Comparison of Winter Diet of Long-eared Owls Asio otus (L., 1758) and Short-eared Owls Asio flammeus (Pontoppidan, 1763) (Ayes: Strigidae) in Northern Turkey

This study compares the winter diet of short-eared owls (Asio flammeus) and long-eared owls (Asio otus) around the Yedikir Dam (Amasya, Northern Turkey). A total of 309 pellets containing remains of 557 individual prey items were found. The diet composition of both owls consisted of only six small mammals dominated by the east European voles (Microtus levis) in similar proportions (58.9% by number, 51.0% by biomass in A. fiammeus and 55.9% by number, 63.3% by biomass in A. otus). Mus macedonicus was another important prey in the diet of short-eared and long-eared owls (F = 10.0% and F = 18.8%, respectively). Slightly preferred prey were the yellow necked mouse (Apodemus flavicollis), Turkish hamster (Mesocricetus brandti) and the grey dwarf hamster (Cricetulus migratorius). A. flammeus and A. otus had very similar diets in Northern Turkey. The food-niche breath (FNB) was low in the owl species. The studied owl species showed high level of niche overlap (R-o= 0.886).