Seasonal variability in the diet of the long-eared owl Asio otus in a mosaic of field and forest habitats in central Poland

摘要

The diet composition of long-eared owls in central Poland was studied in the years 2004-2010 using standard procedures entailing the analysis of pellets. A total of 2111 prey items were identified in the material analysed, and voles {Microtus spp.) were found to dominate in both the summer (April-September) and winter (October-March) seasons. Nevertheless, the owls consumed voles and all rodents significantly more often in winter, while taking birds and insects significantly more often in spring andsummer. The food-niche breadth was thus greater in the summer period. Overall, the results confirm the dietary specialisation of long-eared owls toward predation on rodents of the genus Microtus.