Taphonomic implications of roosting behavior and trophic habits in two species of African owl

As some of the most common predators of micromammals, owls are implicated in the formation of many fossil assemblages. Actualistic research on owl-accumulated assemblages has tended to focus on owls roosting in caves. Comparatively few data are available on the roosting behavior, and prey preference of owls in open habitats. This paper presents observations on the roosting and prey habits of two sympatric species of owl in the Serengeti region of northern Tanzania, the barn owl, Tyto alba affinis, and the spotted eagle owl, Bubo africanus. The barn owl and spotted eagle owl are found to segregate by roosting habit, with barn owls occupying cavity roosts and eagle owls appearing on the ground or in tree crowns. Previous studies comparing these two species suggested a close similarity in trophic habits. A comparison of large samples (MNI = 1012) at cavity and exposed roosts shows identical taxonomic representation, though differences are found in the relative abundance of some taxa and significant differences in prey body mass.