This project investigates the effects of kinship on the behavior of wild chimpanzees (Pan troglodytes). Kinship plays an important role in determining how animals and humans behave. Evolutionary theory predicts that genetically related animals will develop close affiliative ties through the process of kin selection. Empirical observations are often consistent with this prediction. Despite the match between theory and observation, the explanatory power of kin selection continues to be debated. While some question whether the effects of kin selection have been overestimated, others continue to show how kinship can be used to explain the evolution of several aspects of animal social behavior. This research will provide behavioral observations of chimpanzees living in an unusually large community at Ngogo, Kibale National Park, Uganda. These observations will be combined with genealogical information derived from laboratory analyses of genetic markers from known individuals. Together, these data will be used to address five, unresolved questions regarding the impact of kinship on wild chimpanzee behavior and demography: (1) does kinship affect patterns of cooperation among male chimpanzees?, (2) do male and female chimpanzees associate non-randomly with their genetic relatives?, (3) do male chimpanzees share meat reciprocally with kin?, (4) are community males more closely related to each other than are females?, (5) do male chimpanzees use calls to recognize their genetic relatives? This project has broad theoretical, empirical, and practical significance. Theoretically, this research will contribute to the development of evolutionary models that are constructed to explain why animals behave in the way that they do. Empirically, this study will fill important gaps in our understanding of the behavior of our closest living relatives. Practically, research activities will help to safeguard one of the last vestiges of rainforest in East Africa; training and support of graduate students and Third World scientists will ensure that these conservation efforts are maintained in the future.