Serial monogamy and sex ratio bias in Nazca boobies.

ABSTRACT: Biased operational sex ratios (OSRs) can drive sexual selection on members of the over-represented sex via competition for mates, causing higher variance and skew in reproductive success (RS) among them if an individual's quality is a persistent characteristic. Alternatively, costs of reproduction may degrade breeding performance, creating the opportunity for members of the limiting sex to switch mates adaptively, effectively homogenizing variance and skew in RS among the sex in excess. We tested these two contrasting models in a male-biased population of the Nazca booby (Sula granti) with demonstrated costs of reproduction with data on total RS over a 14-year period. Variances and skews in RS were similar, and males changed from breeder to non-breeder more frequently than females. Under t

SUBMITTER: Maness TJ 

PROVIDER: S-EPMC2275186 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature