| Abstract: | Capsules Sites are selected as part of an antipredator strategy. Aims To assess if site choice depends on habitat variables at nest sites and if habitat quality influences reproduction. Methods Breeding density was explored in northwestern Switzerland from 1992 to 1996. Habitat variables were examined at 38 breeding sites and were compared with data collected from random sites. Habitat quality was estimated using the discriminant function scores of the nesting sites. Results Breeding density was found to vary between years; more pairs bred and raised more young in 1993, a year of high vole abundance. Long-eared Owls tended to avoid the vicinity of buildings; they occupied sites with denser forest edges, greater canopy cover, and with more conifers than random sites. I found no statistical evidence that they used less optimal sites when the population was high. The number of fledglings increased with habitat quality, but did not vary with any of the habitat variables taken separately. Conclusion Long-eared Owl selects nesting habitat as part of an anti-predator strategy, but the measures of territory quality did not seem to be a limiting factor for the population. |
