Feeding is essentially an individual activity, but after a cooperative hunt may share morsels in response to begging by others. Females in heat have prominent swelling of the pink perineal skin, lasting two to three weeks or more, and occurring every four to six weeks. Males have relatively huge testes. Puberty in both sexes occurs at about seven years, but males are not fully integrated into the social hierarchy until 15 or so. Females raised in captivity begin mating at eight to nine years and give birth for the first time at 10-11 years old.
Wild females mature three to four years later.
There is no breeding season. Chimpanzee females are not receptive for three to four years after giving birth, then resume sexual activities for one to six months until conception. Females mate only when in heat. For the first week or more, female chimps are promiscuous and mate on an average of six times a day. Toward the last week of estrus, when ovulation occurs, high ranking males may compete for mating rights.