Birds as prey of owls: an intra- and interspecific comparison

A review on birds as prey of owls is presented based on 3639 prey lists from literature. The percentage of birds varied strongly between prey lists. Differences between owl species were moderate, only Eurasian Pygmy-owl (Glaucidium passerinum) and Eurasian Eagle-owl (Bubo bubo) showed over all higher percentages of birds in their prey. Differences between seasons were small. The variation within the same owl species (intraspecific variation) across the study regions was larger. In several cases, the percentage of birds as prey tends to have declined over the last decades. Although owls generally prey on mammals, birds are an important alternative prey.
Keywords: Food composition, birds as prey, Strigiformes