EN
Beavers activity i.e. dam building, burrows and canals digging and foraging, radically changes the environment at both abiotic and biotic level. The consequences of beavers activity for other organisms are visible mainly through changes in their habitats. Such changes influence the number, species composition and species diversity of numerous flora and fauna species. One group of species that also may be influenced by beavers activity are small mammals (Rodentia and Soricimorpha). In Bieszczadzki and Magurski National Parks (southern Poland), small mammals community has not been studied at beaver sites yet. The aim of this study was to determine species composition, species diversity, and the relative abundance of small mammals at beaver sites, comparing to sections of the stream not inhabited by beavers (control sites). Small mammals were captured in three types of habitats – meadow, forest and riparian woodlots. Transects with live−traps were set there within beaver and control sites. Captures were conducted from one to three times annually, during 2−3 consecutive years. Total trapping effort amounted to 2540 trapdays. It was found that species composition, species diversity, and also the relative abundance of small mammals did not differ significantly between beaver and control sites. Only M. agrestis had significantly higher share in the community at the beaver sites. In mountain conditions, the presence of beaver sites probably does not affect the communities and abundance of small mammals significantly.