17.

Eversmann’s Hamster

Allocricetulus eversmanni

French: Hamster d’'Eversmann / German: Eversmann-Zwerghamster / Spanish: Hamster de Eversmann

Taxonomy. Cricetulus eversmanni Brandt, 1859, near Orenburg, Orenburg Oblast, Russia. Two subspecies are recognized.

Subspecies and Distribution.

A.e.eversmanniBrandt,1859—fromSEEuropeanRussia(EofVolgaRiver)EtoSWSiberia(OmskRegions)andNW&NKazakhstan(WestKazakhstanandWAtyrauEtoPavlodar).

A. e. beljaevi Argyropulo, 1932 — W, C & E Kazakhstan (from E Atyrau E to East Kazakhstan Regions) and NW China (N Xinjiang).

Descriptive notes. Head-body 103-136 mm, tail 20-31 mm, ear 13-25 mm, hindfoot 16-20 mm; weight 32-68 g. Head and upperparts vary from grayish brown to sandy ocher; underparts are white, with dark spot of variable size on breast between forelimbs. Chromosomal complement has 2n = 26 and FN = 38-40.

Habitat. Steppe and semi-deserts but also forest steppe. Eversmann’s Hamster prefers patches with grass and sagebrush ( Artemisia, Asteraceae), salt depressions, sands, abandoned fields, edges of crop fields, and sometimes buildings in human settlements.

Food and Feeding. Eversmann’s Hamster mainly eats seeds, insects, and mollusks; it sometimes eats lizards, small mammals, and birds. Food is cached in separate storage burrows.

Breeding. Main breeding season of Eversmann’s Hamster occurs in April-October, although some females reproduce in winter. During the breeding season, old overwintering females can produce 2-3 litters in northern parts of distribution and 3-4 litters in southern parts. Some yearling females have 1-2 litters in northern parts and 2-3 litters in southern parts. Litters have 3-14 young; mean litter sizes are 6-2-8-9 young depending on geographic regions.

Activity patterns. Eversmann’s Hamster is mainly nocturnal. Summer activity starts at 19:00-22:00 h and ends at 04:00-06:00 h. Aboveground activity lasts 3-5 hours. Most, but not all, individuals hibernate from December to February-March. Hibernation is characterized by alterating periods of deep sleep lasting 10-50 hours when body temperature drops to 5°C and emergence when body temperatures increase to 36-37°C.

Movements, Home range and Social organization. Home-range sizes of Eversmann’s Hamster are 0-1-3 ha; males have larger home ranges than females. Home ranges of males widely overlap with those of females and other males, but home ranges of females are exclusive and do not overlap. Burrows are simple and have a tunnel that starts vertically from the entrance and then slopes down to the nest chamber, 20 cm in diameter and c.40 cm deep. Under laboratory conditions, behavioral interactions are extremely aggressive, except male-female interactions during courtship and mating. Under natural conditions, individuals usually avoid direct contact.

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

Bibliography. Gromov & Erbajeva (1995), Korol'kov & Krivosheev (2008), Malikova et al. (2005), Okulova et al. (2014), Polyakov et al. (2012), Popov (1960), Romanenko et al. (2013), Ryurikov et al. (2003), Shchepotyev (1970), Shlyakhtin et al. (2009), Sludskiy et al. (1977), Ushakova et al. (2012), Vekhnik et al. (2009), Zakharov & Korytin (2005), Zhang Yongzu et al. (1997).