The white-tailed rat (''Mystromys albicaudatus'') also known as the white-tailed mouse, is the only member of the subfamily Mystromyinae in the family

Nesomyidae The Nesomyidae are a family (biology), family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are N ...

. This species is sometimes placed in the subfamily Cricetinae due to similarities in appearance between the white-tailed rat and

hamster Hamsters are rodents (order Rodentia) belonging to the subfamily Cricetinae, which contains 19 species classified in seven genera. They have become established as popular small pets. The best-known species of hamster is the golden or Syrian ...

s, but

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies have confirmed that the two groups are not closely related. The

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Mystromyinae is sometimes placed within the family

Muridae The Muridae, or murids, are either the largest or second-largest family of rodents and of mammals, containing approximately 870 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. ...

along with all other subfamilies of muroids. The white-tailed rat is restricted to shrubby areas and grasslands of

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and

Lesotho Lesotho, formally the Kingdom of Lesotho and formerly known as Basutoland, is a landlocked country in Southern Africa. Entirely surrounded by South Africa, it is the largest of only three sovereign enclave and exclave, enclaves in the world, t ...

. This is an uncommon species, and populations are thought to be declining because of conversion of scrubland to pasture. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has rated it as being an "

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

Description

The white-tailed rat is a fairly large species with a head-and-body length of for males and for females, with a short tail of about . The fur is soft, woolly and dense. The head is broad, and the face is mostly grey, with pale spots above the eye and behind the ear in some individuals. The whiskers are long and the ear is rounded and dark-coloured. The upper parts of head and body are greyish-brown flecked with buff; each hair has a grey base and shaft, and a buff or blackish tip. The underparts are whitish-grey, each individual hair having a grey base and shaft and a cream or whitish tip. The tail is colourless and is clad in short white fur. The fore feet have four digits and the hind feet five. The upper surfaces of the fore feet have white hair, as do the sides and upper surfaces of the hind feet.

Distribution and habitat

The white-tailed rat is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to South Africa and Lesotho where it is found in grasslands and shrubby areas. It tends to inhabit burrows of

meerkat The meerkat (''Suricata suricatta'') or suricate is a small mongoose found in southern Africa. It is characterised by a broad head, large eyes, a pointed snout, long legs, a thin tapering tail, and a brindled coat pattern. The head-and-body ...

s and cracks in the soil during the day and venture out at night. It eats vegetable matter such as seeds and has been known to take insects. The stomach has a ruminant-like digestive action and there are bacteria in the hind gut that ferment the food. Unlike

s, white-tailed rats do not have cheek pouches.

References

*Nowak, R. M. 1999. Walker's

Mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s of the World, Vol. 2. Johns Hopkins University Press, London. {{Taxonbar, from=Q74648 Nesomyid rodents Mammals described in 1834