OWL PELLETS AS A SOURCE OF DNA FOR GENETIC-STUDIES OF SMALL MAMMALS

Owl pellets contain a good skeletal record of the small mammals consum ed, and correspond to the undigested portions of prey which are regurg itated. These pellets are easy to find at the roosting site of owls. A s it has been demonstrated that amplifiable DNA can be isolated from a ncient bone remains, the possibility of using owl pellets as a source of DNA for small mammal genetics studies via the polymerase chain reac tion has been investigated. The main uncertainties when isolating DNA from such a material are firstly the possibility that the extracted DN A would be too degraded during the digestion in the stomach of the owl , and secondly that extensive cross-contaminations could occur among t he different prey consumed. The results obtained clearly demonstrate t hat cross-contamination does not occur, and that mitochondrial and nuc lear DNA can be amplified using skulls of small mammals found in owl p ellets as a source of DNA. The relative efficiency of two methods of D NA extraction is estimated and discussed. Thus, owl pellets represent a non-invasive sampling technique which provides a valuable source of DNA for studying population genetics of small mammals.