Maternal condition and previous reproduction interact to affect offspring sex in a wild mammal.

ABSTRACT: Trivers and Willard proposed that offspring sex ratio should vary with maternal condition when condition, meant as maternal capacity to care, has different fitness consequences for sons and daughters. In polygynous and dimorphic species, mothers in good condition should preferentially produce sons, whereas mothers in poor condition should produce more daughters. Despite its logical appeal, support for this hypothesis has been inconsistent. Sex-ratio variation may be influenced by additional factors, such as environmental conditions and previous reproduction, which are often ignored in empirical studies. We analysed 39 years of data on bighorn sheep (Ovis canadensis) that fit all the assumptions of the Trivers-Willard hypothesis. Production of sons increased with maternal condition only for

SUBMITTER: Douhard M 

PROVIDER: S-EPMC5014044 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature