Anderson's gerbil (Gerbillus andersoni)
|Size||Length: 19 - 27 cm (2)|
Tail length: 11 - 15 cm (2)
|Weight||15.9 - 38.4 g (2)|
Classified as Least Concern (LC) on the IUCN Red List (1).
The little-known Anderson’s gerbil is a relatively slender-built, medium-sized gerbil. It has fairly long, dense fur, which is dark tan with some orange and red tints on the upperparts, and white on the underside. It has large, prominent ears which are dark in colour (3), and is distinguishable from other species of the Gerbillus genus due to a less distinct white patch behind the ear (2). As is typical of Gerbillus species, Anderson’s gerbil possesses large eyes, which are encircled by a thin, black ring. A relatively indistinct white patch sits above each eye, and a fairly thick, dark band stretches from the eyes to the ears (2). As is characteristic of Gerbillus species, this gerbil has long hind legs and short front legs (4).
Anderson’s gerbil is similar to the lesser Egyptian gerbil (Gerbillus gerbillus) in both size and the fact that it is a ‘hairy-footed’ gerbil, meaning the soles of its feet are completely haired; it is for these similarities that early taxonomists classified Anderson’s gerbil as a subspecies of the lesser Egyptian gerbil (3). However, the two are distinguishable by many traits, including the fact that Anderson’s gerbilhas darker fur and smaller ears than G. gerbillus (5).
Anderson’s gerbil is distributed from North Africa to the Middle East, from Tunisia, through Libya, Egypt and Israel to Jordan (1).
In coastal areas, Anderson’s gerbiltends to occupy sandy coastal dunes (6), and has been found to be associated with solidified coastal dunes (1). When found in inland areas it tends to inhabit sandy areas in wadis (valleys or dry streambeds) and mountainsides (7) (8).
Gerbillus species are burrowing rodents, but build less sophisticated warrens than other gerbil genera, which could suggest a more nomadic existence or may be due to physical limitations of the areas that Gerbillus species inhabit (4). These gerbils are sometimes gregarious, living in groups in favourable areas of habitat (4). It has been found that Anderson’s gerbiloccupies a small home range, typically covering 32 to 34 square metres, which contains both burrows and feeding areas (9).
Anderson’s gerbil is a nocturnal, seed-eating species (8) (9), which feeds primarily on the seeds of the common evergreen shrub species Thymelea hirsuta (10), and aggressively defends suitable foraging patches (11).
The breeding season for Anderson’s gerbilbegins in late winter or early spring, coinciding with the annual seed shedding of its favoured food Thymelea hirsuta (10). Both males and females of the species are reproductively active once a year (10), with the female giving birth to a litter of three to seven offspring (5) after a gestation period of 20 to 22 days (12). Anderson’s gerbil is able to reproduce in the breeding season the year after it is born, and it has been suggested that most adults die after the end of their first breeding season (10).
At present, no major threats to Anderson’s gerbil are known, although it has been suggested that overgrazing may be a concern in some parts of its range (1), as its burrows could be damaged by trampling agricultural animals. Habitat loss is undoubtedly the most significant threat to small mammals, particularly to those which have very specific habitat requirements, such as Anderson’s gerbil.
As Anderson’s gerbilis not currently considered to be at risk of extinction, there are no known conservation measures currently in place for this species (1).
Checked (24/08/10) by Dr Francis Gilbert, Associate Professor, University of Nottingham.
- Genus: (plural genera) a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a species scientific name; the second part is the specific name.
- Gestation: the state of being pregnant; the period from conception to birth.
- Home range: the area occupied by an animal during routine activities, which is not actively defended.
- Nocturnal: active at night.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
IUCN Red List (April, 2010)
- Kingdom, J. (1977) East African Mammals. Academic Press, London.
CITES (April, 2010)
- Koehler, C.E. and Richardson, P.R.K. (1990) Proteles cristatus. Mammalian Species, 363: 1-6.
- Richardson, P.R.K. and Bearder, S.K. (1984) The aardwolf. In: Macdonald, D.W. (Ed.) The Encyclopedia of Mammals. Allen G and Unwin, London.
- Meester, J.A.J., Rautenback, N.J., Dippenaar, N.J. and Baker, C.M. (1986) Classification of southern African mammals. Transvall Museum Monographs, 5: 1-359.
- Skinner, J.D. and Chimimba, C.T. (2005) The Mammals of the Southern African Subregion. Cambridge University Press, Cambridge.
- Smithers, R.H.N. (1971) The Mammals of Botswana. Museum Memoir No. 4, National Museums of Rhodesia, Salisbury.
- Richardson, P.R.K. (1987) Food consumption and seasonal variation in the diet of the aardwolf Proteles cristatus in southern Africa. Zeitschrift fur Saugetierkunde, 52: 307-325.