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 hibernation period of six months or longer.

As only one species of dormouse – the hazel dormouse – is native to the United Kingdom, in everyday English usage "dormouse" can refer either to that one species or to the family as a whole.

The English name of the species derived from the French ''dormeuse'', and the latter in turn possibly from the Languedocien ''radourmeire''.

Etymology

Concerning the dormouse's name, etymonline says "long-tailed Old World rodent noted for its state of semi-hibernation in winter, early 15c., possibly from Anglo-French ''dormouse'' 'tending to be dormant' (from stem of ''dormir'' 'to sleep,' see ''dormant''), with the second element mistaken for ''mouse''; or perhaps it is from a Middle English dialectal compound of ''mouse'' (n.) and Middle French ''dormir''. French ''dormeuse'', fem. of ''dormeur'' 'sleeper' is attested only from 17c."

Characteristics

Dormice are small rodents, with body lengths between , and weight between . They are generally mouse-like in appearance, but with furred, rather than scaly, tails. They are largely arboreal, agile, and well adapted to climbing. Most species are nocturnal. Dormice have an excellent sense of hearing and signal each other with a variety of vocalisations.

Dormice are omnivorous, and typically feed on berries, flowers, fruits, insects, and nuts. They are unique among rodents in that they lack a cecum, a part of the gut used in other species to ferment vegetable matter. Their dental formula is similar to that of squirrels, although they often lack premolars:

Dormice breed once or occasionally twice each year, producing litters with an average of four young after a gestation period of 22–24 days. They can live for as long as five years. The young are born hairless and helpless, and their eyes do not open until about 18 days after birth. They typically become sexually mature after the end of their first hibernation. Dormice live in small family groups, with home ranges that vary widely between species and depend on the availability of food.

Hibernation

One of the most notable characteristics of those dormice that live in temperate zones is hibernation. They can hibernate six months out of the year, or even longer if the weather does not become warm enough, sometimes waking for brief periods to eat food they had previously stored nearby. During the summer, they accumulate fat in their bodies to nourish them through the hibernation period.

Relationship with humans

The edible dormouse (''Glis glis'') was considered a delicacy in ancient Rome, either as a savoury appetizer or as a dessert (dipped in honey and poppy seeds). The Romans used a special kind of enclosure, a glirarium, to raise and fatten dormice for the table. It is still considered a delicacy in Slovenia and in several places in Croatia, namely Lika, and the islands of Hvar and Brač. Dormouse fat was believed by the Elizabethans to induce sleep since the animal put on fat before hibernating.

In more recent years dormice have begun to enter the pet trade, though they are uncommon as pets and are considered an exotic pet. The woodland dormouse (''Graphiurus murinus)'' is the most commonly seen species in the pet trade. Asian garden dormice (''Eliomys melanurus'') are also occasionally kept as pets.

Evolution

The Gliridae are one of the oldest extant rodent families, with a fossil record dating back to the early Eocene. As currently understood, they descended in Europe from early Paleogene ischyromyids such as ''Microparamys'' (''Sparnacomys'') ''chandoni''. The early and middle Eocene genus ''Eogliravus'' represents the earliest and most primitive glirid taxon; the oldest species, ''Eogliravus wildi'', is known from isolated teeth from the early Eocene of France and a complete specimen of the early middle Eocene of the Messel pit in Germany. They appear in Africa in the upper Miocene and only relatively recently in Asia. Many types of extinct dormouse species have been identified. During the Pleistocene, giant dormice the size of large rats, ''Leithia melitensis'', lived on the islands of Malta and Sicily.

Classification

The family consists of 29 extant species, in three subfamilies and (arguably) nine genera:

Family Gliridae – Dormice
* Subfamily Glirinae
** Genus ''Glirulus''
*** Japanese dormouse, ''Glirulus japonicus''
** Genus ''Glis''
*** European edible dormouse, ''Glis glis''
***Iranian edible dormouse, ''Glis persicus''
* Subfamily Graphiurinae
** Genus ''Graphiurus'', African dormice
*** Angolan African dormouse, ''Graphiurus angolensis''
*** Christy's dormouse, ''Graphiurus christyi''
*** ''Graphiurus walterverheyeni''
*** Jentink's dormouse, ''Graphiurus crassicaudatus''
*** Johnston's African dormouse, ''Graphiurus johnstoni''
*** Kellen's dormouse, ''Graphiurus kelleni''
*** Lorrain dormouse, ''Graphiurus lorraineus''
*** Monard's dormouse, ''Graphiurus monardi''
*** Nagtglas's African dormouse, ''Graphiurus nagtglasii''
*** Rock dormouse, ''Graphiurus platyops''
*** Silent dormouse, ''Graphiurus surdus''
*** Small-eared dormouse, ''Graphiurus microtis''
*** Spectacled dormouse, ''Graphiurus ocularis''
*** Stone dormouse, ''Graphiurus rupicola''
*** Woodland dormouse, ''Graphiurus murinus''
* Subfamily Leithiinae
** Genus ''Chaetocauda''
*** Chinese dormouse, ''Chaetocauda sichuanensis''
** Genus ''Dryomys''
*** Balochistan forest dormouse, ''Dryomys niethammeri''
*** Forest dormouse, ''Dryomys nitedula''
*** Woolly dormouse, ''Dryomys laniger''
** Genus ''Eliomys'', garden dormice
***Asian garden dormouse, ''Eliomys melanurus''
*** Garden dormouse, ''Eliomys quercinus''
*** Maghreb garden dormouse, ''Eliomys munbyanus''
** Genus ''Hypnomys''† (Balearic dormouse)
*** Majorcan giant dormouse, ''Hypnomys morphaeus''†
*** Minorcan giant dormouse, ''Hypnomys mahonensis''†
** Genus ''Leithia''†
*** ''Leithia cartei''†
*** Maltese giant dormouse, ''Leithia melitensis''†
** Genus ''Muscardinus''
*** Hazel dormouse, ''Muscardinus avellanarius''
** Genus ''Myomimus'', mouse-tailed dormice
*** Masked mouse-tailed dormouse, ''Myomimus personatus''
*** Roach's mouse-tailed dormouse, ''Myomimus roachi''
*** Setzer's mouse-tailed dormouse, ''Myomimus setzeri''
** Genus ''Selevinia''
*** Desert dormouse, ''Selevinia betpakdalaensis''

Fossil species

* Subfamily Bransatoglirinae
** Genus '' Bransatoglis''
*** '' Bransatoglis adroveri'' Majorca, Early Oligocene
*** '' Bransatoglis planus'' Eurasia, Early Oligocene
** Genus '' Oligodyromys''

References

Further reading

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External links

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Glirarium.org

{{Authority control

Natural monuments of Japan
Extant Eocene first appearances