Lip smacking is associated with affiliative behavior. Vocal communications are thought to communication specific information about the environment. Estrus cycles run roughly 30-35 days. Gestation time can run from 170-190 days with most falling around 180 days. Infants are born throughout the year though are especially numerous in October through December in South and East Africa.
Available resources seem to play a role in both conception and outcome.
More conceptions occur when there is a better food supply. One study of olive baboons showed that more males were born if there was less rain in January. Infants inherit their mothers' ranks and rank also seems to play a role in conception and outcome. Higher ranking yellow baboon females conceive earlier and have more female infants and a lower infant mortality rate. High ranking mothers are more permissive than low ranking, who tend to keep their infants close.