VARIABILITY OF THE TAWNY OWL (STRIX ALUCO) WINTER AND SPRING DIET IN A FOREST-STEPPE OAK FOREST

The results of analysis of 1284 tawny owl pellets (Strix aluco) collected in the territory of the National Park "Gomilshansky Lisy" (Kharkiv region, Ukraine) in 2002-2007 are given. These samplings reflect the bird's diet during late winter and early spring. Remains of 33 vertebrate species were identified in the owl pellets: 94.2% mammals, 3.8% birds, 0.1% amphibians, and 1.9% reptiles. Remains of bank vole (Clethrionomys glareolus) amounted to the largest share in pellets. Apart from this species, common shrew (Sorex araneus), yellow-necked mouse (Apodemus flavicollis), and striped field mouse (A. agrarius) became dominant species in different years. As the share of the bank vole in the tawny owl's diet decreased, species, the fluctuations in the number of which were not associated with those of the bank vole, predominated. In the winters with the low snow cover, forest mammal species prevailed in the tawny owl's diet; in the winters with the high snow cover, the share of prey species confined to forest edges and meadows increased.