Feeding specialization of urban Long-eared Owls, Asio otus (Linnaeus, 1758), in Jerusalem, Israel

The diet of Long-eared Owls (Asio otus) that breed and hunt within the grounds of a bird-ringing station located in a large city park in Jerusalem, Israel, was investigated. 13 species of bird were the most common prey group (91% by number) with a frequency of occurrence of 99% in pellets, with House Sparrows, Passer domesticus, and Blackcaps, Sylvia atricapilla, as the most frequent prey species (22% and 17% by number). 29% of the bird specimens found in pellets had been ringed at the ringing station. The frequency of residential and migratory passerines caught by Long-eared Owls and ringed at the ringing station was similar, whereas more migrants were captured and ringed during the spring than summer. A comparison of bird species that were hunted relative to their frequency in the habitat revealed that the owls caught more Sylvia warblers than expected. Long-eared Owls in this study most probably specialised on birds because of the abundance of passerines and the lack of small mammals.