Salpingotus pallidus, Vorontsov & Shenbrot, 1984

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Dipodidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 81-100 : 84

5.

Pallid Pygmy Jerboa

Salpingotus pallidus

French: Gerboise pale / German: Blasse Dreizehenzwergspringmaus / Spanish: Jerbo pigmeo palido

Other common names: Pale Pygmy Jerboa; Pale Pygmy Aral Jerboa (pallidus), Pale Pygmy Balkhash Jerboa (s/ udskii)

Taxonomy. Salpingotus pallidus Vorontsov & Shenbrot, 1984 ,

Bolshyye Barsuki Sands near Chelkar , Aktybinsk Region, Kazakhstan.

Salpingotus pallidus is in the subgenus Prosalpingotus. Two subspecies recognized.

Subspecies and Distribution.

S.p.pallidusVorontzov&Shenbrot,1984—CKazakhstan(NofAralSeaareainSEAktobe,WKaraganda,andKyzylordaregions).

S. p. sludskii Shenbrot & Mazin, 1989 — SE Kazakhstan (S of Lake Balkhash in N Almaty Region).

Descriptive notes. Head—body 53-61 mm, tail 96-113 mm, ear 8-10 mm, hindfoot 21-24 mm; weight 7-13 g. The Pallid Pygmy Jerboa is very small; secondary sexual dimorphism is expressed only in length of terminal tuft of tail, which is 2-5-3 times longer in males than females. Condylo-basal lengths of skulls are 16-3-18 mm, mastoid breadths are 14-9-16-8 mm, and maxillary tooth row lengths are 3-1-3-7 mm. Head and dorsum are yellow-gray, with scattered dark gray; sides and ventral pelage are pure white. Tail is fatty, with short black terminal tuft; fat deposits in tail are greatest in the anterior one-third and gradually become thinner toward tip. Hindfeet have three toes, covered below with brushes of white hairs; toes do not have conic calluses at their bases. Ears are short and tubiform. Auditory bullae are greatly inflated and strongly project from under braincase laterally and caudally. Mastoid cavity is large and completely subdivided into three sections by septum. In volume, mastoid cavity is about twice as large as tympanic cavity. Front surfaces of incisors are yellow. P! is present and slightly smaller in diameter than M”. Molars are low-crowned, with tuberculous surfaces; crown heights of unworn molars are c.75% of their lengths. Glans penis is small, thin, elongated, cone-shaped, and not subdivided into lobes, with surface covered by small single-vertex, backward-directed aciculae not differentiated in size. Os penis (baculum) is rudimentary and rachis-like; its length is about equal to one-tenth of length of glans penis. Chromosomal complement has 2n = 46 and FN probably 90.

Habitat. Flat or low hilly stabilized sands in desert zones, with grass ( Poaceae )sagebrush ( Artemisia , Asteraceae ) vegetation. In the Aral Sea region, dominant vegetation is A. arenaria and Agropyron sibiricum ( Poaceae ). In Lake Balkhash area, dominant vegetation is A. arenaria, Furotia ceratoides ( Amaranthaceae ), and Carex physodes ( Cyperaceae ).

Food and Feeding. Diets of Pallid Pygmy Jerboas contain seeds and insects; seeds are eaten more often in summer and insects more often in spring.

Breeding. Pregnant Pallid PygmyJerboas were recorded in May-July. Females produce one and, in some cases, two litters per year. Litters have 2-5 young.

Activity patterns. The Pallid Pygmy Jerboa is nocturnal. Activity starts just after sunset and was recorded only in the first one-half of night in early spring and all night in late spring and summer. Hibernation ends in the middle of April; dates when hibernation begins are not known.

Movements, Home range and Social organization. Home ranges of breeding female Pallid Pygmy Jerboas are c.0-6 ha. In captivity, social interactions are aggressive, with active fighting. Summer burrows of males have 2-3 entrances and one nest chamber at a depth of ¢.8 cm. Burrows of breeding females have up to four entrances, one nest chamber at depths of ¢.16 cm and 2-8 additional chambers.

Status and Conservation. Classified as Data Deficient on The IUCN Red List.

Bibliography. Shenbrot et al. (2008).

Figures

1. Five-toed Pygmy Jerboa (Cardiocranius paradoxus), 2. Kozlov’s Pygmy Jerboa (Salpingotus kozlovi), 3. Thick-tailed Pygmy Jerboa (Salpingotus crassicauda), 4. Heptner’s Pygmy Jerboa (Salpingotus heptnen), 5. Pallid Pygmy Jerboa (Salpingotus pallidus), 6. Thomas's Pygmy Jerboa (Salpingotus thomasi), 7. Balochistan Pygmy Jerboa (Salpingotus michaelis), 8. Long-eared Jerboa (Fuchoreutes naso), 9. Great Jerboa (Allactaga major), 10. Severtzov’s Jerboa (Allactaga severtzouvi), 11. Bobrinski’s Jerboa (Allactodipus bobrinsku), 12. Siberian Jerboa (Orientallactaga sibirica), 13. Gobi Jerboa (Orientallactaga bullata), 14. Balikun Jerboa (Orientallactaga balikunica)

Subspecies and Distribution. S.p.pallidusVorontzov&Shenbrot,1984—CKazakhstan(NofAralSeaareainSEAktobe,WKaraganda,andKyzylordaregions). S. p. sludskii Shenbrot & Mazin, 1989 — SE Kazakhstan (S of Lake Balkhash in N Almaty Region).