the proceedings please excursion to Voeren. visit the conference website http:// Here we had a chance dormouseconference.net/index.html to walk through varied dormouse habitat,

The Dormouse Monitor 11 From black to gold Gerhard Augustin has been investigating whether black dormice will have black or golden offspring, and if they will moult back to a natural colour.

Black hazel dormice were found in darker than normal coloured hazel dormice Schleswig-Holstein in North Germany in at two years old. The second female is still September 2015. The group consisted of a nearly black. Their brother has moulted and golden coloured mother, with a litter of four retained his golden coloured fur juveniles, approximately four weeks old. The throughout. juveniles, both male, were the colour of The animals were paired up with normal normal hazel dormice. However the other coloured animals from the same region and two, both females, were both black with a bred, to see what colour traits their offspring white patch on their throats. would display. In total 15 young were born The animals were taken into captivity during 2016 and 2017. The first lighter and observed to see what happened to the coloured female gave birth to two litters, colour of their pelage as they developed. one of five and one of four babies. Her sister Would the colour persist or change when had one litter of two young. Their brother they moulted? Was the colour inherited? sired four offspring. None of the young Would they pass the trait on to their produced by any of the siblings were black. offspring? A licence was obtained from the All the offspring were released back to the Nature Conservation Agency and the two site of origin when they became black sisters and one of the golden males independent. were taken into captivity. It appears that the gene for black fur Both black sisters retained their dark fur colouring is recessive. Although the black colouring after two hibernation periods, and offspring remained dark throughout their after moulting. The first female became lives, the did not pass the feature on to their slightly lighter over the years but is still offspring.

12 The Dormouse Monitor 2018 dormouse calendar available to purchase now

The new 2018 dormice calendar is now available. It is high quality print and is available in large format A3 and extra large A2. The price is €19,99 for A3 and €25.00 for A2. Postage is €6, for A3. Please ask about shipping costs for A2. To order a calendar, or for more information, please contact Kerstin Hinze by email on [email protected]

The Dormouse Monitor 13 The much anticipated return of hazel dormice to central Warwickshire Debbie Wright , Warwickshire Wildlife Trust, Warwickshire Mammal Group and Dormouse Conservation Warwickshire, describes the much anticipated release in 2017.

June 20th marked an important day for Woodlands Living Landscape Scheme preparation for the new arrivals. conservation in Warwickshire: Thirty (supported by the Heritage Lottery Members of the Common Dormouse eight dormice were released into an Fund), in which ancient wooded Captive Breeders Group were busy ancient woodland near Leamington landscapes are being restored and looking after the chosen dormice, Spa. The release was the result of years connected across part of Warwickshire. which were quarantined prior to the of hard work and preparation, which Two years prior to the release, 150 release for six weeks at Paignton Zoo eventually came together with the first nest boxes were erected on trees in the and ZSL to conduct health checks and of two planned reintroductions by woodland and monitored for their use reduce any threat of disease. Each PTES, Warwickshire Wildlife Trust and by bird and mammal species. In April dormouse was PIT-tagged, to enable other partners. The reintroductions this year a further 150 nest boxes and 18 identification using a portable reader in form part of the Princethorpe large mesh release cages were put up in the field. When the big day came, the dormice were placed in pairs or trios into the release cages, with the hope of encouraging breeding. They were provided with food and water in the cages and given time to acclimatise

Ancient wooded landscapes are being restored and connected

themselves with their home. For many, especially dedicated volunteers from Warwickshire Mammal Group and Dormouse Conservation Warwickshire, this was their first sight of the charismatic small mammal that they had longed to see return to the area. The volunteers took part in a feeding rota for the next 10 days. Each day, the dormice were given water in the cages, the amount of food they had eaten was recorded, and a new portion of dried food and fresh fruit was provided. After 10 days, the dormice were checked by a team of licenced and supervised non-licenced staff and volunteers. Boxes from the cages were opened in large plastic bags, and the dormice inside were scanned with a PIT tag reader. Their sex, breeding status, weight and overall condition were then

14 The Dormouse Monitor checked and recorded. The dormice appeared to be in generally good condition. Although some had lost weight since the introduction day, they had been pretty well fed to start with! After being returned to their boxes and cages, a small door was then opened on each cage, enabling the dormice to leave and explore their new woodland surroundings. A remote camera was set up near one of the cages, to see if we could catch a glimpse of any activity. Volunteers continued to feed the dormice but less frequently, initially every two days and then every three days. With less food disappearing from the cages, it was hoped that the dormouse boxes erected in the the nest. If a dormouse was found, it dormice were finding their own natural woodland. On approach, the hole to was placed into a small plastic bag, food source. Some hazelnuts left in the each box was quickly blocked and the before being scanned using the PIT tag cages appeared to have been lids carefully slid to one side to see if reader (if adult) and weighed. Dormice unsuccessfully gnawed on. It is thought anything was inside. If a dormouse or a were aged (using cues such as colour, that the characteristic way that tail furriness, size and whether their dormice open nuts may be shown to eyes were open), sexed, and the young mice by their mothers, and so It was hoped that the breeding condition, status and overall there were concerns that the dormice dormice were finding condition recorded, before being would not know how to eat the nuts, returned to the box. When very young having been captive bred. However, their own food sources dormice were found (pink or grey eyes during the feeding schedule, some closed), they were weighed together open nuts with the tell-tale dormouse nest was visible, the lid was returned and an average weight was recorded. nibble were found. and the box removed from the tree and Dormice were recorded quickly and In early September, Warwickshire placed inside a large plastic bag. Each efficiently so as to minimise any Wildlife Trust staff and a group of corner of the box was then checked for distress, especially when a mother and volunteers went to check all of the signs of warmth or an entrance hole to young were present. Li Williams The results of the box check were reintroduction will also take place in a highly encouraging with 38 live young nearby woodland next year, with the and 11 adult dormice found. An hope of creating viable meta- additional 16 dormouse nests were populations across clusters of suitably found in the boxes. Interestingly, managed habitat. Hazel dormice are despite having being captive bred, often found in long-rotation hazel- many dormice had made nests that coppiced woodland, with diverse tree appeared to be ‘text book’, with a clear and shrub species that provide varied woven structure mixed with deciduous food throughout the year, and a leaves. Eight litters of dormice were continuous 3D structure that suits their found, ranging in age from new borns, arboreal lifestyle. Both reintroduction to those with grey fur and closed eyes, sites have past records of dormice that those slightly larger with open eyes, appeared to go locally extinct and and juveniles. Five adult females were could now comprise more than 150ha of found in the boxes along with litters, connected dormouse-friendly habitat. three of these were lactating and two With only two natural populations post-lactating. Two smaller litters known in the county, and one comprising six new borns had died in introduced population, it is hoped that the boxes. The adult dormice appeared these reintroductions will bring back an to be in good overall condition post- expanding population of hazel dormice release. They weighed an average of to central Warwickshire. 19g, which was thought to be sufficient A 45-page report of the search for given the time year, with time still left Warwickshire’s dormice since 2009 ‘The to build up fat reserves before status of the Hazel Dormouse hibernation. There certainly did not (Muscardinus avellanarius) in seem to be a limited food supply, with a Warwickshire, Coventry & Solihull in plethora of ripe blackberries to be 2016’ can be obtained from Ruth Moffatt found throughout the woodland. at [email protected]. Monthly box checks by Warwickshire Mammal Group in the future will follow the progress of these dormice and their young. A second Faulty dormouse nest boxes create death traps, Germany Sven Büchner & Johannes Lang, Institute for Animal Ecology and Nature Education, Germany, tell a tragic tale about faulty nest boxes.

There are different methods available to received in each situation suggest that detect evidence of hazel dormice. One all the animals died in identical of them is monitoring using wooden circumstances. The empty nest boxes nest boxes, either built for birds or contained dormice in different states of specially designed for dormice. decay. The animals had no or marginal Translocating animals out of an area to nest building material in the boxes with be developed, into other appropriate them. The inner walls always featured habitat is a suitable conservation obvious gnaw marks, clearly indicating measure to avoid the loss of hazel that the dormice had been unable to dormice. In many cases, nest boxes are leave the box after they first entered it. used for this purpose too. The animals There is one plausible explanation: can easily be trapped in these boxes All the nest boxes were, contrary to the and they help to facilitate the animals’ common design, built from flat-planed establishment in the resettlement area shelves. To the best of our knowledge, since they will have built their nests in only the bottom and the lower parts of the boxes and have somewhere familiar the side panels were gnawed– up to a and safe. level that the dormice were able to Last year, reports about three major reach from the bottom of the box. This transactions in two federal states indicates that the planed shelves were Luckily we’ve been able to identify reached us, concerning dead hazel too unruffled for the dormice to climb one producer of these boxes to point dormice in nest boxes. Since we have back the walls to the exit hole. To prove out the construction fault. The boxes substantial experience using nest that this is what had happened, we that they have already produced will boxes for establishing, monitoring and simulated the situation with four hazel now be roughened on the inside so that resettling hazel dormouse populations, dormice (two male and female each) any animal using it will be able to climb we were asked to estimate plausible using a nest box of the same design. easily up the sides. causes of death. Only the biggest male succeeded in Unfortunately, the cases were not reaching the height of the entrance documented sufficiently which makes hole by clambering up the side. The determining the root cause almost remaining three animals failed and slid impossible. Yet the descriptions we down the smooth inner wall.

17 The Dormouse Monitor A season of monitoring dormice in nest tubes Michelle Tyrrell reports on research she carried out at Norsey Woods in Essex dring 2016, looking at how hazel dormice used nest tubes and the types of nests they built.

Nest tubes are one of the easiest and most During the active season, dormice build photographs taken of any nests present. common tools we can use to determine if grapefruit sized nests with an entrance hole Between April to December 2016 a total hazel dormice are present in an area. Paul on one side, either in dense vegetation, tree of 19 nests were recorded in the 50 tubes. Of Chanin and Michael Woods calculated the crevices, nest tubes or nest boxes. Individual these, nine were selected from eight tubes level of survey effort needed to find dormice animals are known to have multiple nests at for displaying interesting insights into in any given month or season, based on a any one time. The nests built by dormice dormouse behaviour and nesting activity. study they carried out in south-west can vary quite substantially. They can be A layered maternity nest was recorded England. In 2016 the Essex and Suffolk classified into different types. Mixed nests in tube 9 in September. It contained three Dormouse Group replicated this study consist of woven leaves of trees or shrubs, young pink dormice, less than a week old across 20 sites to investigate nesting interspersed with grasses. Layered nests and their mother. The female initially patterns in the East of England. Michelle have two distinct layers: an outer layer of escaped but was soon captured and Turrell and Kate Mann put up nest tubes in tree or shrub leaves, and a woven inner layer successfully returned to the tube. Dormice Norsey Wood SSSI/LNR in South Essex. Nest of finer, softer materials. Grassy nests consist were not recorded in the tube for the rest of tubes were installed at 15-20m intervals and of a dense sphere of dry leaves of grasses the year so it is highly likely that she moved photographs were taken monthly of all and are more prevalent in coniferous her young to a nest nearby. There were no nests that were found. woodlands. Foliar nests are plaited from dry changes to the nest in October but it had The results were valuable in revealing or fresh tree or shrub leaves, with some been maintained in November and dormouse nesting activities throughout a supplementary grasses. remained in the same state in December. season. Surveys early in the year are Fifty nest tubes were installed in March An unstructured nest comprising considered to be unreliable so it is 2016 in a copse of Norsey Wood. The 70ha mainly dry leaves and a little shredded recommended that surveys are undertaken woodland is an NDMP site which contains material was recorded in October in tube 10. regularly, monthly if possible. If there are 100 nest boxes. The tubes were installed at Inside was an 11g juvenile dormouse. small populations of dormice in an area it is 15-20m intervals on suitable horizontal Surprisingly in November the nesting possible that their presence might only be vegetation. The copse was chosen as material had been entirely removed. detected late in the year. Therefore, it suitable habitat because it has a good A nest with a distinctive inner and outer recommended that surveys are carried out three-dimensional habitat structure, layer was recorded in tube 11 in August, throughout the full active season to be as comprising hornbeam, bramble and inside which was a 17g female dormouse. certain as possible whether dormice are honeysuckle. The tubes were checked each The nest was maintained and still in good present or not. month from April to December and condition by September but had been

Tube 10, October. Dry leaves, shredded A 17g female dormouse was found in a The same nest in tube 11 was still being used material and a juvenile dormouse. distinctively layered and woven nest in tube a month later. It had been well maintained 11, in August. and kept its shape.

18 The Dormouse Monitor Tube 11 still contained a dry nest in October By November the nest in tube 11 was This nest was still being used by a male and a 19g female dormouse was found in the still present and had been enlarged. The dormouse in November, although the nest nest. impression of a small mammal was visible. was becoming wetter, damaged by October, though a 19g female July a woven nest had replaced the previous remains of the nesting material were still dormouse was using it. By November the materials. In August the nest had become there in June. But by November a new nest nest had been enlarged and had a small unstructured. However, a lactating female of dry leaves has been constructed and the mammal impression in it. This was no 17g dormouse was recorded with five grey nest contained a 20g male dormouse. In longer visible by December when the nest babies (6 - 20 days old) in September. In December the nest had been reduced to a had less structure/material. October a 20g female and 11g male cluster of leaves, lacking structure. Inside tube 12 was a layered nest dormouse were recorded in the slightly In total five of the nests were layered, comprising dry leaves with a woven more maintained nest, which remained in a one created from foliage and three classified chamber in November. However, the tube similar state but empty in November and as unknown because they were incomplete. was particularly wet by December and December. The majority of nests were layered, mainly interestingly lacked most leaves. The A potential nest was recorded in with dry leaves. Current best practice beginnings of a woven nest with fresh September in tube 26, comprising both guidance describes dormouse nests as leaves was recorded in October in tube 21. fresh, dry leaves. However, in October the being commonly made with fresh, green The nest was being used by an 11g juvenile tube was empty. leaves taken directly from the trees. But this male dormouse. By November, the nest was A male and female dormouse were was not the case for a large number of nests completed and being used by a 21.5g male recorded in torpor in May lying on an recorded. Furthermore, the nest in tube 38 dormouse. In December the nest contained unstructured nest of dry leaves and fresh in May was atypical for dormice. Dormouse more fresh leaves but was particularly wet. grasses in tube 38. The nest would not be presence would not have been confirmed if The start of a nest was recorded in tube considered to be a dormouse nest if found the dormice themselves had not been 22 in June, comprising fresh, dry leaves. By with no animals present. The sodden present. No other nests or dormice were

This same nest in tube 21 had more fresh The beginnings of a nest were found in June, The same tube, 22, contained a fully woven leaves in December but was incredibly wet. with fresh, dry leaves. nest by July with dry leaves on the outer layer.

The Dormouse Monitor 19 recorded in April or May, suggesting both recorded at the site, recycled the habitat management. Ultimately this surveys early in the active season can be materials. Dormice are known to have indicates that tube surveys could falsely unreliable in determining presence or multiple nests but other small mammal conclude an absence of dormice if absence based on field signs alone. species are also known to have surveying isn’t carried out later in the year. Three potential nests that were unstructured, leaf-dominant nests. Therefore, it recommended that surveys are predominantly made of leaves were Therefore, it is unclear which species would undertaken throughout the full active removed from the nest tubes after one recycle or remove the vegetation. However, season. month. The dormouse recorded in tube 10 it does prove significant when surveying for Four tubes contained nests for long was found with this type of unstructured dormice. Thus, it is recommended that periods: three to six months, requiring nesting material. Both potential nests in tubes are surveyed regularly to increase periodic maintenance. The longest tubes 10 and 26 were removed in chances of recording dormouse field signs, inhabited nest became a maternity nest and September, and no further nests or small in accordance with guidance from Natural as the young grew the nest became mammals were recorded in them for the rest England. unwoven due to the limited space in the of the year. However, the potential nest in A large proportion of nests were built tube. Other nests were also found damaged tube 22 was replaced with a structured between September to November, and or unwoven by the end of the active season woven nest in July which became a many were actively maintained during this which could impact the certainty of dormouse maternity nest. It is unlikely that period. This is unsurprising when dormouse field signs later in the year, if not human interference is the cause of these comparing nesting activity to records of surveyed regularly (depending upon the disappearing nests as the tubes were well dormouse populations in south-east individuals experience). Therefore, regular camouflaged by dense vegetation when England, which are highest later in the year. surveys are recommended both removed. Therefore, it is more likely that However, discovering new nest building in commercially or voluntarily to increase the either dormice or other small mammals, November was surprising, and challenges probability of recording dormice more such as wood mice or yellow-necked mice, best practice guidance for the timing of accurately. Caroline Mc Donald

Tube 22 was still being used by September. By October, tube 22 was still being used but The nest remained in tube 22 in November This time a 17g mother and her litter of five now by a 20g female and an 11g male. and December but no animals were present young were present. on either check.

In May two animals, a male and female, were The following month, June, this was all However by November a fresh dry nest was found in torpor in a very unstructured nest. that remained of the leaves that the torpid found in tube 38, containing a 20g male. animals had been found in during May.

20 The Dormouse Monitor