The males of a troop compete intensely for status and access to females. A female has an oestrous cycle of 30-35 days, and for about 2 weeks around the time of ovulation she displays a pink sexual swelling. She may mate promiscuously, but at the time of ovulation, she tends to form a consortship with a single mature male, or with several in succession. If she becomes pregnant, she has no further swellings, but her bare bottom becomes a deep, bright pink color. Her baby is born after 6 months, and at first it has pink skin and black hair.
Black infants are the focus of great interest, particularly from females but also from adult males.
Baboons will not attack familiar black infants, so the male holding the baby may thus prevent other males from attacking him. At 7 months the infant's coat turns brown, and weaning occurs during the second year. Soon after the infant reaches two, the mother's next baby is born. Juveniles play tirelessly, with each other and sometimes with young chimps, and in beach troops they seem to enjoy playing in shallow water. Baboons can live for about 25 years.