The dormouse is a rodent of the family Gliridae. (This family is also variously called Myoxidae or Muscardinidae by different taxonomists.) Dormice are mostly found in Europe, although some live in Africa and Asia. They are particularly known for their long periods of hibernation. Because only one species of dormouse is native to the British Isles, in everyday English usage dormouse usually refers to one species (the hazel dormouse) as well as to the family as a whole.
Dormice are small rodents, with body lengths between 6 and 9 cm (2.4 and 3.5 in), and weights between 15 and 35 g (0.53 and 1.2 oz). They are generally mouse-like in appearance, but with furred, rather than scaly tails. They are largely but not exclusively 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, typically feeding on fruits, berries, flowers, nuts and insects. 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 (in a good year) twice a 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.
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 remains sufficiently cool, 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.
Their name is based on this trait; it comes from Anglo-Norman dormeus, which means "sleepy (one)"; the word was later altered by folk etymology to resemble the word "mouse". The sleepy behaviour of the dormouse character in Lewis Carroll's Alice's Adventures in Wonderland also attests to this trait.
Relationship with humans
The edible dormouse 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 rear dormice for the table. Dormice to this day are hunted and eaten in Slovenia. Dormouse fat was used by the Elizabethans to induce sleep.
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, such as Leithia melitensis, lived on the islands of Malta and Sicily.
The family consists of 29 living species, in three subfamilies and (arguably) 9 genera:
FAMILY Gliridae – Dormice
- Subfamily Graphiurinae
- Genus Graphiurus, African dormice
- Angolan African dormouse, Graphiurus angolensis
- Christy's dormouse, Graphiurus christyi
- Jentink's dormouse, Graphiurus crassicaudatus
- Johnston's African dormouse, Graphiurus johnstoni
- Kellen's dormouse, Graphiurus kelleni
- Lorrain dormouse, Graphiurus lorraineus
- Small-eared dormouse, Graphiurus microtis
- Monard's dormouse, Graphiurus monardi
- Woodland dormouse, Graphiurus murinus
- Nagtglas's African dormouse, Graphiurus nagtglasii
- Spectacled dormouse, Graphiurus ocularis
- Rock dormouse, Graphiurus platyops
- Stone dormouse, Graphiurus rupicola
- Silent dormouse, Graphiurus surdus
- Graphiurus walterverheyeni 
- Genus Graphiurus, African dormice
- Subfamily Leithiinae
- Genus Chaetocauda
- Genus Dryomys
- Genus Eliomys, garden dormice
- Genus Hypnomys† (Balearic dormouse)
- Genus Muscardinus
- Genus Myomimus, mouse-tailed dormice
- Genus Selevinia
- Subfamily Glirinae
- Subfamily Bransatoglirinae
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