Seasonal breeding in rhesus monkeys: Influence of the behavioral environment.

The accepted model of breeding seasonality in rhesus monkeys states that females become reproductively active in response to an environmental cue and that males become sexually active in response to ovulating females. This model must be modified to include direct responses of the male to the physical environment, endocrine responses of males to sexual activity, and responses of the female to the sexual activation of fellow group members. The complex set of social stimuli that influences the breeding readiness of both sexes may serve to delimit more precisely the annual periods of conception and birth than would be the case if each individual responded only to the changing physical environment.