Reproductive cycles of the talapoin monkey (Miopithecus talapoin).

Reproductive cycles of female talapoins living in caged breeding groups were followed over 7 years, using visible changes of the perineum. Changes in the perineum during the extended adolescence of this species are described. There was a clearly defined breeding season, although its onset was not so abrupt as in the wild. During the summer months females show very small perineal swellings or none at all. Even during the breeding season all stages of the follicular phase of cycles are highly variable. Completed menstrual cycles are relatively rare since talapoins are highly fertile; they may be somewhat shorter than fertile cycles. Cyclical activity is modifiable by social stimuli, and it is suggested that differences in synchrony of breeding between wild and captive populations might be due both to indequate climate cues and to a lower level of social stimulation in captivity. The concept of the menstrual cycle had limited value in predicting reproductive activity in this highly fertile seasonal breeder.