Diet composition and prey diversity of Tengmalm’s owl Aegolius funereus (Linnaeus, 1758; Aves: Strigidae) in central Serbia during breeding

Abstract

Annual variation in the diet, composition, and prey diversity of Tengmalm’s owl Aegolius funereus (Linnaeus, 1758) wasinvestigated in high-mountain coniferous forests of Mt. Kopaonik (central Serbia) during 3 consecutive years. Prey remains anddecomposed pellets (detritus) were collected at the bottom of nest-boxes during 2 separate periods: during mating and after nesting.Prey remains such as maxillae, mandibles, beaks, or feathers were used for prey identification. In total, 438 prey items were separatedand identified. Small mammals represented the most numerous class of prey (87.23%). The most frequent prey item was bank voleMyodes glareolus (23.29%). During the nesting season the proportion of voles eaten was significantly higher in comparison with themating period. The mean prey weight was 20.74 g. In the study area, according to diversity index calculations, prey diversity was highand it seems that the number of breeding attempts by Tengmalm’s owl showed dependence on the annual abundance of small rodents,but further research is needed to confirm this assertion.