Effects of a forest landscape on the prey composition of the Common Barn-owl Tyto alba in southern Bulgaria

Abstract

The diet of the Common Barn-owl in a forest- and shrub-dominated hunting area in the Strandzha Mountains, southern Bulgaria, was identified from 516 prey specimens. Shrews (52.9% by number, 26.7% by biomass) and rodents (42.1% N, 71.5% B) were prevalent. Among them, White-toothed shrews, Criocidura sp., (45.3% N, 21.4% B) was the most numerous prey genus. Mice, Apodemus sp., (15.7% N, 29% B) contributed with the largest share to the food biomass due to high predation of Striped field mice, A. agrarius, (12.2% B). The proportions of forest species in diet (Apodemus sp, Sorex sp., and dormice Gliridae) increased with the higher proportion of forest habitats (forests and shrublands cover more than 25% of the area) in most Barn Owl hunting territories in southern Bulgaria.