Natal Philopatry and the Local Resource Competition Hypothesis: Data from the Common Goldeneye

Abstract

Sex-biased local resource competition (LRC) between parents and offspring has been suggested to exert selection pressure on progeny sex ratio variation in birds. In a recent article Weatherhead and Montgomerie (1995) questioned that the assumptions underlying the LRC hypothesis are applicable to birds. We here study the basic assumptions of the LRC hypothesis with data from the Common Goldeneye Bucephala clangula. First, we found strong female-biased natal philopatry, as expected in Anseriformes. Second, of all the females breeding in the study area, individuals born there comprised a major proportion each year. Third, we document a considerable overlap between home ranges of breeding mothers and daughters. Our results, combined with results from other Common Goldeneye populations and other Bucephala species, give strong support for the assumptions of the LRC hypothesis to be applicable to birds, at least to some species.