Glis glis

Geographic Range

Fat dormice are found throughout most of Europe and parts of western Asia. The range expands as far south as Italy and northern Turkey, and as far north as Latvia. The westernmost range lies in northern Spain, extending throughout Europe and into portions of western Russia and northern Iran. Populations have also been found on several Mediterranean islands, including the British Isles. Range elevations have been recorded from sea level to 2,000 m.

• Biogeographic Regions
• palearctic palearctic
  • native native

Habitat

Prime habitat conditions include deciduous and mixed forested regions with large volumes of mast seeding trees. A dense understory with tall, “well-connected” tree canopies is ideal. Beech ( Fagus ) and oak ( Quercus ) habitats are preferred, whereas coniferous forests are avoided. Caves, tree cavities, and houses are also frequently inhabited (Krystufek, 2010). Lower altitudes, approximately 1200 to 1300 m above sea level, provide less thermal stress and higher tree strands, proving to be more desirable (Milazzo et al., 2003). Fat dormice shelter in the hollows of trees, rock crevices, burrows among tree roots, animal cavities, piles of debris, attics, barns, and nest boxes. They line their shelters with grass or other vegetation.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• urban urban
• suburban suburban

Physical Description

Dormice are small to medium sized rodents with short limbs, compact bodies, and bushy tails, bearing some resemblance to squirrels. They have four digits on their front feet and five on their hind feet, containing short, curved claws. They are myomorphous, but differ from other myomorphs in that their zygomatic plate is not as developed. Dormice have a dental formula of 1/1, 0/0, 0-1/0-1, 3/3 with a total of 16 or 20 teeth. (Myers and Poor, 2012). Characteristics of fat dormice that distinguish them from other dormice include lack of spines on the lateral pads of the glans penis, loss of sphenofrontal and stapedial foramina, shortened lateral pterygoid process and fossa pterygoida, concealment of m3 by the coronoid process in the lower jaw (lateral view), lack of perforation in the angular process of the lower jaw, and separation of protoloph and metaloph (Krystufek, 2010).

Glis glis is the largest of the dormice with a typical body length of 160 to 190 mm, tail length of up to 168 mm, and small ears relative to its body size. Differentiation in body size between sexes is not apparent (monomorphic). Individuals are gray in color with a white underside/belly and four to six pairs of nipples (Krystufek, 2010). Fat dormice gain substantial weight before entering hibernation seasonally.

• Other Physical Features
• endothermic endothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

Fat dormice are polygamous and promiscuous breeders. Females are territorial and remain within their home range. Males are not, allowing them to pursue available mates.

• Mating System
• polygynous polygynous

Unlike many mammals, fat dormice do not mate every year. Instead, reproduction occurs only in years with sufficient mast production. Mating season ranges from June to August, resulting in a single litter approximately one month after copulation. The average litter size is typically 5 young.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

Little is known about parental care in this species. However, as in most mammals, females take on the majority of parental care through gestation and lactation.

• Parental Investment
• altricial altricial
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Wild fat dormice have been known to live up to 12 years (Myers and Poor, 2012) but on average live approximately 9 years (Krystufek, 2010).

Behavior

Like most dormice , fat dormice are arboreal and nocturnal, spending most of the daytime hours in nests or tree cavities (Krystufek, 2010; Myers and Poor, 2012). A significant feature of their behavior is that they practice all three types of dormancy: daily torpor, hibernation, and aestivation. Daily torpor is present throughout the year in coordination with the other two dormancy types. Fat dormice are considered true hibernators, staying in their hibernacula from autumn to spring, living solely on fat stores (Wilz and Heldmaier, 2010). Their hibernacula are located in soil cavities. Despite the fact that dormice are primarily non-social, they do hibernate and occasionally share nests with close relatives (Krystufek, 2010).

• Key Behaviors
• arboreal arboreal
• scansorial
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• aestivation
• daily torpor
• solitary solitary
• territorial territorial

Home Range

Dormice rarely travel, except when searching for food. Males, however, have significantly larger home ranges than females (females are territorial). Home ranges in fat dormice are density dependent, depending on food availability rather than reproduction (Kryštufek, 2010).

Communication and Perception

Acoustic communication includes twitters, chirps, shrieks, churrs, whistles, tooth-chattering, and buzzing (in juveniles) (Hutterer and Peters, 2001). When and why these communications occur has not been extensively studied. Olfactory communication consists of marking territories with glandular excretions (Myers and Poor, 2012).

• Communication Channels
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Fat dormice are primarily herbivorous, but can be carnivorous. Beech mast, acorns, and hazelnuts are their main source of nutrition. Fleshy fruits (blackberries, apples, pears, etc.) also comprise a significant amount of their diet, especially in the summer months. Other sources of food include flowers and leaves, arthropods, fungi, mosses, invertebrates (slugs, caterpillars, aphids, myriapods, and beetles), and hole-nesting birds, but these are uncommon and tend only to be an option when primary food sources are not available (Krystufek, 2010).

• Primary Diet
• herbivore herbivore
  • frugivore frugivore
  • granivore granivore

• Animal Foods
• birds
• eggs
• insects
• terrestrial non-insect arthropods

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• fruit
• flowers
• bryophytes

• Other Foods
• fungus

• Foraging Behavior
• stores or caches food stores or caches food

Predation

There are at least 14 known vertebrates that prey on fat dormice. Owls are their main source of predation, including barn owls ( Tyto alba ), Eurasian tawny owls ( Strix aluco ), long-eared owls ( Asio otus ), and little owls ( Athene noctua ). Other predators include golden eagles ( Aquila chrysaetos ), roof rats ( Rattus rattus ), gray wolves ( Canis lupus ), red foxes ( Vulpes vulpes ), brown bears ( Ursus arctos ), European pine martens ( Martes martes ), wildcats ( Felis silvestris ), and wild boar ( Sus scrofa ) (Krystufek, 2010). The typical response to alarm is a bite, but may also include hissing, spitting, and leaping. Dormice also have the capability of tail regeneration if lost to predators (Myers and Poor, 2012).

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Dormice are primary consumers, eating nuts, fruits, mosses, and fungi. They can also be considered secondary consumers due to their occasional consumption of small invertebrates. In turn, they fall prey to owls and small carnivores (Krystufek, 2010). They are hosts to a wide variety of parasites.

• Ecosystem Impact
• parasite parasite

Economic Importance for Humans: Positive

Fat dormice are trapped and hunted for their soft fur as well as for meat (Myers and Poor, 2012). Some hunt this species recreationally (Amori et al., 2008).

• Positive Impacts
• food food
• body parts are source of valuable material

Economic Importance for Humans: Negative

Fat dormice are sometimes seen as a nuisance species, inhabiting homes and gardens. (Amori et al., 2008). They have also been known to strip trees of their bark, leading to decay and possible infection (Montecchi et al., 2010).

• Negative Impacts
• household pest

Conservation Status

Fat dormice are considered "least concern" by the IUCN because they are widespread, common, and tolerate human disturbance.

Other Comments

Glis glis was formerly referred to as Myoxus glis . It is the only extant species of the genus Glis (Krystufek, 2010).

Additional Links

Encyclopedia of Life

Contributors

Katie Fitzke (author), University of Wisconsin - Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, Tanya Dewey (editor), University of Michigan-Ann Arbor, Shaina Stewart (editor), University of Wisconsin - Stevens Point.

References

Amori, G., R. Hutterer, B. Kryštufek, N. Yigit, G. Mitsain, L. Muñoz, H. Meinig, R. Juškaitis. 2008. "Glis glis" (On-line). The IUCN Red List of Threatened Species. Accessed August 21, 2013 at http://www.iucnredlist.org/details/39316/0 .

Hutterer, R., G. Peters. 2001. "The vocal repertoIre of Graphiurus parvus, and comparIsons wIth other specIes of dormIce" (On-line pdf). Accessed August 21, 2013 at www.arastirmax.com/system/files/.../2/.../arastirmax_8475_pp_69-74.pdf‎ .

Kryštufek, B. 2010. "Glis glis (Rodentia: Gliridae)" (On-line pdf). Accessed August 21, 2013 at http://www.asmjournals.org/doi/full/10.1644/865.1 .

Milazzo, A., W. Falletta, M. Sara. 2003. "HABITAT SELECTION OF FAT DORMOUSE (GLIS GLIS ITALICUS) IN DECIDUOUS WOODLANDS OF SICILY" (On-line). Accessed August 21, 2013 at http://publication.nhmus.hu/pdf/actazool/ActaZH_2003_Vol_49_Suppl1_117.pdf .

Montecchio, L., L. Scattolin, R. De Battisti. 2010. "Dormouse injuries predispose beech to infection by Neonectria ditissima" (On-line). EBSCOhost. Accessed August 21, 2013 at http://web.ebscohost.com.ezproxy.uwsp.edu/ehost/pdfviewer/pdfviewer?sid=f04b5bbd-7fc6-491c-9083-2ff2b3952002%40sessionmgr11&vid=2&hid=24 .

Myers, P., A. Poor. 2012. "Gliridae:dormice and hazel mice" (On-line). Animal Diversity Web. Accessed August 21, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Gliridae.html#dbc1cc3d5d909d93a8ec634ab6a53e88 .

Wilz, M., G. Heldmaier. 2000. "Comparison of hibernation, estivation and daily torpor in the edible dormouse, Glis glis" (On-line pdf). Accessed August 21, 2013 at www.researchgate.net .