Doctoral Dissertation Improvement: Alternative Mating Strategies: 'Following' in Male Olive Baboons (Papio hamadryas anubis)

Behavioral ecologists have developed theory arguing that alternative mating strategies allow individuals to maximize reproductive success by varying the expression of traits in light of the individual's condition (e.g., body size or dominance status) or environmental circumstances. Little is known, however, about how individuals may pursue different strategies that depend upon varying conditions. The primary mating strategy of olive baboon (Papio hamadryas anubis) males is the well known sexual consortship. Such consortships are characterized by close spatial proximity, male defense of his access to the female, and relatively high rates of copulation between a male and estrous (fertile) female. What is less often appreciated about this view of the olive baboon mating system is that such consorting pairs are typically accompanied by a retinue of one to eight 'follower' males. These males maintain variable proximity to the consorting pair, interacting with both other 'followers' and the consorting pair.

The aim of this project is to examine the evolutionary significance of the 'following' strategy. The first objective is to determine the costs and benefits of alternative mating strategies for males. The second objective is to examine the impact of male condition on the expression of alternative mating strategies. The third objective is to determine if females influence these strategies. Behavioral data will be collected on two habituated groups of olive baboons in Laikipia District, Kenya for 18 months. Activity and social behavior will be recorded during ten minute focal samples of consorting pairs and any associated 'followers'. Synthesizing genetic paternity analysis with these behavioral data will examine the benefits of 'following'.

Currently, there is a gap in our understanding of alternative strategies: nonmammalian taxa are well studied and provide the foundation of relevant theory. There are, however, very few relevant detailed data from nonhuman primates which are of particular interest as this taxon exhibits relatively greater degrees of behavioral flexibility than the nonmammalian taxa. Therefore, the expression of alternative strategies in nonhuman primates provides an opportunity to incorporate more meaningfully behaviorally flexible taxa. In addition, alternative strategies are thought to be important throughout human evolution and help explain variation in mating behavior in contemporary human populations. Thus, there are compelling reasons to scrutinize further the nonhuman primates, in order to expand a currently limited base of animal models that facilitates understanding of the evolution of such strategies.