Small mammals of the Pilica Forest based on the analysis of tawny owl Strix aluco pellets

Pilica Forest is a compact forest area in central Poland, cut by the Pilica river. Knowledge about the small mammals of this area was very limited. The aim of this study was to describe the theriofauna in this area, with a special focus on rare arboreal rodents from the Grilidae family. Between 2019 and 2021, we collected tawny owl pellets in two habitat types. The first habitat was Spała settlement, which is a human-modified landscape with built-up areas, a man-made pond and open areas such as meadows and farmland surrounded by forest. The second area where pellets were collected was located in the central part of the forest. A total of 770 mammal prey items were recorded. In the Grilidae family, only one individual of the hazel dormouse Muscardinus avellanarius was recorded. The pellets from the Spała area mostly contained the striped field mouse Apodemus agrarius and voles from the genus Microtus. In the pellets from the forest area typical forest dwelling species dominated: yellow-necked mouse Apodemus flavicollis and bank vole Myodes glareolus; both species accounted for more than 75% of the prey items. The number of mammal species identified was higher in the human-altered landscape than in the forest (18 and 11, respectively).