Individual copulatory preference and the

Abstract

The common chimpanzee has been considered to be a promiscuous species, although transient consort relationships and male possessive behavior have been described by Tutin (1975, 1979).

A prolific adult male chimpanzee was housed with from 4 to 7 adult female chimpanzees (depending on the females' maternal status) and copulations were recorded from 8/7/78 until 2/16/79, during morning feeding periods. Ten females composed the fluctuating available partners.

These data suggest that the male chimpanzee can form an individual mating preference regardless of the hormonal status of his available partners without lessening his reproductive success with nonpreferred females, but maximizes his reproductive success by copulating with novel females.

Sixty-four observed copulations involved 6 females. One S was clearly preferred, including occasions when she was not maximally tumescent (e.g., completely detumescent, pregnant) and other available females were maximally tumescent. The remainder of the observed copulations, with 1 exception, involved females who had recently been reintroduced into the one-male breeding group. Such copulations took place on and continued temporarily after the day of reintroduction for 2 females, and after the resumption of menstrual cycling for 2 females who had been reintroduced while still lactating. Non-preferred females were impregnated during the period of data collection, even though copulations with them were not observed.