15.

Greater Long-tailed Hamster

Tscherskia triton

French: Hamster triton / German: Langschwanzhamster / Spanish: Hamster grande de cola larga

Taxonomy. Cricetulus (Cricetulus) triton de Winton, 1899, “N. Shantung, [China].”

In the past, 1. triton was placed in the genus Cricetulus, but analysis of mtDNA validated generic status of Tscherskia . Cansumys canus is considered as subspecies of 1. triton by some authors, but they are quite different morphologically and karyologically. Existing genetic evidence of conspecificity of Ischerskia triton and Cansumys canus may reflect misidentification of C. canus . Widely used subspecific names collinus and incanus have been changed for gender agreement. Some authors consider 13cherskia triton ningshaanensis named by S. Song in 1985 a subspecies of C. canus, but here is treated as a synonym of incana . Five subspecies recognized.

Subspecies and Distribution.

T:t.tritondeWinton,1899—EChina(CShaanxi,mostofShanxi,SHebei,Tianjin,Henan,Shandong,Anhui,Jiangsu,andNZhejiang).

T.t.colinaG.M.Allen,1925—CChina(NShaanxiandNWShanxi).

T:t.fuscipesG.M..Allen,1925—NEChina(InnerMongolia[=NeiMongol],NHebei,Beijing,Heilongjiang,Jilin,andLiaoning).

T. t. incana Thomas, 1908 — C China (Gansu, Ningxia, and S Shaanxi).

T. t. nestor Thomas, 1907 — Korea (including Cheju I) and Russian Far East (Primorsky Krai).

Descriptive notes. Head—body 142-220 mm, tail 65-106 mm, ear 17-25 mm, hindfoot 20-29 mm; weight 92-241 g. Male Greater Long-tailed Hamsters are slightly larger than females. Fur color of head and upperparts varies from pale brownish gray to dark grayish brown, gradually passing to ash-gray throat and underparts; some individuals have white spot on their chests. Legs are white. Tail is covered with short hairs, often white at distal ends. Condylobasal skull lengths are 35-6-46 mm, interorbital widths are 5-2—-6-1 mm, and molar tooth row lengths are 5-4-7 mm. Molars are low-crowned; upper molar rows diverge slightly in forward direction. Chromosomal complement has 2n = 28 (+0-2 supplementary B chromosomes) and FN = 34.

Habitat. Mainly farmlands but also meadows, shrublands, and abandoned fields and gardens, preferring upland parts of meso-relief and upper edges of ravines and penetrating into mixed broad-leaf forests in river valleys.

Food and Feeding. The Greater Long-tailed Hamster eats seeds, green plant parts, and insects; seeds dominate in diets in summer and autumn. It somtimes eats dead rodents. Seeds are stored in burrows; seed stores can be 10 kg.

Breeding. Breeding of the Greater Long-tailed Hamster occurs in April-October. Females can produce up to 3 litters/year. Litters have 2-24 young (usually 7-10). Females born in spring are reproductively mature at c.2 months old; those born afterJuly are mature after overwintering. Lifespan is c.1 year.

Activity patterns. Aboveground, Greater Long-tailed Hamsters are crepuscular and nocturnal. They do not hibernate, but in winter (November-March), individuals stay in burrows with entrances plugged by soil.

Movements, Home range and Social organization. Home ranges of Greater Longtailed Hamsters have one main living burrow and several shelter burrows. Main burrow has a complicated system of tunnels, one main vertical entrance, 2—4 exits plugged by soil, and nest chamber c.1-5 m deep. Shelter burrows are simple and consist of one vertical tunnel ending with small extension at depths of 35-60 cm. Greater Long-tailed Hamsters are solitary. They frequently scent-mark with flank glands. Contacts between individuals of the same sex are mainly aggressive. Male—female interactions are also mainly aggressive, and females permit males to mount only during estrus. Dispersal is significantly male-biased.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Giraudoux et al. (1998), Gromov & Erbajeva (1995), Kartavtseva & Alekseeva (1987), Kartavtseva et al. (1980), Koh Hung-Sun et al. (2013), Kostenko (1984), Liao Jicheng et al. (2007), Song Mingjing etal. (2005), Song Shiying (1985), Wang Jinxing et al. (1999), Zhang Jianxu et al. (1999), Zhang Jie (1987), Zhang Yongzu etal. (1997).