Doctoral Dissertation Research: Great Ape Adolescent Social Behavior

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The selection of mates and subsequent production of offspring are key components of the evolutionary process, but what behaviors do animals employ to access mates? In this dissertation project, the co-PI will investigate the aggressive and affiliative strategies that young male chimpanzees use to mate with females and how these strategies change during development. Results of this research will clarify our understanding of the development of coercive behaviors in male chimpanzees and may provide a perspective on the evolutionary context of this behavior. In addition, this research will contribute to the conservation of endangered chimpanzees and other wildlife through educational outreach efforts at the research site. Male animals frequently compete for mates. As they do so, relatively large, strong, experienced, and old males are typically favored in competition and consequently sire offspring. Prior research conducted at Ngogo in the Kibale National Park, Uganda, however, indicates that young adult and adolescent male chimpanzees, who are socially and physically immature, father many offspring. Adolescent males father infants born to adolescent females, while young adult males sire the infants of adult females. In this project, the co-PI will collect behavioral and morphological data on an large cohort of adolescent and young adult male chimpanzees at Ngogo, to investigate the strategies young male chimpanzees employ to mate with females and how these strategies change during development. Specifically, she will examine whether young male chimpanzees use aggression to coerce females to mate with them and whether sex differences in body size affect their ability to do so. In addition, she will determine whether young males improve their evolutionary fitness by affiliating with adult females during infancy and juvenility when males are still dependent on their mothers or later during adolescence by forging strong social bonds with adolescent female peers.