Climate predicts which sex acts as helpers among cooperatively breeding bird species.

ABSTRACT: Among avian cooperative breeders, help in raising offspring is usually provided by males or by both sexes. Sex bias in helping should evolve in response to sex-specific ecological constraints on independent reproduction, with mate shortage for males and breeding vacancy shortage for each sex. Given that male-biased adult sex ratios are prevalent among birds, we predict that male-only helping mainly occurs in temperate species where fast population turnovers deriving from low adult annual survival allow all adult females to hold breeding vacancies, whereas some males overflow as helpers, and both-sex helping in tropical species where saturated habitats prevent not only males, but also females from breeding themselves. As expected, we found that across species, adult survival increased towar

SUBMITTER: Zhang G 

PROVIDER: S-EPMC5310587 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature