Tawny owls’ pellets were collected in north-eastern Poland at eight sites situated in forests or at forest edges and four sites in agricultural landscapes. In total, 2046 vertebrate prey items were found, including 1459 at the forest sites and 587 at the rural sites. The types of prey most commonly captured by forest owls were amphibians (25.7%) and Myodes glareolus (14.6%), while rural owls preferred amphibians (17.7%), birds (17.4%) and Mus musculus (16.2%). Comparisons of proportions of selected prey taken by tawny owls made between forest and rural habitats revealed that the capture frequencies of insectivores, M. musculus, Apodemus agrarius and birds are the best indicators of anthropogenic changes in tawny owls’ habitats.