Diet comparison between two sympatric owls - Tyto alba and Asio otus - In the Negev Desert, Israel

We studied the diets of the barn owl Tyto alba and the long-eared owl Asio otus in an arid region in the northern and central Negev Desert, Israel. The diet of the two owl species consisted mainly of small mammals, but the long-eared owl consumed a significantly larger proportion of birds in all seasons than did the barn owl. Seasonal differences in the proportion of birds in the diet of the long-eared owl were mainly due to the consumption of migratory birds. Diet composition of each of the two species resembled more the diet of its conspecifics from other locations in that region and other seasons rather than that of the other species from the same location or season. This indicates that these two owl species do not consume prey in proportion to its availability, but prefer certain types of prey over others.