PROCEPTIVE PATTERNS OF BEHAVIOR THROUGHOUT THE MENSTRUAL-CYCLE IN FEMALE RHESUS-MONKEYS

The reproductive behavior of captive female rhesus monkeys living in a large social group was examined to determine what patterns of proceptive behavior occur and how they are distributed throughout the menstrual cycle. Ten intact adult females and six vasectomized adult males were observed during the breeding season. The males were housed separately overnight and released into the social group for a 4-hr observation period. The female menstrual cycles were monitored by daily capture for vaginal swabbing. A total of 18 cycles in which females showed estrous behavior between intervals of menstruation were observed for nine females between October 4 and February 4. A composite of all the cycles revealed a significant rise in proceptive behavior during the follicular period culminating in a midcycle peak, with an abrupt cessation of female sexual invitations during the early luteal period. The specific patterns of proceptive behavior observed consisted primarily of female-initiated proximity and following of males. Solicitation patterns such as sexual presentation, hand slap, head bob/duck, and threat out were displayed to a lesser extent. Overall, these data suggest that underlying endocrine events strongly influence the behavior of female rhesus monkeys living in a complex social environment and that social factors such as dominance rank do not appear to override these hormonal variables. © 1979 Academic Press, Inc.