Female Competition And Dispersal Patterns In Chimpanzees

Anne Pusey is the James B. Duke Professor of Evolutionary Anthropology at Duke University.  She  is interested in understanding the evolution of sociality, social structure, and the patterns of competition, cooperation and social bonds in animal species, including humans. Most of Pusey’s work has focused on social mammals: lions and chimpanzees.  Current projects in her research group include studies of female social relationships and female settlement patterns, and the importance of alliances in males.

Abstract: Chimpanzees exhibit an unusual social organization in which groups of philopatric males jointly defend a large community range, while adult females are less social and spend most of their time in small, distinct but overlapping core areas within the community range. Long-term study of the Gombe chimpanzees reveals that females compete aggressively for access to space. Resident females aggressively resist the entry of immigrant females. Females are more aggressive to other females within than outside their core areas, and high-ranking females occupy higher quality, smaller, core areas, and maintain higher site fidelity than low-ranking females. Within-community infanticide of newborn infants by females has been observed several times over the course of the 52 year study and may be interpreted as an extreme manifestation of competition for space. At all chimpanzee study sites, the majority of females join new communities before breeding, probably to avoid inbreeding. At Gombe, a larger proportion have remained in their natal community than at other sites. Current research focuses on how levels of female competition and other factors influence the decision to disperse.