Grey Hamster
Cricetulus migratorius (Pallas, 1773)
Order Rodentia
Family Cricetidae
Conservation status: in Bulgaria: Vulnerable VU [B1], BDA-II, III; International: IUCN (2004)-LR/nt.
General distribution. From Eastern and Southeastern Europe through Asia Minor, the Caucasus Mountains and Kazakhstan to Mongolia and part of China, in the south to Israel, Iraq, Iran and Pakistan.
Distribution and abundance in Bulgaria. Eastern Bulgaria, a rare species with low numbers. During the first catching of the species in Bulgaria, it was represented by 3, with respect to the total of 827 individuals of small mammals caught in Southeastern Bulgaria [1]. Its quantity in owl pellets [2, 3] is also extremely low. Judging from its finding in pellets from Southeastern Bulgaria in the recent years, it can be assumed that its population status is unchanged.
Habitats. The initial (natural) habitats are of a steppe and semi-steppe nature. In the northern part of its range it inhabits the lowlands but in the southern one it climbs high in the mountains. In Bulgaria it inhabits field margins and virgin lands overgrown with grass and low shrubs, amongst fields, the environs of low-stem deciduous forests, young orchards and vineyards [1, 4].
Biology. It digs out holes with a simple structure, often with two entrances and one chamber, at a depth of 20 cm to 1 m. It does not hibernate, although its activity decreases during the winter [5]. It is active during the night. It feeds on seeds of grasses, fruits [1, 4], rarely beetles and snails [6]. In the warm period of the year it yields up to three generations [7]. The number of the young in a litter are from 4 to 7. The young from the earlier generations start taking part in the breeding as early as the same season [8]. In many regions it has low numbers, especially in the northern and western parts of its range [9]. Considerable death-rate is caused by climatic factors: for example, cold winters with little snow, cold rains in the spring and autumn. Its major enemies are small rapacious mammals and nocturnal rapacious birds [2]. A probable competitor is the yellow-necked mouse, widely distributed in Bulgaria.
Similar species. None.
Negative factors. It is found in regions with a predominant traditional agriculture whose intensity in the recent years was low. Switching over to private agriculture and the fragmentation of the areas and their intensive processing associated with it, and the employment of considerable quantities of fertilizers and pesticides probably have a negative effect. The northwestern habitats are in the industrially degraded region of Stara Zagora – Radnevo – Maritsa Iztok. The enormous infrastructure facilities, the open mines, the dense road network, etc. have undoubtedly destroyed some of the habitats of the species.
Conservation measures taken. It is included in the Red Data Book of Bulgaria, 1985, in the category rare species, and in the Biological Diversity Act, Annexes 2 and 3.
Conservation measures needed. Estimate of the landscape structure in the regions where it has been found. Optimization of the agricultural use of lands.
References. 1. Peshev et al., 1960; 2. Simeonov, 1963; 3. Simeonov, 1964; 4. Markov, 1964; 5. Gromov et al., 1963; 6. Niethammer & Krapp, 1982; 7. Bashenina, 1951; 8. Vinogradov & Gromov, 1952; 9. Lozan, 1971.
Author: Vasil Popov
