93.

Lesser Egyptian Gerbil

Gerbillus gerbillus

French: Petite Gerbille / German: Kleine Agypten-Rennmaus / Spanish: Gerbillo de Egipto menor

Other common names: Lesser Gerbil, Small Egyptian Gerbil

Taxonomy. Dipus gerbillus Olivier, 1800,

Giza Province, Egypt .

Gerbillus gerbillus was originally described as a jerboa in genus Dipus, and later attrib-uted to genus Gerbillus by A. G. Desmarest in 1804. It has been quite well studied throughoutits large range and many syno-nyms are available, but G. G.Musser and M. D. Carleton in 2005 suggested the need for a taxonomic revision. A. Abiadh and colleagues in 2010 and A. Ndiaye and coworkers in 2016 confirmed the species’ validity on molecular grounds, though with no exploration of the different North African populations. Monotypic.

Distribution. N Africa, from Morocco and Mauritania to Egypt, N Sudan, N Djibouti, SW Israel, Palestine, and SW Jordan.

Descriptive notes. Head—body 70-105 mm, tail 90-136 mm, ear 10-18 mm, hindfoot 25-32 mm; weight 14-35 g. Slight sexual dimorphism observed in skull measurements. The Lesser Egyptian Gerbil is a medium-sized gerbil with hairy soles. Soft dorsal pelage is sandy to light orange in color, and ventral pelage is pure white. Some white spots are visible in auricular and supraorbital regions, and feet and hands are white. Tail is very long (135-145% of head—body length) and bicolored;it ends in a long pencil of whitish to dark gray hairs. Tympanic bullae are inflated in the mastoid portion. Mandible has a short coronoid process and a narrow ramus. Females bear four pairs of mammae. Different karyotypes are available, with 2n = 42/43 and a FNa = 72-74.

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Habitat. Sandy habitats in arid and semiarid regions. The Lesser Egyptian Gerbil has been captured in shifting sands in Mauritania, Egypt and Algeria. It has been reported also in “wadis” (ephemeral riverbeds) and oases, “sebkhas” (salt flats) with sparse vegetation cover, and palm groves.

Food and Feeding. The Lesser Egyptian Gerbil is primarily granivorous. Some plant material such as leaves, buds, and fruits of Thymelaea (Thymelaeaceae), Erodium (Geraniaceae), and Plantago spp. (Plantaginaceae), as well as some insects, may also complement the diet. It may store food reserves.

Breeding. Reproduction, which was studied in Mauritania, appears to take place throughout the year. Litter size is 3-6 young.

Activity patterns. The Lesser Egyptian Gerbil is nocturnal and terrestrial. It spends daytime in relatively deep burrows (30-80 cm) with tunnels (5-45 m in length) and 3—4 entrances that may be closed during the day. It is able to enter a state of hibernation or torpor in the laboratory.

Movements, Home range and Social organization. Home ranges are large (c. 100 m in diameter), and males especially explore wide areas when foraging. The Lesser Egyptian Gerbil has been reported at mean distance of 10-7 m between capture sites and a maximum distance of 105 m after four nights. An experimental study showed that 50% of the animals released at 500-1000 m from their burrow and 20% of those released at 2000 m were able to return to their home. In coastal Mauritania, the species can be common locally, reaching 0-2—4-8 ind/ha throughout the year.

Status and Conservation. Classified as Least Concern on The IUCN Red List owing to its abundance and large distribution.

Bibliography. Abiadh, Chétoui et al. (2010), Abiadh, Colangelo et al. (2010), Aulagnier et al. (2009), Bar et al. (1984), Cosson et al. (1997), Desmarest (1804), Granjon (2013e), Granjon & Duplantier (2009), Klein et al. (1975), Kowalski & Rzebik-Kowalska (1991), Lay et al. (1975), Mermod (1970), Musser & Carleton (2005), Ndiaye, Chevret et al. (2016), Ndiaye, Tatard et al. (2016), Osborn & Helmy (1980), Saint Girons & Petter (1965).