63.

Fringe-tailed Gerbil

Gerbilliscus robustus

French: Gerbille robuste / German: Fransenschwanz-Nacktsohlenrennmaus / Spanish: Gerbillo de cola de cepillo

Taxonomy. Meriones robustus Cretzschmar, 1826,

Ambukol, Kordofan, Sudan.

Gerbilliscus robustus belongs to the East Afri-can clade and, according to the latest molecular study by L.. Granjon and colleagues in 2012, is very close to G. nigricaudus, G. vicinus, and G. phillipsi . It was previously confused with G. nigricaudus, which was considered a synonym of G. robustus, but P. J. J. Bates in 1988 regarded it as a valid species on account of its chromosomal and morphological characters. I. Ya. Pavlinov had shown in 1997 that G. robustus is morphometrically distinct from G. phillipsi and reorganized the synonymies within the species. G. robustus was considered a synonym of G. vicinus by G. G. Musser and M. D. Carleton in 2005, whereas P. Colangelo and colleagues have recently shown it to be distinct from latter both in molecular studies in 2005 and 2007 and in geometricmorphometric analyses in 2010. Monotypic.

Distribution. SE Niger and Chad E to Sudan, Eritrea, Ethiopia, and Somalia; it possibly also occurs in NE Nigeria, N Cameroon, and N Kenya.

Descriptive notes. Head-body 120-190 mm, tail 125-215 mm, ear 13-28 mm, hindfoot 21-40 mm; weight 80-152 g. The Fringe-tailed Gerbil is a large gerbil with dark brown dorsal pelage and pure white ventral pelage. Pelageis long and soft, with dorsal hairs (12-15 mm long) gray at their base. Dark soles of hindfeet are naked. Tail is long (c.115% of head—body length), is covered by thin hairs, and has a terminal dark pencil. Chromosomal complement has 2n = 40, FN = 70.

Habitat. Grassland savannas with Acacia (Fabaceae) bush and Salvadora (Salvadoraceae) thickets,at elevations of up to 1600 m. May be found in cultivated fields.

Food and Feeding. Fringe-tailed Gerbils are considered omnivorous.Its diet is composed of seeds in majority, with some arthropods, leaves and other plant material, and flowers. It is probably an opportunistic feeder with diet varying seasonality, as with other gerbils.

Breeding. Reproduction seems correlated with rainfall patterns. Females are pregnant Just after rains, and number of embryosis 2-7 (average 4-7).

Activity patterns. Fringe-tailed Gerbils are nocturnal and terrestrial. Burrows are deep (up to 60 cm below surface) and complex, with multiple tunnels; entrances are marked by spoil heaps, and burrow system may extend over large area (3 x 2 mj).

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Bates (1985, 1988), Colangelo, Castiglia et al. (2010), Colangelo, Corti et al. (2005), Colangelo, Granjon et al. (2007), Granjon et al. (2012), Happold (2013a), Hubert (1978b), Musser & Carleton (2005), Pavlinov (1997).