The hazel dormouse or common dormouse (''Muscardinus avellanarius'') is a small
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
and the only living species in the genus ''Muscardinus''.
Distribution and habitat
The hazel dormouse is native to northern Europe and Asia Minor. It is the only
dormouse
A dormouse is a rodent of the family Gliridae (this family is also variously called Myoxidae or Muscardinidae by different taxonomists). Dormice are nocturnal animals found in Africa, Asia, and Europe. They are named for their long, dormant hibe ...
native to the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
, and is therefore often referred to simply as the "dormouse" in British sources, although the
edible dormouse
''Glis'' is a genus of rodent that contains two extant species, both known as edible dormice or fat dormice: the European edible dormouse ''(Glis glis'') and the Iranian edible dormouse (''Glis persicus''). It also contains a number of fossil spec ...
, ''Glis glis'', has been accidentally introduced and now has an established population in South East England. Though
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
has no native dormouse, the hazel dormouse was discovered in
County Kildare
County Kildare ( ga, Contae Chill Dara) is a county in Ireland. It is in the province of Leinster and is part of the Eastern and Midland Region. It is named after the town of Kildare. Kildare County Council is the local authority for the county, ...
in 2010, and appears to be spreading rapidly, helped by the prevalence of
hedgerows
A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoini ...
in the Irish countryside.
The United Kingdom distribution of the hazel dormouse can be found on the
National Biodiversity Network website A 2020 study found that hazel dormice in Britain have declined by 51% since 2000. Woodland habitat loss and management and a warming climate are seen as material threats to their future status.
[
]
Habitat
According to
English Nature
English Nature was the United Kingdom government agency that promoted the conservation of wildlife, geology and wild places throughout England between 1990 and 2006. It was a non-departmental public body funded by the Department for Environmen ...
's ''Dormouse Conservation Handbook'', hazel dormice are "particularly associated with
deciduous woodland" but also inhabit hedgerows and scrub.
Dormice seldom travel more than 70 m from their nest.
Description
![Gliridae - Muscardinus avellanarius (Dormouse)-001](https://upload.wikimedia.org/wikipedia/commons/5/53/Gliridae_-_Muscardinus_avellanarius_%28Dormouse%29-001.JPG)
The hazel dormouse can reach a body length of about and a length of about if you consider the tail as well. It is long with a tail of . It weighs , although this increases to 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
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
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 from October to April–May.
Behaviour
Starting from the onset of colder weather (October/November), the hazel dormouse will hibernate in nests on the ground, in 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
Honeysuckles are arching shrubs or twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both contin ...
bark, fresh leaves and grasses in the undergrowth. If the weather is cold and wet, and food scarce, it saves energy by going into
torpor
Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time ...
; 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.
![Muscardinus avellanarius con piccolo 2](https://upload.wikimedia.org/wikipedia/commons/c/cf/Muscardinus_avellanarius_con_piccolo_2.jpg)
Examination of
hazelnut
The hazelnut is the fruit of the hazel tree and therefore includes any of the nuts deriving from species of the genus ''Corylus'', especially the nuts of the species ''Corylus avellana''. They are also known as cobnuts or filberts according t ...
s may show a neat, round hole in the shell. This indicates it has been opened by a small
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
, e.g., the dormouse,
wood mouse
The wood mouse (''Apodemus sylvaticus'') is a murid rodent native to Europe and northwestern Africa. It is closely related to the yellow-necked mouse (''Apodemus flavicollis'') but differs in that it has no band of yellow fur around the neck, ha ...
, or
bank vole
The bank vole (''Myodes glareolus'') is a small vole with red-brown fur and some grey patches, with a tail about half as long as its body. A rodent, it lives in woodland areas and is around in length. The bank vole is found in much of Europe an ...
. Other animals, such as
squirrel
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...
s or
jay
A jay is a member of a number of species of medium-sized, usually colorful and noisy, passerine birds in the Crow family, Corvidae. The evolutionary relationships between the jays and the magpies are rather complex. For example, the Eurasian m ...
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.
Diet
The hazel dormouse requires a variety of arboreal foods to survive. It eats berries and nuts and other fruit with
hazel
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
nuts being the main food for fattening up before hibernation.
The dormouse also eats
hornbeam
Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.
Origin of names
The common English name ''hornbeam' ...
and
blackthorn
''Prunus spinosa'', called blackthorn or sloe, is a species of flowering plant in the rose family Rosaceae. The species is native to Europe, western Asia, and regionally in northwest Africa. It is locally naturalized in New Zealand, Tasmania, ...
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
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
s and
caterpillar
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...
s.
Plants of value to dormice
*
Hazel
The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
is the principal food source, supports insects, forms an understory of poles, especially when
coppiced
Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeate ...
, which makes it useful for its
arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
activity. The hazel dormouse's Latin name ''avellanarius'' means "hazel".
*
Oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
s supply insect and flower food; the acorns are of little value.
*
Honeysuckle
Honeysuckles are arching shrubs or twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both contin ...
bark is their primary nesting material, and flowers and fruit are used for food.
*
Bramble
A bramble is any rough, tangled, prickly shrub, usually in the genus ''Rubus'', which grows blackberries, raspberries, or dewberries. "Bramble" is also used to describe other prickly shrubs, such as roses (''Rosa'' species). The fruits inclu ...
flowers and fruits provide food over a long period. The thorns give protection for nests. Dormice thrive on blackberries.
*
Alder buckthorn
''Frangula alnus'', commonly known as alder buckthorn, glossy buckthorn, or breaking buckthorn, is a tall deciduous shrub in the family Rhamnaceae. Unlike other "buckthorns", alder buckthorn does not have thorns. It is native to Europe, northern ...
– in parts of the dormouse range where hazel is scarce or absent, berries of alder buckthorn is the principal food source and vital for the accumulation of fat reserves in autumn prior to hibernation.
*
Willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
– unripe seeds in early spring.
*
Birch
A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...
– seeds.
*
Hawthorn
Hawthorn or Hawthorns may refer to:
Plants
* '' Crataegus'' (hawthorn), a large genus of shrubs and trees in the family Rosaceae
* ''Rhaphiolepis'' (hawthorn), a genus of about 15 species of evergreen shrubs and small trees in the family Rosace ...
flowers are an important food in the spring. The fruit is eaten occasionally.
*
Blackthorn
''Prunus spinosa'', called blackthorn or sloe, is a species of flowering plant in the rose family Rosaceae. The species is native to Europe, western Asia, and regionally in northwest Africa. It is locally naturalized in New Zealand, Tasmania, ...
– fruits (blackthorn fruit is called "sloe").
*
Ash
Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
– seed keys whilst they are still on the tree.
*
Sycamore
Sycamore is a name which has been applied to several types of trees, but with somewhat similar leaf forms. The name derives from the ancient Greek ' (''sūkomoros'') meaning "fig-mulberry".
Species of trees known as sycamore:
* ''Acer pseudoplata ...
supplies insects and pollen, and a habitat. However, they cast a dense shade which decreases the understory.
*
Hornbeam
Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere.
Origin of names
The common English name ''hornbeam' ...
– seeds.
*Wayfaring tree (''
Viburnum lantana
''Viburnum lantana'', the wayfarer or wayfaring tree, is a species of '' Viburnum'', native to central, southern and western Europe (north to Yorkshire in England), northwest Africa, and southwestern Asia.Blamey, M. & Grey-Wilson, C. (1989). ' ...
'') – fruits and flowers.
*
Broom
A broom (also known in some forms as a broomstick) is a cleaning tool consisting of usually stiff fibers (often made of materials such as plastic, hair, or corn husks) attached to, and roughly parallel to, a cylindrical handle, the broomstick. I ...
– flowers (in early summer).
*
Yew – fruits are a favoured food.
*
Sweet chestnut
''Castanea sativa'', the sweet chestnut, Spanish chestnut or just chestnut, is a species of tree in the family Fagaceae, native to Southern Europe and Asia Minor, and widely cultivated throughout the temperate world. A substantial, long-lived ...
provides an excellent foodsource, and the flowers are eaten, as well.
Threats
* Predation from
Eurasian badger
The European badger (''Meles meles''), also known as the Eurasian badger, is a badger species in the family Mustelidae native to almost all of Europe. It is classified as least concern on the IUCN Red List as it has a wide range and a large stabl ...
,
fox
Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush'').
Twelve sp ...
,
stoat
The stoat (''Mustela erminea''), also known as the Eurasian ermine, Beringian ermine and ermine, is a mustelid native to Eurasia and the northern portions of North America. Because of its wide circumpolar distribution, it is listed as Least Conc ...
,
weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender bo ...
, and
domestic cat
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members o ...
.
* Trampling by larger animals.
* Lack of food source, e.g., from too frequent hedge-trimming, or competition from other species, e.g.,
squirrel
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...
s.
* Destruction of
forest
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
and hedgerow habitats, or their diverse range of species, as a broad spectrum of food is required across the calendar year.
* Reduction in traditional forest management.
* A warming climate.
Protection status
The hazel dormouse is protected by and in UK under the
Wildlife and Countryside Act
The Wildlife and Countryside Act 1981 is an Act of Parliament in the United Kingdom implemented to comply with European Council Directive 79/409/EEC on the conservation of wild birds. In short, the act gives protection to native species (especia ...
.
Dormouse: European protected species
Natural England Species Information Note SIN005 (19 October 2007)
References
External links
The Mammal Society
site with a Hazel dormouse fact sheet. There is also a book entitled The Dormouse available, by Pat Morris.
Peoples Trust for Endangered Species
site describing the hazel dormouse and its conservation
Information and images
from the BBC #REDIRECT BBC #REDIRECT BBC
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