Nest site selection and predation driven despotic distribution of breeding long‐eared owls Asio otus

Abstract

Long‐eared owls Asio otus do not build their own nests. They occupy old corvid nests in either coniferous or deciduous trees. In my study area owls favoured coniferous over deciduous trees for nesting and occupied nest sites in that order. Comparing overall breeding output, I found no difference between the two kinds of nest sites, but among early nests there was a higher proportion of unsuccessful nests in deciduous trees. This difference was due to differences in predation rate, indicating that the owls' pattern of nest site occupation followed predictions from the ideal despotic distribution model. I also show that, due to a seasonal change in habitat quality, predator driven despotism, although present, can be well masked and hence difficult to detect.