DISSERTATION RESEARCH: The role of reproductive age in the mating behaviors and preferences of female hamsters

Cornell University, Ithaca NY

Investigators

Abstract

What factors drive a female to choose a particular mate? This is an important question to scientists interested in animal behavior, sexual selection, and life history theory. Individual variation in female mate preferences and choice is common. However, our understanding of the mechanisms behind this phenomenon is still quite limited. There are a few proposed sources of individual variation in mate choice, and the purpose of this research is to investigate the role of reproductive age in female mate preference and choosiness. The research team will experimentally accelerate reproductive aging in young female hamsters to determine if reproductive age modulates mate choice behavior. This will be the first study to assess the effects of reproductive aging on behavior in mammals. The results of this project will lead to a better understanding of animal behavior, the factors that might affect individual differences in behavior, and animal reproduction. Reproductive quality declines with age in female mammals at a more rapid rate than other bodily systems. This rate varies among individuals, making it a potential source of variation in mate choice behavior. To decouple the effects of reproductive and chronological age on choosiness, young adult female Syrian hamsters will be treated with 4-vinylcyclohexene diepoxide (VCD), which specifically accelerates ovarian aging through oocyte depletion without compromising other physiological systems or life span. VCD-treated females will be given an opportunity to choose between a dominant and subordinate male hamster, and their preferences will be compared to vehicle-injected females. Young females typically choose the dominant male in this situation. If the preference for dominant male hamsters by young VCD-treated females is reduced relative to controls, then this result will emphasize the importance of reproductive quality, independent of chronological age, in explaining the individual variation in female mate choice. The products of this research will be widely disseminated and used for educational purposes. The project will also enhance scientific training of both graduate and undergraduate students in the fields of reproductive biology and animal behavior. Data generated by this project will include video recordings of female mate choice behavior and the tabulation of those data in Excel files. These data will be stored indefinitely in eCommons, a digital repository system at Cornell University. All eCommons content will be openly accessible worldwide.