They also prey on hares, vervets and infant gazelles. Females give birth to one infant at a time, and the average gestation length ranges from 160-180 days. Females do not mate when they are pregnant or lactating, a period of abstinence lasting about 18 mons. Once the female goes into estrous, she is receptive to males for about 2 weeks out of every 35 day period. Toward the end of this 2 week period, she may ovulate, but usually she undergoes 4 or 5 estrous cycles before she conceives.
Olive baboons live in medium to large groups with multiple males and females.
The group functions as a cohesive unit organized around a core of related females. Females usually remain in their natal groups throughout their lives, while males transfer to other groups at around the time of sexual maturity. Females maintain close bonds with maternal relatives. Adult females form linear dominance heirarchies, which remain relatively stable for considerable lengths of time. Relationships among males are usually more aggressive than those among females, perhaps because most males in a group are unrelated and because male reproductive success is largely determined by competition for females.