Marta Kociuba
Ornis Polonica 2012, 53: 283–292
https://doi.org/10.12657/ornis.2012.4.3
Abstract: The diet composition of the Ural Owl was studied in 2005–2007 at the Foothills of the Central Beskidy Mountains (the Carpathians, SE Poland). The analysed food samples (1039 prey items from pellets) were collected in nine locations (breeding territories) differing in the share of a forested area. The Ural Owl diet composition differed in relation to habitat type in the territory and forest rodent fluctuations. The Common Vole Microtus arvalis, Bank Vole Clethrionomys glareolus and Yellow-necked Mice Apodemus flavicollis were the main preys of the Ural Owl in a forest habitat in years with low number of forest rodents making up 28%, 21% and 11% of total prey biomass, respectively. In the year of rodent outbreak, biomass of forest rodents: the Bank Vole, Yellow-necked Mice and Field Vole Microtus agrestis constituted 36%, 33% and 10%, respectively. The Common Vole was hunted by the Ural Owl mainly in open habitats constituting ca 50% of total prey biomass. High contribution of the Bank Vole and Microtus Vole in the biomass resulted from similar crepuscular activity rhythm of these small mammals and the Ural Owl. Food niche breadth of the Ural Owl was lower in open habitat and forest habitat in the year of forest rodents outbreak compared to the forest habitat during the year of forest rodent crash. Presented results suggest that the Ural Owl is an opportunistic forager.
