Graphiurus murinuswoodland dormouse

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Geographic Range

Woodland dormice occur throughout Ethiopian region. They are widely distributed throughout Africa, from the southern edge of the Sahara Desert to Cape Province, South Africa. (Skinner and Chimimba, 2005; Webb and Skinner, 1994)

Habitat

Woodland dormice are generalists and can be found in a broad range of habitats. Although they commonly nest in Acacia trees, their nests can also be found in tree hollows, rock crevices, on tree branches, in shrubs and even in abandoned bird nests and bee hives. (Fitzherbert, et al., 2006; Skinner and Chimimba, 2005; Webb and Skinner, 1994)

Physical Description

Woodland dormice are one of the larger African dormice species, ranging from 70 to 165 mm in head and body length and from 50 to 135 mm in tail length. They are squirrel-like in appearance, with dorsal pelage that ranges from light to dark gray and ventral pelage that is buffy white. They have short, soft wooly hair and a long bushy tail. A ring of darker fur often encircles their black eyes, and their ears range in length (a commonly used metric for species identification in mice) from 10 to 20 mm. They have short curved claws and their hind feet range in length from 15 to 20 mm. Woodland dormice range in mass from 23 to 34 g and are often confused with savannah dormice, which are detectably smaller. Their braincase is moderately cuboidal and domed, with slightly enlarged auditory bullae. (Grizmek, 2004; Haberl, 1999; Skinner and Chimimba, 2005; Webb and Skinner, 1994)

  • Range mass
    23 to 34 g
    0.81 to 1.20 oz
  • Range length
    70 to 165 mm
    2.76 to 6.50 in

Reproduction

Limited information is available on the mating system of woodland dormice. At the onset of breeding season, however, males are very territorial and aggressive towards one another, suggesting polygyny. Once they emerge from their hibernacula, many species of dormice call out to alert potential mates of their presence. Once mated, males are likely to leave prior mates to search for additional estrous females. (Grizmek, 2004; Webb and Skinner, 1994)

Although most breeding occurs during the summer (October through February), woodland dormice commonly breed throughout the year (i.e., seasonal polyestry). Females have 1 to 2 litters per year. Gestation is thought to last for approximately 24 days, resulting in 3 to 4 altricial pups per litter; however, as many as 6 pups per litter may be possible. Pups weigh approximately 3.5 g at birth, and they are not reproductively mature until the summer after their first hibernation. (Grizmek, 2004; Haberl, 1999; Webb and Skinner, 1994)

  • Breeding interval
    Woodland dormice can breed twice during the summer
  • Breeding season
    Breeding typically occurs from October to February.
  • Range number of offspring
    3 to 4
  • Average gestation period
    24 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

Little information is available on the parental investments of woodland dormice. However, newborns are altricial and independence from the mother most likely occurs between 4 and 6 weeks of age. Mothers provide protection, grooming, and nourishment (e.g., nursing) until pups reach independence. Pups are cared for in nests lined with moss, which are often found in tree hollows, rock crevices, on tree branches, in shrubs and even in abandoned bird nests and bee hives. Detailed information on paternal investment has not been reported. (Grizmek, 2004; Haberl, 1999; Webb and Skinner, 1994; Wirminghaus and Perrin, 1993)

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

Lifespan/Longevity

Woodland dormice live for approximately 5.5 years in the wild and may live 5 to 6 years in captivity. (Grizmek, 2004; Haberl, 1999)

  • Average lifespan
    Status: wild
    5.5 years
  • Average lifespan
    Status: captivity
    5.9 years

Behavior

Woodland dormice are nocturnal and highly arboreal. They forage alone at night, mostly for insects and vegetation. In the fall, woodland dormice increase fat reserves by eating nuts and seeds prior to hibernating. During winter (May to August), when temperatures drop considerably, woodland dormice hibernate. During hibernation, they experience significant decreases in body temperature and mass. Their thermal neutral zone is between 29 and 35 °C, and they begin hibernating at an ambient temperature of about 15 °C. In the summer, woodland dormice may enter torpor during periods of decreased food abundance or when low or erratic temperatures occur. Woodland dormice are unique within their genus (Graphiurus), as they are the only African dormouse species to hibernate during the winter. (Ellison and Skinner, 1991; Webb and Skinner, 1996; Whittington-Jones and Brown, 1999)

During periods of inactivity, African dormice spend time in their nests, which are typically made of plant material and found in tree cavities, shrubs, and rock crevices. To prevent heat loss, they curl themselves into a ball and wrap their tails around their bodies. Males, females, and juveniles may occupy an individual nest, and as many as 11 adults, consisting of both genders, have been found to occupy a single nest. African dormice use nests year round; however, nest type changes in relation to season. During the winter, they use nests that are better insulated and closer to the ground, than those used during the summer. (Grizmek, 2004; Haberl, 1999; Madikiza, et al., 2010; Skinner and Chimimba, 2005; Webb and Skinner, 1994)

Males are territorial during the breeding season and establish a social hierarchy once they emerge from hibernation. Males scent mark and make warning vocalizations to demarcate and defend nesting territories, respectively. Although females scent mark territorial boundaries, they do not make warning vocalizations to ward off members of opposing groups. (Grizmek, 2004; Haberl, 1999; Madikiza, et al., 2010; Skinner and Chimimba, 2005; Webb and Skinner, 1994)

Home Range

Although little information is available on the size and composition of woodland dormice home ranges, its close relative, the spectacled dormouse (Graphiurus ocularis), has an average home-range size of 13.9 ha for males and 8.5 ha for females. Generally, there are about 10 woodland dormice per ha. ("International Union for Conservation of Nature and Natural Resources (IUCN)", 2010; Grizmek, 2004)

Communication and Perception

Woodland dormice make a variety of vocalizations including mating calls, territorial calls, alarm squeaks, and twittering sounds, for which the meaning is unknown. In addition, woodland dormice are likely to use visual, haptic (e.g., sense of touch), and olfactory cues to communicate with one another. Scent marking is likely used to establish territories and find mates, whereas vocalizations are probably used to find and defend mates, and defend territories. (Grizmek, 2004; Haberl, 1999; Webb and Skinner, 1994)

Food Habits

Woodland dormice are omnivores, with dietary composition changing in relation to season. During spring, they eat primarily buds and insects, but occasionally eat small rodents and the eggs and young of small birds. In summer and fall, they eat fruit, seeds, and nuts to increase fat reserves for hibernation, and when food abundance is low, they may also eat bark and twigs. (Grizmek, 2004; Nowakowski, et al., 2006; Webb and Skinner, 1994; Wirminghaus and Perrin, 1992)

  • Animal Foods
  • birds
  • reptiles
  • eggs
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit

Predation

Woodland dormice are preyed upon mostly by owls, and their remains have been found in the pellets of Mackinder's eagle owl (Bubo capensis mackinderi) in East Africa. Because they are both arboreal and nocturnal, woodland dormice have few predators. (Rodel, et al., 2002)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Woodland dormice may play a role in the population dynamics of arthropods, which constitutes a significant proportion of their diet. Because they forage on various types of fruits and nuts, they may also be important seed dispersers. Finally, they are an important prey species for owls. (Haberl, 1999; Nowakowski, et al., 2006)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

African dormice have no documented economic effect on humans. However, due to their high fat content, they are a preferred source of protein in some cultures. Human consumption of dormice is a well documented global phenomenon. (Grizmek, 2004)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Woodland dormice are sometimes thought of as nuisances, as they occasionally make their nests in old furniture, roofs, electrical switch boxes, water pumps, and transformers. They can cause agricultural damage by raiding poultry farms and foraging on crops. (Grizmek, 2004; Haberl, 1999; Skinner and Chimimba, 2005)

Woodland dormice are potential vectors for bubonic plague and monkeypox. A 2007 study in northern Tanzania found woodland dormice that were positive for Yersinia pestis, the bacterium that causes plague. (Holden and Levine, 2009; Makundi, 2008)

  • Negative Impacts
  • injures humans
    • carries human disease
  • crop pest
  • household pest

Conservation Status

Woodland dormice exhibit stable population trends and currently, there are no major threats to this species. The IUCN lists woodland dormice as a species of "least concern". ("International Union for Conservation of Nature and Natural Resources (IUCN)", 2010)

Contributors

Jeanna Lodel (author), University of Wisconsin-Stevens Point, Stefanie Stainton (editor), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, John Berini (editor), Animal Diversity Web Staff, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

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.

carnivore

an animal that mainly eats meat

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.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

forest

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

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

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.

insectivore

An animal that eats mainly insects or spiders.

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.

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

polygynous

having more than one female as a mate at one time

scent marks

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

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

social

associates with others of its species; forms social groups.

solitary

lives alone

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.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

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

2010. "International Union for Conservation of Nature and Natural Resources (IUCN)" (On-line). The IUCN Red List of Threatened Species (On-line). Accessed July 27, 2010 at htpp://www.iucnredlist.org/search.

Ellison, G., J. Skinner. 1991. Thermoregulation and torpor in African woodland dormice, Graphiurus murinus, following cold acclimation. Zeitschrift fu¨r Sa¨ugetierkunde, 56/1: "41-47".

Fitzherbert, E., T. Gardner, T. Caro, P. Jenkins. 2006. Habitat preferences of small mammals in the Katavi ecosystem of western Tanzania. African Journal of Ecology, 45: "249-257".

Grizmek, B. 2004. Grizmek's Encyclopedia of Mammals. Farmington Hills, MI: Gale Group In..

Haberl, W. 1999. "The Dormouse Hollow: Graphiurus" (On-line). The Dormouse Hollow. Accessed July 30, 2010 at http://www.gliratium.org/dormouse.

Holden, M., R. Levine. 2009. Systematic revision of Sub-Saharan African dormice (Rodentia:Gliridae: Graphiurus) Part ll: Description of a new speices of Graphiurus from the Central Congo Basin, including morphological and ecological niche comparisons with G. crassicaudatus and G. lorraineus. Bulletin of the American Museum of Natural History, 331: "314-355".

Madikiza, Z., S. Bertolino, R. Baxter, E. San. 2010. Nest box use by woodland dormice (Graphiurus murinus): the influence of life cycle and nest box placement. European Journal of Wildlife Research, 56: 1-10.

Makundi, R. 2008. Potential mammalian reservoirs in a bubonic plague outbreak focus in Mbulu District, northern Tanzania, in 2007. Mammalia: journal de morphologie, biologie, systematique des mammiferes, 72/3: "253".

Nowakowski, W., M. Remisiewicz, J. Kosowska. 2006. Food preferences of Glis glis (L.), Dryomys nitedula (Pallas), and Graphiurus murinus (Smuts) kept in captivity. Polish Journal of Ecology, 54/3: "369-378".

Rodel, H., W. Scholze, D. Kock. 2002. Diet of Mackinder's eagle owl Bubo capensis mackinderi in the alpine zone of Mount Kenya. African Journal of Ecology, 40: "283-288".

Skinner, J., C. Chimimba. 2005. The mammals of the southern African subregion, 3rd edn. Cambridge: Cambridge University Press.

Webb, P., J. Skinner. 1996. Summer torpor in African woodland dormice Graphiurus murinus (Myoxidae: Graphiurinae). Journal of Comparative Physiology, 166/5: "325-330".

Webb, P., J. Skinner. 1994. The Dormice (Myoxidae) of southern Africa. Hystrix, The Itialian Journal of Mammology, 6: "287-293".

Whittington-Jones, C., C. Brown. 1999. Thermoregulatory capabilities of the Woodland dormouse, Graphiurus murinus. South African Journal of Zoology, 34: "34-38".

Wirminghaus, C., M. Perrin. 1993. Seasonal changes in density, demography, and body composition of small mammals in a southern temperate forest. Journal of Zoology, 229: "303-318".

Wirminghaus, J., M. Perrin. 1992. Diets of small mammals in a southern African temperate forest. Israel Journal of Zoology, 38: "353-361".