The Winter Foods of Some Indiana Owls

Abstract

Some winter foods for 4 spp. of owls (Tyto alba pratincola, Asio wilsonianus, A. f. flammeus, and Bubo v. virginianus) are reported for Tippecanoe Co., Ind. A total of 430 complete pellets were examined plus 139 whole or part pellets of the long-eared owl. In the aggregate remains of 1098 prey items were noted of which 1046 or 95.2% of the total were mammals. Of these there was a marked preponderance of Microtus o. ochrogaster comprising 557 individuals or 50.7% of all the items. This sp. was locally very abundant at the time when most of the owl pellets were being produced. Including an improbable maximum of 43 cottontails, remains of only 45 game spp. were found which were 4.1% of all the prey. Although the pellets were collected from localities which supported altogether 23 owls of 4 spp., the great horned owls accounted for 42 of the game spp. Therefore, it was concluded that for the period and place which this study embraces, general owl predation upon game was negligible. The great horned owl preyed to some extent upon field-living Norway rats and this was noted as beneficial to human interests.