The dataset contains information about the species and abundance of mammals, birds, and insects identified from pellets and bones found under Tawny owl (Strix aluco) roost sites in the Malé Karpaty mountains, Slovakia. Prey remains were collected under trees and cliffs with shelters, most of which were used as roost sites. Material was sampled from 2014 onwards, with some sites being repeatedly sampled. The file includes information regarding the sample type: preserved pellets or bones. Bones were found within the 2 cm surface layer. New sites are added annually. The bones and animal remains are stored in the author's private collection.