Social Influences on Reproductive Decisions- revised

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

The social environment can influence the individual in many different ways. Social factors can affect learning, development and even health. The focus of this proposal is to examine how different types of social environments can impact the health of parents and offspring. The model system under study is the brown-headed cowbird. Cowbirds are an excellent model for investigating the influence of social environments on health because, being obligate brood parasites, they engage in no parental care, thus the viability of their young is not confounded by parental abilities. This project is designed to take an integrative approach in examining the function and cause of social influences on mating, reproductive success, and health of parents and offspring. It combines observational studies of large groups of birds with proximate measures of circulating hormone actions. Captive flocks of cowbirds will be observed and experimentally manipulated (by changing the social composition of the flocks, and with hormone implants). This procedure provides (1) control over the social experiences the birds gain, (2) measures of reproductive success, and (3), measures of the growth and vigor of the young. This work has the promise to advance knowledge on where and when selection may act on flexible behavior patterns in social organisms and to reveal the strength of cultural processes influencing health and viability. In addition, the lab has a strong educational mission; it is attractive to broad range of students including underrepresented groups. Finally, cowbirds are a species of concern due to their ability to reproduce at high rates. This work has the potential to provide new knowledge about the factors that stimulate female reproduction that could be used for management and conservation programs.