“Following,” an alternative mating strategy of male olive baboons (Papio hamadryas anubis)

Recent studies revealing the limitations of the Priority of Access model suggest the evolutionary significance of alternative mating strategies. The olive baboon’s (Papio hamadryas anubis) social system provide a valuable opportunity to examine a little studied alternative mating strategy- “following.” The most well known mating strategy of male baboons is individual aggressive competition for a consortship, a temporary relationship between a male and fertile female (Bercovitch 1995). What is less often appreciated about this phenomenon, however, is that the consorting pair is typically shadowed by a retinue of “followers” that maintain proximity to the consort pair for extended periods of time. Despite qualitative observations in several primate species, we know virtually nothing about the functional significance of this common male behavior, although it has been proposed as an alternative mating strategy. My dissertation addresses the following three questions regarding the factors influencing the expression of alternative male mating strategies: (1) what are the fitness costs and benefits of alternative mating strategies for males?; (2) how does male condition impact the expression of alternative mating strategies?; and (3) do intersexual interactions influence these strategies? I examined these questions using behavioral data and genetic data collected on olive baboons during a 19 month field study in Laikipia District, Kenya. My research indicates that following is an alternative mating strategy and can be directly linked to deviation from the Priority of Access Model, as observed through both behavior and infant paternity. Followers do not experience costs related to activity budget or feeding bout length, although they do face an increased risk of injury due to involvement in agonistic interactions with the consort male and spend less time interacting with other individuals. Following particularly provides lower ranking males with more opportunities to mate as theoretically predicted, although higher ranking males also use this strategy, depending on the distribution of reproductive opportunities. Female choice and male coercion also influence the expression of following, indicating the importance of intersexual interactions. My dissertation expands our understanding of alternative mating strategies by incorporating a little studied and behaviorally flexible taxon, and has implications for models of social evolution and our understanding of human evolution.Ph. D.Includes bibliographical referencesby Lisa Michelle Danis