Prey specificity of the barn owl, Tyto alba, in the Great Fish River valley of the Eastern Cape Province

The responses of barn owls preying on a community of small mammals in the Great Fish River valley of the Eastern Cape have been determined by pellet analysis. The species composition of the prey was compared with the results of intensive trapping in adjacent habitat. Differences were apparent and their probable causes are discussed. The age-structure of several prey species found in the pellets was recorded following the establishment of relative age classes based on tooth wear, and interpreted in relation to the theory of prudent predation. There was no common pattern of age specific mortality. It was concluded that prudent and non-prudent behaviour may occur irregularly in space and time in these polyphagous barn owls, since the prey species varied in size and density, and were characterized by different reproductive strategies and survivorship patterns.