Geographic Range
Japanese dormice are found on the Japanese islands of Honshuu, Shikoku, and Kyuushuu.
- Other Geographic Terms
- island endemic
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.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- scrub forest
- mountains
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.
- Other Physical Features
- endothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
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.
- Mating System
- polygynous
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
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.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
provisioning
- female
-
protecting
- female
-
provisioning
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.
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.
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.
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.
- Other Communication Modes
- duets
- scent marks
Food Habits
Japanese dormice are omnivorous, eating seeds, fruit, insects, and bird eggs. They
store food in their nesting areas for later use.
- Primary Diet
- omnivore
- Animal Foods
- eggs
- insects
- Plant Foods
- seeds, grains, and nuts
- fruit
- Foraging Behavior
- stores or caches food
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.
- 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.
- 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.
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
There are no known adverse effects of
Glirulus japonicus
on humans.
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.
Other Comments
Glirulus japonicus
is known in Japan as 'Yamane' (å±±é¼ ), or "mountain rat", and has long been an important
spiritual icon in the Shinto religion.
Additional Links
Contributors
Matthew Shaw (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon, Tanya Dewey (editor), Animal Diversity Web.
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- island endemic
-
animals that live only on an island or set of islands.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- 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.
- 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.
- 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.
- polygynous
-
having more than one female as a mate at one time
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- 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.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- 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.
- solitary
-
lives alone
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- 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
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- 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.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
References
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.
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 .