Nest site characteristics, patterns of nest reuse, and reproductive output in an Arctic-nesting raptor, the Rough-legged Hawk

Abstract

ABSTRACT Physical characteristics of nest sites are thought to influence their use by birds and the outcome of breeding attempts. The presence of preexisting nesting structures can also be an important factor influencing reuse patterns and reproductive success. We examined the relationships between nest-site physical characteristics, patterns of nest reuse, and reproductive output in Rough-legged Hawks (Buteo lagopus) breeding in the Canadian High Arctic. Because this species is a rodent specialist, we also examined the effect of variation in lemming density, their primary prey, on reproductive output. We monitored 109 nesting attempts over a 9 yr period and sampled physical characteristics of 87 known nesting sites in 53 territories on Bylot Island, Nunavut, Canada. The probability that a nest was used by a breeding pair increased with the distance to the nearest breeding conspecific, for nests sheltered by an overhang, and with lemming density. Hawk nests inaccessible to foxes and facing away from the n...