# Hazel dormouse > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Hazel_dormouse > Markdown URL: https://mediated.wiki/source/Hazel_dormouse.md > Source: https://en.wikipedia.org/wiki/Hazel_dormouse > Source revision: 1346753117 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Species of rodent}} {{Use dmy dates|date=June 2020}} {{Speciesbox | name = Hazel dormouse | fossil_range = {{fossilrange|Early Pleistocene|Recent}} | image = Haselmaus.jpg | status = LC | status_system = IUCN3.1 | status_ref = {{cite iucn |author=Hutterer, R. |author2=Kryštufek, B. |author3=Yigit, N. |author4=Mitsain, G. |author5=Meinig, H. |author6=Juškaitis, R. |name-list-style=amp |title=''Muscardinus avellanarius'' |amends=2016 |article-number=e.T13992A197519168 |doi=10.2305/IUCN.UK.2021-1.RLTS.T13992A197519168.en |date=2021 |access-date=17 February 2022}} | status2 = VU | status2_system = IUCN3.1 | status2_ref = {{cite web |url=https://www.mammal.org.uk/science-research/population-review-red-list/ |title=Population Review Red List |publisher=The Mammal Society |access-date=28 June 2020}} (Great Britain) | parent_authority = [Kaup](/source/Johann_Jakob_Kaup), 1829 | display_parents = 2 | genus = Muscardinus | species = avellanarius | authority = ([Linnaeus](/source/Carl_Linnaeus), [1758](/source/10th_edition_of_Systema_Naturae)) | synonyms = ''Mus avellanarius'' {{small|Linnaeus, 1758}} | range_map = Muscardinus avellanarius distribution.svg | range_map_caption = Geographic range }} The '''hazel dormouse''' or '''common dormouse''' ('''''Muscardinus avellanarius''''') is a small [dormouse](/source/dormouse) species native to Europe and the only living species in the [genus](/source/genus) '''''Muscardinus'''''.{{cite book |author=Mitchell-Jones, A. J. |author2=Amori, G. |author3=Bogdanowicz, W. |author4=Kryštufek, B. |author5=Reijnders, P.J.H. |author6=Spitzenberger, F. |author7=Stubbe, M. |author8=Thissen, J.B.M. |author9=Vohralik, V. |author10=Zima, J. |name-list-style=amp |year=1999 |title=The atlas of European Mammals |publisher=Academic Press |location=London |page=484}} ==Distribution and habitat== The hazel dormouse is native to northern Europe and Asia Minor. It is the only [dormouse](/source/dormouse) native to the [British Isles](/source/British_Isles), and is therefore often referred to simply as the "dormouse" in British sources, although the [edible dormouse](/source/edible_dormouse), ''Glis glis'', has been accidentally introduced and now has an established population in South East England. Though [Ireland](/source/Ireland) has no native dormouse, the hazel dormouse was discovered in [County Kildare](/source/County_Kildare) in 2010,{{cite journal |last1=Marnell |first1=Ferdia |last2=Donoher |first2=Daniel |first3=Emma |last3=Sheehy |first4=Colin |last4=Lawton |date=2013 |title=First confirmed record of Hazel Dormouse (''Muscardinus avellanarius'') in the wild in Ireland |journal=Irish Naturalists' Journal |volume=33 |number=1 |pages=77–78 |url=https://www.researchgate.net/publication/259266346 |via=ResearchGate}}{{Cite news |last=Ahlstrom |first=Dick |date=16 July 2013 |title=The dormouse makes first appearance in Ireland |url=https://www.irishtimes.com/news/science/the-dormouse-makes-first-appearance-in-ireland-1.1464474 |work=Irish Times}} and appears to be spreading rapidly, helped by the prevalence of [hedgerows](/source/hedgerows) in the Irish countryside.{{Cite news |last=Mooney |first=John |date=8 September 2013 |title=Rare UK dormouse moved to Ireland |url=https://www.thetimes.com/article/rare-uk-dormouse-moves-to-ireland-pr6rpv9r3q6 |work=Sunday Times}} The United Kingdom distribution of the hazel dormouse can be found on the National Biodiversity Network's website.{{cite web|title=NBN: Hazel dormouse|url=https://data.nbn.org.uk/Taxa/NHMSYS0000080214|access-date=25 October 2025}} Woodland habitat loss and management, together with the effects of climate change,{{cite news|work=BBC News|title=New population of rare dormice found in Sussex|first=Bob|last=Dale|date=25 October 2025|url=https://www.bbc.co.uk/news/articles/cy7ex3m2346o|access-date=25 October 2025}} are seen as material threats to their future status. {{cite news | first = Robyn| last = Vinter | title = Hedgerow highway will keep dormice thriving in the Yorkshire Dales | date = 18 April 2020 | newspaper = The Guardian | location = London, UK | url = https://www.theguardian.com/environment/2021/apr/18/hedgerow-highway-will-keep-dormice-thriving-in-the-yorkshire-dales | access-date = 18 April 2020 }} Its population is estimated to have declined by 72% from 1993 to 2014.{{Cite journal |last1=Goodwin |first1=Cecily E. D. |last2=Hodgson |first2=David J. |last3=Al-Fulaij |first3=Nida |last4=Bailey |first4=Sallie |last5=Langton |first5=Steve |last6=Mcdonald |first6=Robbie A. |date=2017 |title=Voluntary recording scheme reveals ongoing decline in the United Kingdom hazel dormouse Muscardinus avellanarius population |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/mam.12091 |journal=Mammal Review |language=en |volume=47 |issue=3 |pages=183–197 |doi=10.1111/mam.12091 |bibcode=2017MamRv..47..183G |issn=1365-2907}} ===Habitat=== According to [English Nature](/source/English_Nature)'s ''Dormouse Conservation Handbook'', hazel dormice are "particularly associated with [deciduous woodland](/source/Temperate_deciduous_forest)" but also inhabit hedgerows and scrub. In relation to its habitat, the hazel dormouse abundance was greater on sites with more honeysuckle, yew, and birch.{{Cite journal |last1=Goodwin |first1=Cecily E. D. |last2=Suggitt |first2=Andrew J. |last3=Bennie |first3=Jonathan |last4=Silk |first4=Matthew J. |last5=Duffy |first5=James P. |last6=Al-Fulaij |first6=Nida |last7=Bailey |first7=Sallie |last8=Hodgson |first8=David J. |last9=McDonald |first9=Robbie A. |date=2018 |title=Climate, landscape, habitat, and woodland management associations with hazel dormouse Muscardinus avellanarius population status |url=https://onlinelibrary.wiley.com/doi/10.1111/mam.12125 |journal=Mammal Review |language=en |volume=48 |issue=3 |pages=209–223 |doi=10.1111/mam.12125 |bibcode=2018MamRv..48..209G |issn=1365-2907}} Dormice seldom travel more than {{cvt|70|m}} from their nest.Paul Bright, Pat Morris & Tony Mitchell-Jones, ''[https://ptes.org/wp-content/uploads/2014/06/Dormouse-Conservation-Handbook.pdf The Dormouse Conservation Handbook]'' (2nd ed.: [English Nature](/source/English_Nature), 2006), p. 13. ==Description == [[File: Gliridae - Muscardinus avellanarius (Dormouse)-001.JPG|thumb|Hazel dormouse on ''[Epilobium](/source/Epilobium)'']] The hazel dormouse can reach a body length of about {{convert|10|cm}} and a length of about {{convert|16|cm}} if you consider the tail as well. It is {{Convert|6|to|9|cm|abbr=on}} long with a tail of {{Convert|5.7|to|7.5|cm|abbr=on}}. It weighs {{Convert|17|to|20|g|abbr=on}}, although this increases to {{Convert|30|to|40|g}} just before hibernation. This small mammal has reddish brown fur that can vary up to golden-brown or yellow-orange-brown becoming lighter in the lower part. Eyes are large and black. Ears are small and not very developed, while the tail is long and completely covered with hair. It is a [nocturnal](/source/nocturnal) creature and spends most of its waking hours among the branches of trees looking for food. It will make long detours rather than come down to the ground and expose itself to danger. The hazel dormouse [hibernates](/source/Hibernation) from October to April–May. ==Behaviour== {{Unreferenced section|date=February 2023|find=hazel dormouse behaviour}} Starting from the onset of colder weather (October or November), the hazel dormouse will hibernate in nests on the ground, at the base of old coppiced trees or hazel stools, under piles of leaves, or under log piles, as these situations are not subject to extreme variations in either temperature or humidity. Dormice are almost completely arboreal in habit but much less reluctant to cross open ground than was thought even recently. When it wakes up in spring (late April or early May), it builds woven nests of shredded [honeysuckle](/source/honeysuckle) bark, fresh leaves, and grasses in the undergrowth. If the weather is cold and wet and food is scarce, it saves energy by going into [torpor](/source/torpor); it curls up into a ball and goes to sleep. The hazel dormouse, therefore, spends a large proportion of its life sleeping, either hibernating in winter or in torpor in summer. thumb|220px|right|''M. avellanarius'' moving a newborn baby An examination of [hazelnut](/source/hazelnut)s may show a neat, round hole in the shell. This indicates it has been opened by a small [rodent](/source/rodent), e.g. the dormouse, [wood mouse](/source/wood_mouse), or [bank vole](/source/bank_vole). Other animals, such as [squirrel](/source/squirrel)s or [jay](/source/jay)s, will either split the shell completely in half or make a jagged hole in it. Further examination reveals the cut surface of the hole has toothmarks which follow the direction of the shell. In addition, there will be toothmarks on the outer surface of the nut, at an angle of about 45 degrees to the cut surface. Woodmice and voles bite across the nutshell leaving clear parallel toothmarks from inside to outside. Woodmice also leave toothmarks on the outer surface of the nut but voles do not. [[File: Dormouse1.jpg|thumb|A [hibernating](/source/hibernation) hazel dormouse.]] ==Diet== The hazel dormouse requires a variety of arboreal foods to survive. It eats berries and nuts and other fruit with [hazel](/source/hazel)nuts being the main food for fattening up before hibernation. The dormouse also eats [hornbeam](/source/hornbeam) and [blackthorn](/source/blackthorn) fruit where hazel is scarce. Other food sources are the buds of young leaves, and flowers which provide nectar and pollen. The dormouse also eats insects found on food-source trees, particularly [aphid](/source/aphid)s and [caterpillar](/source/caterpillar)s. ===Plants of value to dormice=== {{more citations needed|section|date=January 2022}} *[Hazel](/source/Corylus_avellana) is the principal food source, supports insects, forms an understory of poles, especially when [coppiced](/source/coppiced), which makes it useful for its [arboreal](/source/arboreal) activity. The hazel dormouse's Latin name ''avellanarius'' means "hazel". *[Oak](/source/Oak)s supply insect and flower food; the acorns are of little value. *[Honeysuckle](/source/Honeysuckle) bark is their primary nesting material, and flowers and fruit are used for food. *[Bramble](/source/Bramble) flowers and fruits provide food over a long period. The thorns give protection for nests. Dormice thrive on blackberries. *[Alder buckthorn](/source/Frangula_alnus) – in parts of the dormouse range where hazel is scarce or absent, berries of alder buckthorn are the principal food source and vital for the accumulation of fat reserves in autumn prior to hibernation.{{cite journal |url=https://www.researchgate.net/publication/256092587 |title=Feeding on the edge: the diet of the hazel dormouse Muscardinus avellanarius (Linnaeus 1758) on the northern periphery of its distributional range |journal=Mammalia |volume=77 |number=2 |pages=149–155 |first1=Rimvydas |last1=Juškaitis |first2=Laima |last2=Baltrunaite |year=2013 |doi=10.1515/mammalia-2012-0086 |s2cid=84754901 |access-date=28 June 2020}} *[Willow](/source/Willow) – unripe seeds in early spring. *[Birch](/source/Birch) – seeds. *[Hawthorn](/source/Crataegus_monogyna) flowers are an important food in the spring. The fruit is eaten occasionally.[http://ptes.org/index.php?cat=110 Hedgerows for Dormice] {{Webarchive|url=https://web.archive.org/web/20091128044656/http://www.ptes.org/index.php?cat=110 |date=28 November 2009 }}. Ptes.org. Retrieved on 28 December 2012. *[Blackthorn](/source/Blackthorn) – fruits (blackthorn fruit is called "sloe"). *[Ash](/source/Fraxinus) – seed keys whilst they are still on the tree. *[Sycamore](/source/Acer_pseudoplatanus) supplies insects and pollen, and a habitat. However, they cast a dense shade which decreases the understory. *[Hornbeam](/source/Hornbeam) – seeds. *Wayfaring tree (''[Viburnum lantana](/source/Viburnum_lantana)'') – fruits and flowers. *[Broom](/source/Broom_(shrub)) – flowers (in early summer). *[Yew](/source/taxus) – fruits are a favoured food. *[Sweet chestnut](/source/Sweet_chestnut) provides an excellent foodsource, and the flowers are eaten, as well. == Threats == * Predation from [fox](/source/fox)es, [wild boar](/source/wild_boar)s, [weasel](/source/weasel)s, [owl](/source/owl)s and [domestic cat](/source/domestic_cat)s.{{Cite web |last=Trust |first=Woodland |title=Hazel Dormouse (Muscardinus avellanarius) |url=https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/hazel-dormouse/ |access-date=2023-02-03 |website=Woodland Trust |language=en-GB}}Verbeylen, Goedele. [https://www.researchgate.net/profile/Goedele-Verbeylen/publication/333220910_How_small_should_the_entrance_be_Is_it_possible_to_let_common_dormice_Muscardinus_avellanarius_enter_nest_boxes_and_exclude_other_species/links/5ce2c4f5299bf14d95aa768c/How-small-should-the-entrance-be-Is-it-possible-to-let-common-dormice-Muscardinus-avellanarius-enter-nest-boxes-and-exclude-other-species.pdf "How small should the entrance be? Is it possible to let common dormice Muscardinus avellanarius enter nest boxes and exclude other species.]" (2017): 35-39. * Being dug up or disturbed during hibernation by [badger](/source/badger)s.{{Cite book |last=Moffat |first=Ruth |url=https://www.exploredunsmore.org/wp-content/uploads/2018/04/The-Status-of-the-Hazel-Dormouse-in-Warwickshire-in-2016.pdf |title=THE STATUS OF THE HAZEL DORMOUSE(Muscardinus avellanarius) IN WARWICKSHIRE, COVENTRY & SOLIHULL IN 2016 |publisher=Warwickshire Dormouse Conservation Group |year=2017 |page=6 |language=en}} * Lack of food source, e.g., from too frequent hedge-trimming, or competition from other species, e.g., [squirrel](/source/squirrel)s, other dormouse species, mice. * Destruction of [forest](/source/forest) and hedgerow habitats, or their diverse range of species, as a broad spectrum of food is required across the calendar year.{{cite web |title=New report reveals Britain's hazel dormice decline |url=https://nbn.org.uk/news/new-report-reveals-britains-hazel-dormice-decline/ |website=National Biodiversity Network Trust |date=20 November 2019 |access-date=8 November 2021}}{{Cite book |last=Maclean |first=Norman |url=https://books.google.com/books?id=o_UPUCbekugC&dq=Muscardinus+avellanarius+badger&pg=PA254 |title=Silent Summer: The State of Wildlife in Britain and Ireland |date=2010-05-20 |publisher=Cambridge University Press |isbn=978-0-521-51966-3 |language=en}} * Reduction in traditional forest management.{{cite web |title=The State of Britain's Dormice 2019 |url=https://ptes.org/wp-content/uploads/2019/11/SoBD-2019.pdf |website=People's Trust for Endangered Species |access-date=8 November 2021}} * A warming climate. ==Protection status== The hazel dormouse is protected by and in UK under the [Wildlife and Countryside Act](/source/Wildlife_and_Countryside_Act).[http://www.ptes.org/files/284_dormouse_nat_eng_fact_sheet.pdf Dormouse: European protected species] {{Webarchive|url=https://web.archive.org/web/20120917005558/http://www.ptes.org/files/284_dormouse_nat_eng_fact_sheet.pdf |date=17 September 2012 }}. Natural England Species Information Note SIN005 (19 October 2007) At European level, the hazel dormouse is classed as In Need of Strict Protection under annex IV of the [Habitats Directive](/source/Habitats_Directive) 92/43/EEC "Gliridae - All species except Glis glis and Eliomys quercinus".{{cite web | title=Consolidated TEXT: 31992L0043 — EN — 01.07.2013 | url=https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:01992L0043-20130701#anx_IV }} == Evolutionary history == The oldest fossils of the genus ''Muscardinus'' date to the [Serravallian](/source/Serravallian) stage of the Middle [Miocene](/source/Miocene) approximately 13.8 to 11.6 million years ago in what is now Spain. The oldest fossils of the modern species date to the [Early Pleistocene](/source/Early_Pleistocene).{{Cite journal |last1=Garcia-Ibaibarriaga |first1=Naroa |last2=Arrizabalaga |first2=Álvaro |last3=Iriarte-Chiapusso |first3=María-José |last4=Rofes |first4=Juan |last5=Murelaga |first5=Xabier |date=July 2015 |title=The return to the Iberian Peninsula: first Quaternary record of Muscardinus and a palaeogeographical overview of the genus in Europe |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379115001596 |journal=Quaternary Science Reviews |language=en |volume=119 |pages=106–115 |bibcode=2015QSRv..119..106G |doi=10.1016/j.quascirev.2015.04.017 |hdl-access=free |hdl=10810/65159}} == References == {{Reflist|2}} == External links == {{Commons category|Muscardinus avellanarius}} *[http://www.mammal.org.uk/index.php?option=com_content&view=article&id=217&Itemid=250 The Mammal Society] {{Webarchive|url=https://web.archive.org/web/20120330225516/http://www.mammal.org.uk/index.php?option=com_content&view=article&id=217&Itemid=250 |date=30 March 2012 }} site with a Hazel dormouse fact sheet. There is also a book entitled The Dormouse available, by Pat Morris. *[http://www.ptes.org/index.php?cat=123 Peoples Trust for Endangered Species] site describing the hazel dormouse and its conservation *[https://web.archive.org/web/20030731142419/http://www0.bbc.co.uk/nature/wildfacts/factfiles/263.shtml Information and images] from the [BBC](/source/BBC) *[http://www.the-piedpiper.co.uk/th1k.htm Extensive information and pictures] *[http://britishwildlifehelpline.com/Hazel_Dormouse.html Pet care] *[https://web.archive.org/web/20071022170147/http://www.wildlife-web.org.uk/dormouse/ A lot of facts, links and book reviews about the dormouse] *[https://web.archive.org/web/20120917005558/http://www.do-it.org.uk/files/makathondoormousebox.pdf Dormouse nest-box construction] {{Gliridae nav}} {{Sciuromorpha|state=collapsed}} {{Taxonbar|from=Q207148}} {{Authority control}} Category:Dormice Category:Mammals of Asia Category:Rodents of Europe Category:Mammals of Russia Category:Mammals of Turkey Category:Mammals described in 1758 Category:Animal taxa named by Carl Linnaeus --- Adapted from the Wikipedia article [Hazel dormouse](https://en.wikipedia.org/wiki/Hazel_dormouse) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Hazel_dormouse?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.