Difference in small mammal assemblages in the diet of the Common Barn-Owl Tyto alba between two landscapes

As an opportunistic predator, the Common Barn-owl (Tyto alba) proved to be an appropriate model organism to survey the composition of small mammal assemblages. This study analysed barn owls’ pellet samples from 14 localities containing 34 animal taxa and 4,088 prey items in two years (2015–2016). Two groups of samples (7–7 localities) were separated based on the dominance of semi-natural habitats and agricultural lands. Rarefaction analysis proved that the species richness and diversity of barn owls’ diet were significantly higher in semi-natural landscapes. The multiple regression analysis between PCA scores showed that in the agrarian landscape the abundance of generalist species was influenced by the proportion of forests, while the value of the trophic level index was determined by the size of arable fields. In the case of semi-natural landscapes, the abundance of the synantrop guild and generalist species, especially S. araneus and A. agrarius, was influenced by the proportion of urban areas, the number of habitats and the size of arable fields. The results of this study suggested that the small mammal consumption of the Common Barn-owl is significantly different in the two landscapes, which reflects the impact of habitat heterogeneity and agricultural activity on prey availability.