This project's goal is to experimentally study strict monogamy in a panarctic seagull, the black-legged kittiwake, in Alaska. It studies mate choice (which is crucial because no mixed strategy is used) in relation to indivdual quality, fitness and sexual conflict in strictly monogamous species. It is rooted in a detailed knowledge of the species’ biology and the merging of three teams (French, Austiran and Alaskan) with long-term experience researching kittiwakes. It uses the unique experimental Alaskan setting for wild populations.
Female choice of young sperm in a genetically monogamous bird: an experimental approach in kittiwakes When females copulate with multiple males the potential exists for female sperm choice. One mechanism of female sperm choice is post-copulatory sperm ejection. Females may increase the probability of being fertilized by preferred males by selectively retaining their sperm while ejecting the sperm of unfavored males. An alternative criterion to male quality for female sperm choice may be sperm age because old sperm degrade and can lead to zygote death or offspring inviability. Our team has recently found the first correlational support for the "young sperm" hypothesis: In monogamous kittiwakes females chose their mates’ sperm based on sperm age. Females mainly ejected sperm from seasonally early copulations and retained sperm from copulations performed soon before laying. The retention of old sperm was correlated with a 280% increase in hatching failure. We now propose to perform the first experimental test of the young sperm hypothesis in a wild species.