Chimpanzees behave aggressively in a variety of contexts, but the underlying causes are often unclear. This project will be the first to study hormonal aspects of aggression and dominance in wild male chimpanzees. The study will collect and analyze hormonal data in order to investigate both the proximate and ultimate causes of chimpanzee aggression. In addition to chimpanzees, this study should provide a broader comparative framework for understanding human aggression, due to our own very close genetic affinity to chimpanzees. The research will be carried by examining testosterone levels, collected using a completely non-invasive method, in individual chimpanzees living in Kibale National Park, Uganda. Comparative data will be collected from a second community of chimpanzees living in Gombe National Park, Tanzania. Intersite differences in patterns of chimpanzee social behavior are not well understood, and this study is designed to help resolve these differences.
