59.

Sahelo-Sudanian Gerbil

Gerbilliscus gambianus

French: Gerbille de Gambie / German: Gambia-Nacktsohlenrennmaus / Spanish: Gerbillo de Sahel de Sudan

Other common names: Gambian Gerbil

Taxonomy. Tatera gambiana Thomas, 1910,

“Marakissa, [Gambia]; alt. 500”

[= 152 m].”

Initially synonymized with G. kempii or G. validus by some authors, G. gambianus was restored to full species status by R. Matthey and F. Petter in 1970 on basis of chromosomal study, an opinion followed by B. Hubert and coworkers in 1973 and D. C. D. Happold in 2013. New chromosomal and molecular studies by V. T. Volobouev and colleagues and by P. Colangelo and team, both in 2007, and by L. Granjon and coworkers in 2012 confirmed its validity. Monotypic.

Distribution. Sahelo-Sudanian savannas in W & S Senegal, SW Mali, SE Niger, and extreme WC Chad.

Descriptive notes. Head-body 125-196 mm, tail 130-175 mm, ear 17-23 mm, hindfoot 27-34 mm; weight 61-193 g. The Sahelo-Sudanian Gerbil, a large gerbil, has a gray-brown dorsal pelage and a white belly. Hindfeet are bicolored, asis the tail, which is relatively short (80-105% of head-body length) and has no terminal tuft. Females bear four pairs of mammae. Chromosomal complement has 2n = 52, FNa = 64.

Habitat. The Sahelo-Sudanian Gerbil inhabits sandy soils in dry Combretum (Combretaceae) woodland and bushland savanna, as well as fallow lands and cultivated fields. It is found in mangrove sandy islands of the Saloum Delta in Senegal .

Food and Feeding. Sahelo-Sudanian Gerbils are herbivorous, granivorous, and sometimes add insects to their diet.

Breeding. After 25 days of gestation, female Sahelo-Sudanian Gerbils give birth to 2-6 offspring.

Activity patterns. The Sahelo-Sudanian Gerbil is nocturnal and terrestrial. It digs burrows at ¢.30 cm beneath the soil and with many entrances.

Movements, Home range and Social organization. Home ranges of Sahelo-Sudanian Gerbils vary between 600 m? and 800 m* and the species does not move far from its territory. Males’ and females’ home ranges overlap. Up to 20 burrows can be found in the home range of an individual. Locally, abundance varies with habitat, from 15 ind/ha in woodland to 24 ind/ha in the Saloum Delta region.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as G. gambiana) as a result of its abundance.

Bibliography. Colangelo et al. (2007), Dobigny, Nomao & Gautun (2002), Granjon & Duplantier (2009), Granjon et al. (2012), Happold (2013a), Hubert et al. (1973), Matthey & Petter (1970), Volobouev, Aniskin et al. (2007).