136.

Fat-tailed Jird

Pachyuromys duprasi

French: Gerbille de Dupras / German: Fettschwanz-Rennmaus / Spanish: Gerbillo de cola gruesa

Other common names: Fat-tailed Gerbil

Taxonomy. Pachyuromys duprasi Lataste, 1880,

Laghouat, Algeria.

Monotypic genus Pachyuromys is characterized by morphological, chromosomal, and molecular characters. It seems to be one of the basal members of Gerbillini tribe, and was placed in subtribe Pachyuromina by I. Ya. Pavlinov and colleagues in 1990 and again in 2008, by G. G.Musser and M. D. Carleton in 2005, and by P. Chevret and G. Dobigny also in 2005. Monotypic.

Distribution. Arid regions of Morocco, Western Sahara, N Mauritania, Algeria, N Mali, Tunisia, Libya, and Egypt.

Descriptive notes. Head—body 93-120 mm, tail 55-65 mm, ear 12-16 mm, hindfoot 22-24 mm; weight 22-65 g. The Fat-tailed Jird has appearance of a middle-sized gerbil with sandy-yellow to gray dorsal pelage and a white belly, but has short limbs and short tail (tail 50-55% of head-body length). Tail is pink, thick, and naked. White patches of hair are found on chin, throat, lips, and muzzle, the hairs long and shaggy. Skull is characterized by a very large braincase and inflated tympanic bullae (latter c.47% of maximum length of skull). Chromosomal complement has 2n = 54, FNa = 62.

Habitat. Semiarid to very arid regions on high plateau and the Sahara. The Fat-tailed Jird prefers hard soils of “hamadas” (barren, hard, rocky plateaus) and rocky areas, as well as compact sandy areas where sparse vegetation is present. Coarse pebbles and large boulders are also used where vegetation is scarce.

Food and Feeding. The Fat-tailed Jird is a largely granivorous species feeding on Colocynthis vulgaris ( Cucurbitaceae) seeds and fruits and also those of henbane ( Hyoscyamus niger, Solanaceae), but it also consumes succulent plants and insects. In Egypt this jird was seen also to eat Anabasis articulata ( Amaranthaceae) and Artemisia monosperma (Asteraceae) . In captivity, it is omnivorous. In captivity, it has been observed that the tail of these rodents changes in size and thickness according to season ofyear and the amount of stored fat. When temperature is reduced experimentally, Fat-tailed Jirds are able to enter torpor for several days.

Breeding. Reproduction may be activated by food containing meat. Gestation period is 21 days andlitter size is 2—4 young. Young are blind and naked at birth; they open eyes at eight days, are weaned at 20-21 days, and reach adult size at ten weeks.

Activity patterns. The Fat-tailed Jird is crepuscular, and both nocturnal and terrestrial. It is able to dig burrows of various complexity and extent. Burrows have been reported to have 3-12 entrances and to occupy 9-20 m?, but in general they are shallow and situated 5-30 cm below surface. They contain a nest in which the jirds store food. Burrows are generally situated on slopes of sand dunes compacted by rainstorms.

Movements, Home range and Social organization. Fat-tailed Jirds have a great capacity to return to their home base (up to 2 km). There are no studies on their social organization, but P. Bridelance in 1989 showed that they exchange a low variety of vocalizations and that male calls differ from those of females. They may be aggressive in captivity.

Status and Conservation. Classified as Least Concern on The IUCN Red List owing to its large distribution and absence of threats throughout its range. Fat-tailed Jirds are rarely captured by trapping, however, and most of what is known about this species comes from owl-pellet data. Fat-tailed Jird is quite easy to keep in captivity and has been used as a model in physiology studies.

Bibliography. Aulagnier & Thévenot (1986), Aulagnier et al. (2009), Benazzou et al. (1984), Bridelance (1989), Chevret & Dobigny (2005), Daly & Daly (1979), Granjon & Duplantier (2009), Happold (2013a), Heim de Balsac (1965), Kowalski & Rzebik-Kowalska (1991), Mermod (1970), Musser & Carleton (2005), Osborn & Helmy (1980), Padial & Ibanez (2005), Pavlinov (2008), Pavlinov etal. (1990), Petter (1961c¢), Poulet (1974).