Jaculus jaculus
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
name: Thomas E. Lacher, Jr
Publisher: name: Lynx Edicions
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Dipodidae
Jaculus
Jaculus jaculus

description: 33.
Lesser Egyptian Jerboa
Jaculus jaculus
French: Gerboise du désert / German: Kleine Wistenspringmaus / Spanish: Jerbo pequeno de Egipto
Other common names: Lesser Jerboa
Taxonomy. Mus jaculus Linnaeus, 1758,
Giza Pyramids, Egypt.
In the past, J. hirtipes and J. loftusi were included in J. jaculus. Phylogenetically, J. jaculus is member of subgenus Jaculus, being the sister species of the J. hirtipes + |. loftusi clade. Seven subspecific names were proposed for J. jaculus in the African part of its distribution (part of which may really represent J. deserti) and one name in the Middle East. Subspecific taxonomy should be revised because previous analyses were based on mixed samples of J. hirtipes and Jjaculus. Molecular reconstructions retrieved two divergent allopatric lineages: one in North Africa and the other in Sinai Peninsula and Israel. Within the North African lineage, no significant spatial structuring and no significant relationship between geographical and genetic distances were found. Two subspecies recognized.
Subspecies and Distribution.
J. j. jaculus Linnaeus, 1758 — Morocco, Algeria, Tunisia, Libya, Egypt, Western Sahara, Mauritania, N Senegal, Mali, Niger, NE Nigeria, Chad, and Sudan.
J Jschlueter: Nehring, 1901 — NE Egypt (N Sinai Peninsula), Gaza Strip, and Israel; it probably occurs in adjacent extreme WJordan.
Descriptive notes. Head-body 119-130 mm, tail 191-197 mm, ear 19-22 mm, hindfoot 60-67 mm; weight 64-74 g. Head and dorsum ofthe Lesser Egyptian Jerboa vary from light sandy yellow to yellow-orange; sides and ventral pelage are pure white. Basal parts of vibrissae are white. Tail banner is wide and well flattened, with fuzzy white basal ring; black subterminalfield and white terminal tuft are about equalin length; and ventral side of black subterminal field is dissected by white stripe along tail rod. Toes of hindfeet are covered from below with brushes ofrelatively long soft hairs; hairs of brushes are white; and toes do not have conic calluses at bases. Rostral part of skull is slender. Auditory bullae are strongly inflated and project from under braincase laterally and caudally. Mastoid cavity is large and partially subdivided into three sections by septs. In volume, mastoid cavity is about three times larger than tympanic cavity. Front surfaces of incisors are white. P! is absent. Molars are high-crowned, with terraced masticatory surfaces; crown heights of unworn molars are 140-150% of their lengths. Glans penis is massive, cylindrical, elongated, subdivided by deep longitudinal folds into five lobes, one dorsal, two lateral and two ventral. Surfaces of lobes are covered by comb-like scales, with 2-6 (usually 3-4) long scallops at their proximal edges. Os penis (baculum) is large (its length about equal to length of glans penis) and straight, with relatively small flat horizontal broadening at proximal end and medium-sized flat horizontal broadenings at distal end. Chromosomal complement has 2n = 48 and FN = 96.
Habitat. Sand massifs preferring semi-stabilized sands with relatively sparse shrub vegetation; rarely loess and sandy-gravel desert.
Food and Feeding. The Lesser Egyptian Jerboa feeds on seeds, searching by sieving sand with forelimbs. It also eats leaves by climbing in shrubs.
Breeding. Litters of Lesser Egyptian Jerboas have 1-4 young. Gestation was estimated at 27 days. Young nursed for c.42 days.
Activity patterns. The Lesser Egyptian Jerboa is nocturnal. Hibernation has not been recorded.
Movements, Home range and Social organization. When moving slow, Lesser Egyptian Jerboas use bipedal pacing, with alternating support by left and right hindfeet; hops are 40-50 cm. At medium-speed and when running fast, they use asynchronous ricochetjumps; jumps are 80-100 cm. Winter burrows are placed on slopes of sand dunes and have 2-3 m of tunnels that are c.1 m deep.
Status and Conservation. Classified as Least Concern on The IUCN Red List.
Bibliography. Ben Faleh, Cosson et al. (2010), Ben Faleh, Granjon, Tatard, Boratynski et al. (2012), Boratynski, Brito, Campos et al. (2014), Boratynski, Brito & Mappes (2012), Granjon & Duplantier (2009), Happold (2013b), Kowalski & Rzebik-Kowalska (1991), Mendelssohn & Yom-Tov (1999), Osborn & Helmy (1980), Ranck (1968), Shahin & Ata (2001), Shenbrot et al. (2016).
description: Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Dipodidae, pp. 81-100 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 99, DOI: 10.5281/zenodo.6591722