Glirulus japonicusJapanese dormouse

Ge­o­graphic Range

Japan­ese dormice are found on the Japan­ese is­lands of Hon­shuu, Shikoku, and Kyu­ushuu. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

Habi­tat

Japan­ese dormice live in a va­ri­ety of habi­tats. They are ar­bo­real and mostly found in de­cid­u­ous and conif­er­ous forests at medium to high el­e­va­tions, be­tween 400 and 1800 me­ters. Pop­u­la­tions of Japan­ese dormice have also been found in arid areas, moun­tains, and in lower el­e­va­tion, warm forests. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

  • Range elevation
    400 to 1800 m
    1312.34 to 5905.51 ft
  • Average elevation
    900 m
    2952.76 ft

Phys­i­cal De­scrip­tion

Japan­ese dormice are sim­i­lar in ap­pear­ance to both mice and squir­rels. They have a thick layer of soft, hazel or brown fur with a dark brown or black dor­sal stripe. They have tufts of hair on the an­te­rior side of the ears and the tail is bushy and flat­tened dor­sally. The hind­feet have four dig­its and the forefeet have five, all of which have short, hinged claws ac­com­pa­nied by soft pads that en­able them to swiftly run along the un­der­side of hang­ing tree limbs. Japan­ese dormice, like other dormice, hi­ber­nate dur­ing cold weather or times of lit­tle food. The sexes are alike, rang­ing in mass from 14 to 40 g and 105 to 135 mm head and body length. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; Nowak, 1999; Shi­bata and Kawamichi, 2006)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    14 to 40 g
    0.49 to 1.41 oz
  • Range length
    105 to 135 mm
    4.13 to 5.31 in

Re­pro­duc­tion

Japan­ese dormice are gen­er­ally soli­tary. In May, males emerge from hi­ber­na­tion to find a mate, re­ly­ing heav­ily on their well de­vel­oped abil­ity to vo­cal­ize. Fe­males re­spond to the vo­cal­iza­tions of males with their own calls. Males mate with sev­eral fe­males, as their home range often en­com­passes the home range of sev­eral fe­males. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

Japan­ese dormice mate in the late spring to early sum­mer. Ges­ta­tion lasts for about a month and an av­er­age of 4 young are born be­tween the months of June and July. Young are weaned after about 18 days, reach­ing in­de­pen­dence at around 4 to 6 weeks old. Sex­ual ma­tu­rity is at­tained at around 1 year. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

  • Breeding interval
    Japanese dormice breed actively in the spring and early summer
  • Breeding season
    Breeding occurs between the months of May and June.
  • Range number of offspring
    2 to 6
  • Range gestation period
    4 to 6 weeks
  • Range weaning age
    15 to 21 days
  • Range time to independence
    4 to 6 weeks
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Japan­ese dormice have rel­a­tively low parental in­vest­ment per off­spring be­cause of their large lit­ter sizes. Young are weaned at around 18 days and be­come com­pletely in­de­pen­dent be­tween 4 and 6 weeks old. Males have no in­volve­ment with their off­spring after cop­u­la­tion. Fe­males pro­vide all the care nec­es­sary to en­sure that their young sur­vive until in­de­pen­dence. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; Shi­bata and Kawamichi, 2006)

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

Lifes­pan/Longevity

Japan­ese dormice have an av­er­age life span in the wild of be­tween 3 and 5 years. The longest lifes­pan recorded for a Japan­ese dor­mouse is 6 years. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007)

  • Range lifespan
    Status: wild
    6 (high) years
  • Typical lifespan
    Status: wild
    3 to 5 years

Be­hav­ior

Japan­ese dormice are soli­tary, noc­tur­nal, and highly ar­bo­real, pos­sess­ing feet that are spe­cial­ized for cling­ing to the un­der­side of hang­ing branches and run­ning up­side down. They travel over a rel­a­tively large home range in search of food. Dormice are well know for their no­tably long hi­ber­na­tion pe­riod. In fact, the name "dor­mouse" comes from an ar­chaic An­glo-Nor­man word, "dormeus", mean­ing sleepy one. Japan­ese dormice are vocal dur­ing mat­ing sea­son. They weave in­tri­cate nests out of lichen and bark. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; Mac­Don­ald, 2006; Nowak, 1999; Shi­bata and Kawamichi, 2006)

Home Range

Male Japan­ese dormice travel over a much larger home range than do fe­males. How­ever, fe­males also travel over a home range size that is sur­pris­ingly large com­pared to other ro­dents of sim­i­lar size. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

Com­mu­ni­ca­tion and Per­cep­tion

Japan­ese dormice rely heav­ily on ol­fac­tion and mark their nests with urine in order to es­tab­lish ter­ri­tory. They use tac­tile cues ex­ten­sively when get­ting around their ar­bo­real habi­tats at night. When they emerge from hi­ber­na­tion in the spring, they pro­duce loud vo­cal­iza­tions that en­able them to lo­cate po­ten­tial mates. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009)

Food Habits

Japan­ese dormice are om­niv­o­rous, eat­ing seeds, fruit, in­sects, and bird eggs. They store food in their nest­ing areas for later use. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; Shi­bata and Kawamichi, 2006)

  • Animal Foods
  • eggs
  • insects
  • Plant Foods
  • seeds, grains, and nuts
  • fruit

Pre­da­tion

Lit­tle is known about preda­tors of Japan­ese dormice. They tend to live at low pop­u­la­tion den­si­ties and are not a re­li­able or abun­dant source of food for many po­ten­tial preda­tors. Their mod­i­fied sus­pen­sory lo­co­mo­tion and noc­tur­nal habits en­able them to move through forests rel­a­tively un­no­ticed. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007)

  • Anti-predator Adaptations
  • cryptic

Ecosys­tem Roles

Japan­ese dormice are im­por­tant in their na­tive ecosys­tems be­cause they eat large quan­ti­ties of in­sects, es­pe­cially dur­ing in­sect pop­u­la­tion out­breaks. Their role in dis­trib­ut­ing seeds of fruit­ing plants it also noted. Oth­er­wise, lit­tle is doc­u­mented con­cern­ing the eco­log­i­cal roles of this species. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007; "UNEP-WCMC", 2007; Mac­Don­ald, 2006; Nowak, 1999; Shi­bata and Kawamichi, 2006)

  • Ecosystem Impact
  • disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Japan­ese dormice are avid in­sect preda­tors and their pres­ence in ecosys­tems helps to con­trol pop­u­la­tions of in­sects. In Japan, agri­cul­ture is par­tic­u­larly vul­ner­a­ble to lo­custs, and Japan­ese dormice help con­trol sea­sonal swarms of such in­sects. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007; Mac­Don­ald, 2006)

  • Positive Impacts
  • controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Glir­u­lus japon­i­cus on hu­mans. ("Japan­ese Dor­mouse - Glir­u­lus japon­i­cus", 2009; "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007; "UNEP-WCMC", 2007; Mac­Don­ald, 2006; Nowak, 1999; Shi­bata and Kawamichi, 2006)

Con­ser­va­tion Sta­tus

The IUCN lists Glir­u­lus japon­i­cus as least con­cern. The Min­istry of Japan has des­ig­nated Japan­ese dormice as an en­dan­gered Na­tional Mon­u­ment and their habi­tats are under gov­ern­ment pro­tec­tion through­out Japan. ("Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007)

Other Com­ments

Glir­u­lus japon­i­cus is known in Japan as 'Ya­mane' (山鼠), or "moun­tain rat", and has long been an im­por­tant spir­i­tual icon in the Shinto re­li­gion. ("Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan", 2007)

Con­trib­u­tors

Matthew Shaw (au­thor), Uni­ver­sity of Ore­gon, Stephen Frost (ed­i­tor, in­struc­tor), Uni­ver­sity of Ore­gon, Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Glossary

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

duets

to jointly display, usually with sounds in a highly coordinated fashion, at the same time as one other individual of the same species, often a mate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Ref­er­ences

2009. "Japan­ese Dor­mouse - Glir­u­lus japon­i­cus" (On-line). Ac­cessed Jan­u­ary 21, 2009 at http://​www.​arkive.​org/​japanese-dormouse/​glirulus-japonicus/​.

2007. "Min­istry of the En­vi­ron­ment, Gov­ern­ment of Japan" (On-line). Ac­cessed Jan­u­ary 20, 2009 at http://​www.​env.​go.​jp/​en/​nature/​wh/​shirakami/​index.​html.

2007. "UNEP-WCMC" (On-line). Ac­cessed Jan­u­ary 20, 2009 at http://​www.​unep-wcmc.​org/​sites/​wh/​shira.​html.

Mac­Don­ald, D. 2006. The En­cy­clo­pe­dia of Mam­mals. Ox­ford: Ox­ford Uni­ver­sity Press.

Nowak, R. 1999. Walker's Mam­mals of the World, Sixth Edi­tion. Bal­ti­more and Lon­don: John Hop­kins Uni­ver­sity Press.

Shi­bata, F., T. Kawamichi. 2006. Daily rest-site se­lec­tion and use by the Japan­ese dor­mouse. Jour­nal of Mam­mal­ogy, 85: 30-37.