95.

Pygmy Gerbil

Gerbillus henleyi

French: Gerbille de Henley / German: Henley-Rennmaus / Spanish: Gerbillo pigmeo

Other common names: Henley's Gerbil, Henley's Pygmy Gerbil

Taxonomy. Dipodillus henley: de Winton, 1903,

Zaghig, Wadi Natrun, Egypt.

Taxonomic status of G. henleyi is not contested, despite lack of molecular data. Its morphological characters were revised by D. M. Lay in 1983 and by I. Ya. Pavlinov and colleagues in 1990. D. L. Harrison and P. J. J. Bates in 1991 accepted two different subspecies on geographical grounds. Two subspecies recognized.

Subspecies and Distribution G.h.henleyideWinton,1903—aridzonesofNAfrica(fromWesternSaharaandMoroccotoEgypt),andSoftheSaharafromSMauritaniaandNSenegaltoNSudan,withanisolatedrecordfromDjibouti.

G. h. mariae Bonhote, 1910 — Middle East (Sinai, S Israel, and Jordan) and scattered on Arabian Peninsula (Saudi Arabia, NE Qatar, N Yemen, andOman).

Descriptive notes. Head-body 55-73 mm, tail 73-107 mm, ear 8-11 mm, hindfoot 15-8-20 mm; weight 8-14 g. The Pygmy Gerbil is a very small gerbil with naked hindfoot soles. Dorsum is dark brownish gray, venter white, and well-defined white supraorbital and post-auricular spots are present. There is a black line on eyelids. Tail is long (130% of head—body length) and ends in thin dark gray pencil of hairs. Mandible and molar rows are very small. Chromosomal complement is 2n = 52 and FNa = 58-62.

Habitat. Arid environments, including sand dunes, saline marshes with halophytes, dry riverbeds, and gravel plains.

Food and Feeding. The Pygmy Gerbil mainly feeds on seeds.

Breeding. Different studies reported 3-6 embryos per pregnant female and possible seasonality of reproduction.

Activity patterns. The Pygmy Gerbil is nocturnal and terrestrial. It digs simple burrows below surface, with a small entrance (10-20 mm diameter) closed during the day.

Movements, Home range and Social organization. In Israel, population density averaged 0-9-2-3 ind/ha (range 0-5-5 ind/ha). Recaptures of Pygmy Gerbils are rare, which may indicate that the species has no territory and is very mobile.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Pygmy Gerbil may be abundant locally and has a large range. Because it is found in arid environments it seems not to be under any threats.

Bibliography. Abu Baker & Yamaguchi (2017), Aulagnier et al. (2009), Granjon (2013f), Granjon & Duplantier (2009), Harrison & Bates (1991), Lay (1983), Lay et al. (1975), Maddalena et al. (1988), Pavlinov et al. (1990), Pearch et al. (2001), Shenbrot et al. (1994), Volobouev et al. (1995), Wassif et al. (1969).