In many species, females mate with more than one male. This leads to sperm competition, where the sperm of several males compete to fertilize a female's eggs. All else equal, males that provide more sperm are expected to gain more fertilizations. However, the number of times a female mates and the extent to which she uses each male's sperm equally to fertilize her eggs also affect the number of fertilizations a given male is likely to achieve. Because sperm production entails a physiological cost, males are therefore expected to allocate different numbers of sperm to different females. In order to make predictions about these patterns in any species, investigators need information about how frequently females mate and how they use sperm. This research will provide that information for a species of Hawaiian cricket and will use it to predict patterns of male sperm allocation in this species. To determine female mating rate, individually marked females will be observed daily under semi-natural field conditions for ten weeks. To determine patterns of sperm use, the investigators will collect eggs daily and use genetic tools to identify the sires. These data will be corroborated in wild females by estimating, again using genetic tools, the number of mates and sires contributing to their sperm stores and offspring. This work will provide information on the sexual selection parameters operating in the field, crucial data that are rarely collected. The researchers will conduct outreach in Hawaii, in upstate New York by participating in a day of science education at a correctional facility for girls, and at Cornell by hiring an undergraduate research assistant from an underrepresented group.
