101. Occidental Gerbil Gerbillus occiduus French: Gerbille occidentale / German: Westliche Rennmaus / Spanish: Gerbillo occidental Taxonomy. Gerbillus occiduus Lay, 1975, 60 km WSW Goulimine, Aoreora, Morocco. Gerbillus occiduus was created as a new species on basis of morphological and cytogenetic characters. Its taxonomic validity was subsequently supported by S. Aulagnier and M. Thévenot in 1986 and by G. G. Musser and M. D. Carleton in 2005. A morphometric, cytogenetic and molecular analysis of Moroccan endemic gerbils in 2012 by A. Ndiaye and colleagues, who sequenced specimens from the type locality as well as from Boujdour, Dakhla, Tarfaya, and Tan Tan, confirmed validity of the species and found it to be close to G. tarabuli. Monotypic. Distribution. Coastal Morocco from 80 km WSW of Goulimine S of Anti-Atlas Mts to Tarfaya. Descriptive notes. Head—body 75-99 mm, tail 98-126 mm, ear 10-16 mm, hindfoot 28-31 mm. No specific data are available for body weight. The Occidental Gerbil is a small gerbil with hairy footsoles, cinnamon-buffy brown dorsal pelage, white ventral pelage, and long tail (115% of head-body length) terminating in small pencil of dark brown hairs. It has well-marked post-auricular and supraorbital white spots and dark eye-ring. Chromosomal complement has 2n = 40, FNa = 76. Habitat. Coastal sand dunes with poor vegetation and “sebkhas” (salt flats). Food and Feeding. No information. Breeding. Litter size is 1-5 (average 3-4). Activity patterns. The Occidental Gerbil is probably nocturnal and terrestrial, digging burrows. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Data Deficient on The IUCN Red List owing to recent captures of new specimens and extension ofits range (larger than previously known). There are, however, no specific protection measures for the Occidental Gerbil, which may be further threatened by development of tourism and coastal urbanization. Bibliography. Aulagnier & Thévenot (1986), Aulagnier et al. (2009), Happold (2013a), Lay (1975), Musser & Carleton (2005), Ndiaye etal. (2012).

Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Muridae, pp. 536-884 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 631, DOI: 10.5281/zenodo.6887260