Animal Diversity Web

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. (Amori, et al., 2008)

• Biogeographic Regions
• palearctic
  • 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. (Kryštufek, 2010; Mi­lazzo, et al., 2003; Myers and Poor, 2012)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• forest

• Other Habitat Features
• urban
• suburban

• Range elevation

  0 to 2000 m

  0.00 to 6561.68 ft

• Average elevation

  1200 m

  3937.01 ft

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). (Kryštufek, 2010; Myers and Poor, 2012)

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. (Kryštufek, 2010)

• Other Physical Features
• endothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  120 to 150 g

  4.23 to 5.29 oz

• Range length

  160 to 190 mm

  6.30 to 7.48 in

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. (Kryštufek, 2010)

• Mating System
• 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. (Kryštufek, 2010)

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

• Breeding interval

  Fat dormice breed based on food availability rather than time intervals.

• Breeding season

  Breeding season ranges from June to August.

• Average number of offspring

  5

• Average gestation period

  1 months

• Average time to independence

  30 days

• Range age at sexual or reproductive maturity (female)

  351 to 380 days

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. (Myers and Poor, 2012)

• Parental Investment
• altricial
• 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). (Kryštufek, 2010; Myers and Poor, 2012)

• Typical lifespan
  Status: wild

  6 to 12 years

• Average lifespan
  Status: captivity

  8.7 years

  Max Planck Institute for Demographic Research

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). (Kryštufek, 2010; Wilz and Held­maier, 2000)

• Key Behaviors
• arboreal
• scansorial
• nocturnal
• motile
• sedentary
• hibernation
• aestivation
• daily torpor
• solitary
• 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). (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). (Hut­terer and Pe­ters, 2001; Myers and Poor, 2012)

• Communication Channels
• acoustic
• chemical

• Other Communication Modes
• scent marks

• Perception Channels
• visual
• tactile
• acoustic
• 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). (Kryštufek, 2010)

• Primary Diet
• herbivore
  • frugivore
  • 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

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). (Kryštufek, 2010; Myers and Poor, 2012)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • barn owls (Tyto alba)
  • Eurasian tawny owls (Strix aluco)
  • long-eared owls (Asio otus)
  • little owls (Athene noctua)
  • 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)
  • wild cats (Felis silvestris)
  • wild boars (Sus scrofa)

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. (Kryštufek, 2010)

• Ecosystem Impact
• 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). (Amori, et al., 2008; Myers and Poor, 2012)

• Positive Impacts
• 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). (Amori, et al., 2008; Mon­tec­chio, 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.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

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

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.