8.

Gray Dwarf Hamster

Cricetulus migratorius

French: Hamster migrateur / German: Grauer Zwerghamster / Spanish: Hamster enano gris

Other common names: Armenian Hamster, Gray Hamster, Migratory Hamster

Taxonomy. Mus migratorius Pallas, 1773, Lower Ural River, W Kazakhstan.

Cricetulus migratorius is the only species in the migratorius group. In a genetic study by K. Neumann and colleagues in 2006, the genus Cricetulus was not monophyletic. Cricetulus migratorius was most related to Cricetus and Allocricetulus . They proposed placing C. migratorius in a new monotypic genus. Many subspecies have been described in the literature, but status of these subspecies is unclear. More comprehensive studies are needed. Following G. G. Musser and M. D. Carleton in 2005, no subspecies are considered here. Monotypic.

Distribution. NW Romania, Moldova, Ukraine, C & S European Russia, SE Bulgaria, E Greece, Turkey, Georgia, Armenia, Azerbaijan, Lebanon,Israel, E Syria, Jordan, N Iraq, Iran, Kazakhstan, SW Siberia (Omsk Region), Uzbekistan, Turkmenistan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, NW India (Jammu and Kashmir), N China (Xinjiang, Qinghai, Gansu, Inner Mongolia [= Nei Mongol], and Ningxia), and Mongolia.

Descriptive notes. Head-body 85-150 mm, tail 19-39 mm, ear 15-21 mm, hindfoot 14-18 mm; weight 20-58 g. Whiskers are up to 35 mm long. Gray Dwarf Hamsters from mountain habitats are bigger and darker than individuals from lowlands. Dorsal pelage is dark gray-brown to sandy brownish gray and clearly separated along sides from white or gray-white ventral pelage. Tail is short and white, mixed with some black hairs above. Cheek pouches extend to shoulders. Forefoot has five palmar tubercles, and hindfoot has six plantar tubercles. Skull is dorsally low and flat. Snoutis long and narrow. There is no supraorbital ridge. Incisive foramina is short and terminates before M'. Auditory bullae are very small and flat. Females have eight mammae. Karyotype is 2n = 22.

Habitat. Arid habitats such as dry grassland, steppe, desert, semi-desert, and alpine meadows at elevations up to 3600 m. In Mongolia, Gray Dwarf Hamsters occupy hills and mountains, oases, and valleys with shrubs and herbaceous plants in deserts and semi-deserts. In Turkey, habitats include fields and rocky slopes, with sparse grasses and shrubs. They also occur in agricultural land and gardens.

Food and Feeding. The Gray Dwarf Hamster eats roots, shoots, seeds, small fruits, green vegetation, snails, insects, and rarely small reptiles, amphibians, and other rodents. A study in Russia listed 37 different plant species in diets (most abundant Melilotus of Sficinalis, M. albus, and Medicago falcata, Fabaceae; Convolvulus arvensis, Convolvulaceae; Reseda lutea, Resedaceae; Agropyron repens and Bromus squarrosus, Poaceae; Atriplex patula, Amaranthaceae; Galium tricorne, Rubiaceae; Artemisia austriaca, Asteraceae; and Euphorbia gerardiana, Euphorbiaceae). The Gray Dwarf Hamster stores up to 400-500 g of food in storage chambers and gathers plants to store in “hay piles” for winter use.

Breeding. A female Gray Dwarf Hamster has up to three litters in a year. Litters have 1-13 young (usually 6-7); gestation lasts 16-21 days; and birth weights are 1-7-2-1 g. Adult coloris attained at 4-5 months old. Lifespan is up to two years.

Activity patterns. Gray Dwarf Hamsters are nocturnal and crepuscular and sometimes active during the day even when temperatures are low. They usually do not hibernate. In China, densities peak in June—October.

Movements, Home range and Social organization. The Gray Dwarf Hamster is solitary. It digs burrow systems with nesting chambers, food storage areas, and 2-5 entrances. Burrows can be 1-5 m deep and 2 m long. It also uses natural holes and fissures in soil. Important predators are owls, foxes, and jackals.

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

Bibliography. Aulagnier et al. (2009), Grimmberger et al. (2009), Krystufek & Vohralik (2009), Krystufek, Bukhnikashvili et al. (2016), Musser & Carleton (2005), Neumann et al. (2006), Roberts (1997), Smith & Hoffmann (2008), Yan Zhitang & Zhong Mingming (1984).