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, Pa�istan 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 significantly 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 significant 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-significant differences in age and sex categories.