13.

Tibetan Dwarf Hamster

Cricetulus kamensis

French: Hamster du Tibet / German: Tibet-Zwerghamster / Spanish: Hamster enano de Tibet

Other common names: Kam Dwarf Hamster, Kam Rat-like Hamster, Tibetan Hamster

Taxonomy. Urocricetus kamensis Satunin, 1903, Moktschjun River, Mekong District, NE Tibet, China.

Cricetulus kamensis is in the kamensis species group. There has been much debate about taxonomy of kamensis, lama, tibetanus, and kozlovi. A. T. Smith and R. S. Hoffmann in 2008 and The IUCN Red List recognized lama and tibetanus as separate species. The taxa kozlovi was listed as subspecies of kamensis . Here, G. G. Musser and M. D. Carleton in 2005 and Wang Sung and Cheng Changlin in 1973 are followed, including lama, kozlovi, and tibetanus as synonyms. Further studies are needed to clarify this taxonomy. Monotypic.

Distribution. China (Qinghai, Tibet [= Xizang], and NW Sichuan).

Descriptive notes. Head-body 88-112 mm, tail 30-64 mm, ear 14-18 mm, hindfoot 15-18 mm; weight 20-40 g. Measurements are united between three forms. Dorsal pelage of morphotype kamensis is dark grayish brown and might have black spots or streaks. Upper parts of hindlegs are black. Ventral pelage is grayish white, and sides mostly have wavy border between dorsal and ventral colors. Tail is whitish with narrow dark gray-brown stripe above. In morphotype lama, pelage is lighter, similar to kamensus but without any dark dorsal fur. Upper thigh is not black as on kamensis . Underside is grayer than on kamensis, and there is no wavy line on sides. Tail is shorter than kamensis, dark on top and white below. In morphotype tibetanus, dorsal pelage is nearly ocherous,fading to lighter sandy toward forehead, cheeks, and neck. Ears are dusky brown, with narrow edges of white on tips and small tufts of white at bases. Tail is bicolored, dusky above and pure white below. Ventral side and back of feet are white. Skull is slightly convex, and dorsal side is arched. Incisive foramina is short, not reaching anterior edge of first upper molar. Auditory bullae are small.

Habitat. Shrubby marshes, open steppe, and high mountain grasslands at elevtaions of 3300-4100 m. Habitat of lama and tibetanus is presumed to be similar to that of kamensis .

Food and Feeding. The Tibetan Dwarf Hamster eats grass seeds, grains, and insects and stores food for winter.

Breeding. Reproduction occurs in May-August and peaks in June-July. Litters have 5-10 young (usually 7-8).

Activity patterns. Tibetan Dwarf Hamsters are active during the day and night.

Movements, Home range and Social organization. The Tibetan Dwarf Hamster digs simple dens to depths of ¢.50 cm.

Status and Conservation. Classified as Least Concern on The IUCN Red List (under C. kamensis, C. lama, and C. tibetanus, all classified separately as Least Concern and considered morphotypes here).

Bibliography. Jiang Zhigang, Ma Yong, Wu Yi, Wang Yingxiang, Zhou Laiya et al. (2015), Musser & Carleton (2005), Smith (2016a), Smith & Hoffmann (2008), Smith & Johnston (2008d, 2008e), Wang Sung & Cheng Changlin (1973).