Variability in reproductive success viewed from a life-history perspective in baboons.

Nonhuman primates, like humans, mature slowly and have low fertility during a relatively long life. As data have accumulated on life-history patterns of nonhuman primates, comparative studies have yielded important insights into the evolution of this slow life-history style of primates. However, in order to understand selection pressures and evolutionary potential within species, it is important to complement comparative studies with detailed studies of life-history variability within species and to identify sources of this variability. Here we present a summary of how foraging environment, social status, and group size (a measure of population density) contribute to within-population variance in reproductive success for savannah baboons. We also discuss the extent to which savannah baboons, with their highly flexible and adaptable behavior, change their foraging environments by shifting home ranges and seeking rich food sources and how low-ranking females, which disproportionately bear the costs of social life, may mitigate those costs.