Which Bat Species are Captured by the Long-eared Owl Asio otus (Linnaeus, 1758) (Aves: Strigiformes) in Poland?

Twenty-two bat individuals were identified to the species level in published and unpublished data based on diet samples of Asio otus from Poland collected between 1989 and 2022. Of the seven species that made up the owl prey, Myotis nattereri (9 cases) and Plecotus auritus (6 cases) were by far the most numerous. The proportion of bats in the vertebrate prey was very low. In the central and north-eastern parts of the country, it was 0.05% between 1980 and 2002 and 0.04% between 2010 and 2024, although the differences were not statistically significant. The hypothesis that bat species associated with foraging in open areas are more abundant in the diet of this owl species, which hunts mainly in agricultural landscapes, could not be confirmed. The vast majority of prey were species that hunt near trees, in forests or over bodies of water. This indicates that the bats are mostly caught in situations other than typical foraging, e.g. near their roosts or resting places of owls. The fact that typical forest bats (Myotis bechsteinii, Barbastella barbastellus) were found in the winter diet of A. otus suggests that they were caught near underground hibernacula, which may be located in open areas away from forests.