 Gliridae The family Gliridae (also variously called Myoxidae or Muscardinidae by different taxonomists) is commonly known as the dormouse (Italian ghiro; Croatian puh; Slovenian polh). Dormice are nocturnal rodents found in sub-Saharan Africa, in Europe north to southern Scandinavia, and in Asia east to southern China and Japan. The family Gliridae contains 28 (or 29) species in three subfamilies and (arguably) 9 genera. The subfamilies are:
The Gliridae family is one of the oldest extant rodent families, with a fossil record dating back to the early Eocene. It is smaller than it was in the past with more than 30 Gliridae genera having become extinct since the 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. Concerning the dormouse's name, etymonline says "long-tailed Old World rodent noted for its state of semi-hibernation in winter, early 15th century, 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 (also Latin and Italian) dormir (which means to sleep). French dormeuse, fem. of dormeur 'sleeper' is attested only from 17th century. The English name of the species derived from the French dormeuse, and the latter in turn possibly from the Languedocien radourmeire. Only one species of dormouse – the hazel dormouse – is native to the United Kingdom. Thus, in everyday English usage "dormouse" can refer either to that one species or to the family as a whole. Glirids live in temperate, subtropical, and tropical forests as well as shrubland, savannahs, the banks of rivers and streams, rocky outcrops, gardens, and agricultural areas. Species in the genus Selvinia inhabit desert scrub. Description Dormice are small to medium sized rodents with head-body lengths between 6 and 19 cm. (2.4 and 7.5 in.), and weigh between 15 and 180 g. (0.53 and 6.35 oz.). They are generally mouse-like in appearance, but with bushy rather than scaly tails (except members of the genera Selevinia and Myomimus), they also resemble squirrels or chipmunks. The limbs are relatively short; the feet are broad; and the toes are tipped with short, curved claws. Glirids have four functional digits on their forefeet and five on their hindfeet. Their bodies are covered with thick, soft fur. Some species have distinctive black facial markings. They are largely arboreal, with well-developed toe pads, thus 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. Lifespans of 4 years have been reported for Dryomys nitedula and Muscardinus avellanarius dormice. Eliomys quercinus and Graphiurus murinus each live 5 to 6 years in captivity, wherease the wild edible dormice (Glis) have been reported to live up to 12 years. Such a long lifespan may be attributed to the fact that entire populations skip breeding in poor mast years, allowing them to put more energy into survival.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. Behavior Most glirids are arboreal (live in trees), though some Eliomys, Dryomys, Graphiurus, and Myomimus are terrestria (ground dwellers). They construct characteristic globular nests of plant matter in trees, shrubs, rock piles, the burrows of other animals, and sometimes even in human habitations. Activity patterns are nocturnal and crepuscular (relating to twilight). Glirids living in temperate regions put on fat during the fall, then hibernate during inclement weather. 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. Muscardinus individuals, for example, have been reported to hibernate from August until May. Some glirid species are solitary and territorial for part of the year. Territory sizes of 13.9 hectares (34.3 acres) for males and 8.5 hectares (21 acres) for females have been reported for Graphiurus. Glis mark their territories with secretions from glands. Though males may fight in the breeding season, several indivdiuals may congregate in the same nest to hibernate. Muscardinus live in small colonies and also hibernate in groups, with up to 11 individuals sharing a nest. Reproduction Some glirid species (Graphiurus and Glis) are territorial and solitary except during the breeding season. Glis males have been observed fighting at this time, suggesting that they are polygynous. Nowak (1999) noted that while Glis males have been known to remain with females to help care for their young in captivity, in the wild males most likely leave to pursue other females. They breed once or occasionally twice each year in spring and summer, 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. Glirids breed in the spring and summer, though wild populations of edible dormice (Glis glis) may skip reproduction altogether in years of low food abundance. Females bear one to two litters per year, with 2 to 10 young per litter. The gestation period ranges from 21 to 30 days. Young open their eyes after about three weeks, and are weaned and independent after four to six weeks.Before giving birth, females construct soft, moss-lined nests in which to raise their offspring. Glirids are eutherian mammals; therefore, females provide their young with nutrients through the placenta and then through their milk. In captivity, male Glis glis have been known to help protect and clean their young, but this behavior has not been observed in the wild. Protection All species of dormouse, including the Glis glis, the edible dormouse, are protected from hunting under EU law. 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.
Sources:
|
||
|
Created: Thursday, December
24, 2020, Last updated:
Friday, December 31, 2021 |
