No abstract

Following the expansion of agriculture in the Neolithic period, the common hamster has spread throughout Europe, and occurred abundantly until the recent past. However, in the last 45 years, populations declined markedly, partly attributable to urbanization and to major changes in agricultural practices. As a result, the species has been considered endangered at international levels as well as in most European countries. At the same time, the species has established populations in large Central and Eastern-European cities such as Vienna (Austria), Simferopol (Ukraine) and Nalchik (Russia), where it inhabits green spaces such as parks, gardens, embankments and buffer strips. In an attempt to reveal factors enabling hamsters to cope with urban environments, we reviewed historical data and habitat conditions of several urban hamster populations. We suggest that supplemental food resources and reduced predation pressure were the main factors promoting urban occurrence of common hamsters in the last 30 years. Its notable adaptability may be associated with higher stress resilience, ecological opportunism, polyphagy and higher fertility compared to species Unauthenticated Download Date | 5/13/18 9:19 AM 114 NATALIA -YU. relying on non-urban habitats. The phenomenon of synurbization implies coexistence of wildlife and our urban civilization, but at the same time conflicting interests in conservation and urban development. Thus, the common hamster might serve as a model species for efficient mitigation and compensation concepts in urbanism and spatial planning.

No abstract

Study of ecological adaptations, including torpor, related to survival through the adverse conditions of the autumn-winter season is important for both the estimation of the body reserves in mammals in general and the search for the ways to increase the cold stress resistance in humans. The changes in the body tempera ture during the period from October to May were studied in hamsters of six species under the natural photope riod and temperature conditions. Incidental winter torpor (a drastically decreased physiological activity) was detected in all species except Cricetulus griseus; in three of them, it had not been observed before. No specific combination of conditions causing torpor was identified. Apparently, it is determined by individual characteris tics of the animal. Torpors were the most frequent in January, at temperatures from -15 to -5°C; their depth was positively correlated with the ambient temperature. Since torpor is a rare event, it is assumed to be a stored resource of the body allowing animal to save energy and occurring only in extreme situations.

No abstract