A comparative laboratory study of the preservation of different rodent bones in pellets of Strigiformes

Abstract

Studies of variation in preservation of different skeletal elements in the pellets of birds of prey helps us understand which bones should be used for effective and reliable diet analyses. The preservation of cranial and postcranial elements of skeletons of laboratory mice was studied in owl pellets. The research was conducted with three male individuals of three species: Long-eared Owl, Tawny Owl and Pygmy Owl. The owls were fed with adult and immature mice in laboratory conditions. The preservation of bones was defined as the ratio of the number of whole specimens of a certain bone to the total number of bones which were contained in the body of one mouse. The largest and the most massive bones had a high preservation. The upper part of cranium and the large bones of limb girdles had the highest preservation in the owl pellets. The bones of immature mice had higher preservation in the pellets of Pygmy Owl compared to Long-eared and Tawny Owl. Age differences in bone size and thickness were explained the variation in preservation of immature and adult mouse bones.