This project will examine key factors that influence female competition and infant survival in wild sifaka lemurs in Beza Mahafaly Special Reserve, Madagascar. The unpredictable nature of resource availability in Madagascar renders sifaka a particularly appropriate species for examining female competition and the effects of aggression on reproductive success. Although aggression is one of the most commonly described sex differences, little is known about the costs and benefits of aggression for females. This study will investigate: 1) the effects of aggression and social status on access to resources; 2) the hormonal basis of aggression and competition; and 3) the effects of female aggression and social status on infant survival. Behavioral data and fecal samples will be collected on 16 adult females over five month field seasons from birth to weaning (July to December) in two successive years. The primary hormones of interest will be testosterone and cortisol, which are associated with aggression and stress, respectively. Hormonal analysis of fecal samples provides an integrated measure of hormonal activity without necessitating the capture and restraint of the animals. By focusing on both behavior and physiology, this research provides a unique opportunity to assess the effects of female aggression and competition on reproduction, which have been previously overlooked in studies of primates. Furthermore, this research will broaden our understanding of the evolution of female reproductive strategies across the primate order, and will shed light on the emergence of female competitive behavior within our own species. The broader impacts of this study include training of American and Malagasy students and furthering international collaboration. Students from the University of Antananarivo will have the opportunity to receive training in behavioral observations and fecal sample collection. In addition, the scope of this project requires recruiting field research assistants. Since many women are attracted to primatology, but not necessarily endocrinology, we will use this as an opportunity to encourage female students in the field of reproductive endocrinology. Thus, this research can provide training opportunities in laboratory as well as field methodologies. The data generated from this research will be entered into a database that will aid in accessibility for future research projects and collaborations. Finally, the practical application of this research is to better inform our understanding of sifaka behavior and reproduction, which is a necessary step in continuing conservation efforts for this highly endangered species. Beza Mahafaly Special Reserve is a protected area that is frequented by international tourists and contains an on-site museum. This provides a unique opportunity to educate the general public about lemur ecology and conservation.
