The proposed project will analyze original data systematically collected between 1975 and 1989 on free-ranging chimpanzees in the Gombe National Park, Tanzania. The data records are housed in Dar es Salaam and must be reviewed there. The purpose is to test the hypothesis, generated in studies of captive animals, that there is a correlation between the degree of social contact and the pattern of genital swelling in wild female chimpanzees. It is well known that human females who live together tend to synchronize their menstrual cycles (the dormitory effect), suggesting that social contact is the significant factor regulating synchrony. Laboratory experiments have indicated that synchronous onset of estrous swelling in chimpanzees is also mediated by social contact. This project will determine whether similar synchrony can be demonstrated under natural conditions, thus adding to our knowledge of the mechanisms involved in the reproductive life cycles of chimpanzees.
