European Hamster
Cricetus cricetus (Linnaeus, 1758)
Cricetus frumentarius Pall.: Kovachev, 1925: 30-31.
Order Rodentia
Family Cricetidae
Conservation status: in Bulgaria: Vulnerable VU [B1], BDA-II, III; International: IUCN [LR/lc], BeC-II, HD-IV.
General distribution. From Belgium through Central, Eastern and Southeastern Europe, Western Siberia and Northern Kazakhstan to the upper courses of the Yenisei and the Altai, part of China.
Distribution and abundance in Bulgaria. Northern Bulgaria. The country belongs to the regions where the species has a predomination of low numbers [1].
Habitats. A steppe species. In the European part of its range, it prefers agricultural areas in the lowlands and the valleys (at altitudes under 600 m) with a predominance of perennial herbaceous cultures on heavy soils with a considerable participation of a clay component with a total thickness of at least 1 m and a depth of underground waters under 1.2 m. Its abundance in cultivated areas is higher in comparison with the "wild" herbaceous habitats [2, 3].
Biology. It lives singularly in its own system of tunnels, with a depth of over 2 m [4]. It hibernates during winter but in warm weather awakens and goes onto the surface [2]. It feeds on green parts of plants, roots, seeds and fruits [2] and on invertebrates and small vertebrates [5]. It breeds during the warm period of the year. Pregnancy lasts for 17 days. One female yields 2 to 3 litters yearly, each with 2 - 10 (18) young ones. Sexual maturity is reached after the first wintering [1, 6, 7]. The duration of life does not exceed 4 years [6]. It falls prey to predatory mammals and rapacious birds [8, 9, 10]. It competes with the Romanian hamster.
Similar species. The Romanian hamster (Mesocricetus newtoni), but the European hamster is larger, the lower part of the body is entirely black.
Negative factors. Industrialization of agriculture, as a result of which the areas with perennial cultures decrease in number, the seeds are treated with pesticides, the fields are ploughed immediately after harvesting and are treated with rodenticides on a mass scale [11, 12, 13]. The switch-over to private agriculture and the fragmentation of the lands associated with it and their intensive processing, with the use of considerable quantities of fertilizers and pesticides.
Conservation measures taken. Included in the Red Data Book of Bulgaria, 1985, the Biological Diversity Act, Annexes 2 and 3 and the Berne Convention, Annex II.
Conservation measures needed. A programme for the assessment of the contemporary state of the species in Bulgaria must be developed and implemented. On that basis, a preservation plan must be worked out. Creation of "agrarian reserves": territories with an optimal structure for the arable lands in which agricultural practices harmful for the European hamster should not be employed. These measures should be stimulated by a system of compensations for farmers.
References. 1. Nechay et al., 1977; 2. Markov, 1960; 3. Grulich, 1978; 4. Grulich, 1975; 5. Gorecki & Grydielska, 1975; 6. Vohralik, 1974; 7. Grulich, 1986; 8. Simeonov, 1978, 9. Simeonov & Petrov, 1986; 10. Simeonov, 1966; 11. Stubbe et al., 1997; 12. Seluga, 1996; 13. Weidling, 1996.
Author: Vasil Popov
