Diet composition of the scops owl (Otus scops) in central Romania

Abstract

Abstract Insect diversity correlates negatively with increasing management intensity of grasslands and with latitude. We supposed that similar patterns might be found in the diet spectra of insectivorous birds. The diet composition of the insectivorous scops owl was studied by analysing the prey remnants collected from 21 nests during 2008-2009 in an extensively cultivated rural area in the centre of the owl’s distribution range in Central Romania. Altogether 831 prey items belonging to 45 prey taxa were identified. Similarly to the other parts of the scops owl range, orthopterans were high dominant prey items (86.8%) - especially bush-crickets Tettigoniidae (78.6%). In food samles were found also beetles (Coleoptera, 5.7%) and rarely spiders Araneidea, moths Lepidoptera, mantids Mantodea, Hymenoptera and Neuroptera (<1 .5%). Vertebrates were rarely represented by rodents (2.5%) and passerines (1 .3%). The following diagnostic prey species were identified in 20 nests using the MDFM method: bush-crickets Tettigonia viridissima, Decticus verrucivorus, Metrioptera bicolor and other species of the family Tettigoniidae, the beetle Onthophagus spp., the cricket Gryllus campestris and other unidentified beetles Coleoptera g. sp. Furthermore, the scops owl’s diet in different parts of its range was compared. As expected, there were more Orthoptera and generally more prey taxa in food in the range centre than at its northern limit.