Mystromyinaewhite-tailed mouse

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Diversity

Mystromyinae is an Old World nesomyid subfamily that has a single genus and species, the white-tailed mouse (Mystromys albicaudatus). (Musser and Carleton, 2005)

Geographic Range

Mystromys albicaudatus is found in South Africa and Swaziland. (Nowak, 1999)

Habitat

These rodents inhabit dry savannahs and semidesert. (Nowak, 1999)

Physical Description

White-tailed mice are rat-like in overall appearance, with slender limbs and large, prominent ears. Their long, soft fur ranges from brown to buffy-gray on the dorsal surface, with interspersed black-tipped hairs. The ventral surface, feet, and tail are white, and the ears are dark brown. The tail is covered with stiff, short hairs. The head and body length of white-tailed mice ranges from 105 to 184 mm, and the tail length ranges from 50 to 97 mm. They weigh 75 to 111 grams, males tend to be about 20 grams heavier than females (Becker and Middleton 1979). The incisors of mystromyines are pale yellow and the surfaces lack grooves. Mystromyines have no cheek pouches, and they have two pairs of inguinal mammae. (Becker and Middleton, 1979; Nowak, 1999)

  • Sexual Dimorphism
  • male larger

Reproduction

The mating system of white-tailed mice has not been studied in the wild; however, in captivity, white-tailed mice form monogamous pairs that share in the task of raising offspring. (Hallett and Meester, 1971)

Mystromyines breed year-round. Females give birth to an average of three young per litter, after a gestation of about 37 days. The young are altricial; they are born hairless, with their eyes and ears sealed shut, and with their toes fused together. Their ears open after three to four days, and their incisors erupt at about the same time. Their toes separate between 9 and 11 days after birth, and their eyes open at 16 to 20 days. The young can crawl with difficulty at birth, becoming more accomplished by the time they are five to six days old. They can walk by day 20 and run by day 24. The young groom themselves at day 21, and begin eating solid food at day 20. By day 38, the young are completely weaned. Females attain sexual maturity at about five months. (DeGraaff, 1997; Hallett and Meester, 1971; Nowak, 1999)

Young white-tailed mice cling to the nipples of their mother almost continuously for the first three weeks of life. She drags them around with her when she forages. After three weeks, they separate from her for longer and longer periods, and she stops nursing them after another two and a half weeks. Females groom their young, especially after a disturbance. Both males and females carry their young immediately after parturition and protect their young by sheltering them with their bodies and trying to bite intruders. (Hallett and Meester, 1971; Nowak, 1999)

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

Lifespan/Longevity

White-tailed mice live to about six years in captivity; lifespan in the wild has not been reported. (Nowak, 1999)

Behavior

White-tailed mice are nocturnal, strictly terrestrial rodents that rest by day in holes or cracks in the ground. Sometimes they shelter in meerkat burrows. They are reportedly most active when it rains. (Hallett and Meester, 1971; Nowak, 1999)

Communication and Perception

White-tailed mice probably have keen olfactory and auditory abilities, as they have been observed rearing up on their hind legs and sniffing when disturbed. Young mystromyines probably have good senses of smell and touch from birth. They squeal when they are separated from their parents and begin responding to sound at 13 to 15 days of age. (Hallett and Meester, 1971)

Food Habits

Mystromyines eat insects, seeds, and other plant matter. In captivity, they will eat meat and carrots. Adults have also been observed eating the carcasses of dead offspring. (Hallett and Meester, 1971; Nowak, 1999)

Predation

Barn owls (Tyto alba) are reported predators of white-tailed mice. Other likely predators include other owl species, snakes, and nocturnal mammalian predators Young white-tailed mice cling to the nipples of their mothers continuously for the first few weeks of life, which increases their chance of survival because adult females can more easily evade predators than can immobile neonates. Even after they are no longer nursing constantly, youngsters seek shelter under their parents when alarmed. Parents sometimes defend their offspring by biting viciously. (DeGraaff, 1997; Hallett and Meester, 1971)

Ecosystem Roles

Because they are omnivores, mystromyines are primary and higher-level consumers. They are also food for animals at higher trophic levels, such as barn owls. (DeGraaff, 1997)

Economic Importance for Humans: Positive

White-tailed mice are easy to breed in captivity and are therefore used in laboratories for disease research. (Hallett and Meester, 1971)

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

There are no known negative effects of white-tailed mice on humans.

Conservation Status

White-tailed mice are currently considered endangered by the IUCN; though their range is relatively large, population density is low and populations are highly fragmented. There are protected areas in some parts of the species' range, but habitat loss to grazing, agriculture, and timber plantations is a major threat. Surveys of white-tailed mouse populations and research into their life history characteristics are needed, as is public awareness about their plight. (Coetzee and Monadjem, 2004)

  • IUCN Red List [Link]
    Not Evaluated

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Allison Poor (author), 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

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.

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

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.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

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).

monogamous

Having one mate at a time.

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

scavenger

an animal that mainly eats dead animals

sexual

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

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.

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.

year-round breeding

breeding takes place throughout the year

References

Becker, S., C. Middleton. 1979. Organ weights and organ body weight ratios of the African white-tailed rat (Mystromys albicaudatus). Laboratory Animal Science, 29(1): 44-47.

Carleton, M., G. Musser. 1984. Muroid rodents. Pp. 289-379 in S Anderson, J Jones Jr., eds. Orders and Families of Recent Mammals of the World. New York: John Wiley and Sons.

Coetzee, N., A. Monadjem. 2004. "Mystromys albicaudatus" (On-line). 2004 IUCN Red List of Threatened Species. Accessed July 05, 2005 at www.redlist.org.

DeGraaff, G. 1997. White-tailed rat Mystromys albicaudatus. Pp. 156 in G Mills, L Hes, eds. The Complete Book of Southern African Mammals. Cape Town: Struik Publishers.

Ellerman, J. 1941. The Families and Genera of Living Rodents, vol. II. London: British Museum (Natural History).

Hallett, A., J. Meester. 1971. Early postnatal development of the South African hamster Mystromys albicaudatus. Zoologica Africana, 6(2): 221-228.

Jansa, S., M. Weksler. 2004. Phylogeny of muroid rodents: relationships within and among major lineages as determined by IRBP gene sequences. Molecular Phylogenetics and Evolution, 31: 256-276.

Lavocat, R. 1973. Les rongeurs du Miocene d'Afrique Orientale. Memoires et Travaux de l'Ecole Pratique des Hautes Etudes, Institut de Montpellier, 1: 1-284.

Michaux, J., A. Reyes, F. Catzeflis. 2001. Evolutionary history of the most speciose mammals: molecular phylogeny of muroid rodents. Molecular Biology and Evolution, 18(11): 2017-2031.

Musser, G., M. Carleton. 1993. Family Muridae. Pp. 501-573 in D Wilson, D Reeder, eds. Mammal Species of the World. Washington, D.C.: Smithsonian Institution Press.

Musser, G., M. Carleton. 2005. Superfamily Muroidea. D Wilson, D Reeder, eds. Mammal Species of the World. Baltimore and London: The Johns Hopkins University Press.

Nowak, R. 1999. Walker's Mammals of the World, vol. II. Baltimore and London: The Johns Hopkins University Press.

Skinner, J., R. Smithers. 1990. The mammals of the southern African subregion. Republic of South Africa: University of Pretoria.

Vorontsov, N. 1966. Taxonomic position and a survey of the hamsters of the genus Mystromys Wagn. (Mammalia, Glires). Zoologicheskii Zhurnal, 45: 436-446.