Sex and age classes of prey items (rats/mice) in the diet of the Barn Owl (Tyto alba) in Sindh, Pakistan

Abstract

Barn Owl (Tyto alba) pellets were collected from nine locations and two districts of Sindh, Pakistan and 937 prey items were recovered from 619 pellets. Rats/mice (59.6%) were the most dominant food items consumed by the Barn Owl. Shrews (22.3%), bats (1.3%), birds (12.0%), insects (1.3%), frogs (2.2%) and plant materials (1.3%) were found in their diet as well. Study of the pelvic girdle bones of rats/ mice, used only for sexing, proved to be a useful device in population dynamics. In the pelvic bone, pelvic symphysis is found only in female rats/mice developed as a result of sex hormones that occur during gestation. Among the diet of rats/mice, males were found to be signiicantly dominant. Tooth wear patterns on the occlusal surfaces of molariform teeth of the rats/mice were found to provide an effective criterion for establishing age classes of rats/mice. In the present study, adult rats/mice were found to be dominant over sub-adults and old adults. ANOVA showed signiicant differences in the number of rats/mice and shrews (prey items) and the other prey items / plant materials in the diet of Barn Owls in the district Thatta and district Karachi. Chi-square test disclosed non-signiicant differences in age and sex categories.