Orientallactaga balikunica, Hsia Wupinq & Fang Xiyeh, 1964

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 : 88

14.

Balikun Jerboa

Orientallactaga balikunica

French: Gerboise de Barkol / German: Balikun-Pferdespringer / Spanish: Jerbo de Balikun

Taxonomy. Allactaga bullata balikunica Hsia Wupinq & Fang Xiyeh, 1964 ,

Balikun (= Barkol), Xinjiang, China.

In the past, O. balikunica was considered as subspecies of O. bullata . Phylogenetically, it is the sister species of the O. sibirica + O. bullata clade. Monotypic.

Distribution. N China (NE Xinjiang, NW Gansu, and NW Inner Mongolia [= Nei Mongol]) and S Mongolia.

Descriptive notes. Head-body 120-135 mm, tail 170-195 mm, ear 34-39 mm, hindfoot 58-65 mm; weight 63-88 g. There is no significant secondary sexual dimorphism. Condylo-basal lengths of skulls are 29-4-31-4 mm, zygomatic breadths are 20-8-23-1 mm, and maxillary tooth row lengths are 5-4-6-5 mm. Head and dorsum are grayish brown; sides and ventral pelage are pure white; tail banner is wide and well flattened, bi-colored, with long black subterminalfield and short white terminal tuft; and ventral side of black subterminalfield is solid and not dissected along tail rod by wide white stripe. Toes of hindfeet are covered from below with brushes of long soft hairs, black inside and whitish outside; conic calluses at bases of toes are large but relatively low, with wide bases. Auditory bullae are significantly inflated. Mastoid cavity is extremely small and not subdivided into sections; tympanic cavity is large. Front surfaces of incisors are white; incisors are weakly deflected forward. P' is relatively large but slightly smaller than M?. Molars are medium-crowned, with terraced masticatory surfaces; crown heights of unworn molars are 100-130% of their lengths. Glans penis is egg-shaped, slightly compressed in dorso-ventral direction, subdivided by deep longitudinal dorsal fold into two lateral lobes; surfaces of lobes are covered by single-vertex, backward-directed aciculae slightly increasing in size in backward direction. Os penis (baculum) is absent. Chromosomal complement has 2n = 48 and FN = 96.

Habitat. Extra-arid desert on rock-gravel hill slopes, with sparse shrub vegetation.

Food and Feeding. The Balikun Jerboa is omnivorous. Seeds comprise 19-34% of the diet, insects 17-23%, green plant parts 28-57%, and roots and bulbs 4-21%.

Breeding. Breeding of the Balikun Jerboa occurs in June-August. Litters have 1-5 young (average range 1-5-2-5).

Activity patterns. The Balikun Jerboa is nocturnal. Aboveground activity usually starts immediately after sunset in June and 30-60 minutes after sunset in July-August.

Movements, Home range and Social organization. Maximum running speed of the Balikun Jerboa is 8-7 m/s. Home range averages 4-3 ha for males and 3-2 ha for females. Home ranges of females are isolated; home ranges of males widely overlap those offemales and other males. Summer burrows usually consist of main tunnel, starting from main entrance at the ground’s surface and sloping down with 1-2 right-angled turns to the nest chamber. One additional tunnelstarts from middle of main tunnel and leads to emergency exit near ground’s surface. Entrance is usually closed with soil plug. Total length of tunnels is ¢.2:5 m; nest chambers are 12-15 cm in diameter and ¢.60 cm deep. Night shelter burrows are absent. In the wild, Balikun Jerboas are solitary. Captive pairs are usually agonistic atfirst, followed by one individual attempting to escape.

Status and Conservation. Classified as Least Concern on The [UCN Red List (as Allactaga balikunica ).

Bibliography. Pisano et al. (2015), Sokolov, Lobachev & Orlov (1998), Wang Sibo & Sun Yuzhen (1997).

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)

Distribution. N China (NE Xinjiang, NW Gansu, and NW Inner Mongolia [= Nei Mongol]) and S Mongolia.