Forty years of dietary studies on barn owl ( Tyto alba ) reveal long term trends in diversity metrics of small mammal prey

摘要: The diet of predators is influenced by local conditions (e.g., characteristics habitat and microhabitat, seasonality, prey availability) therefore tends to change across time. In this paper, the composition barn owl ( Tyto alba ) in Italy was studied using a meta-analysis 47 articles (covering 212 independent sites, with multiple surveys for some thus giving total 290 datasets) between 1972 2012. General Linear Models were used assess effects year study site on four distinct diversity indices (species richness, dominance, Shannon-Weaver equitability). data collection factor all analyses. Year had greater effect than indices, but not significant evenness species richness. However, dietary dominance increased significantly over years, index decreased time, equitability also relative abundance various rodents did increase/decrease progressively although there inter-annual fluctuations. On other hand, insectivores tended decrease negative correlation frequency consumption Sorex spp. marginally Crocidura leucodon .