Fledging dates of NuthatchesSitta europaeain relation to age, territory and individual variation

Publisher Website
Google Scholar
Abstract
The timing of fledging in a population of nuthatches, breeding mainly in natural holes, was studied in 5 successive breeding seasons, with a total of 70 successful broods. Fledging date varied significantly among years, and was correlated with female age and body size, but not male age or body size. Fledging dates varied significantly among territories, but the responsible factors are not clear and may not be related to other aspects of territory quality. First-year females immigrating in winter or spring bred later than residents, which may be due to an indirect effect of territory quality. There is no evidence for an effect of duration of the pair-bond nor of changes in nest site between years. An important advantage of breeding early in nuthatches is that juvenile birds start to establish territories within weeks of fledging, and early young have a better chance of obtaining a high quality territory.