Analysis of tufted capuchin (Cebus apella) courtship and sexual behavior repertoire: changes throughout the female cycle and female interindividual differences.

Sexual solicitations and initiative (proceptivity, sensu Beach [1976] Horm Behav 7:105-138) are important components of the sexuality of females of many primate species. In the tufted capuchin (Cebus apella), female proceptivity characterizes the species' mating system. In study 1, we defined and discussed 20 behavioral patterns based on the observation of 6 females and 5 males living in two social groups. In study 2, each behavior, including mounting activity, was quantitatively assessed during the periovulatory and nonperiovulatory cycle phases of 4 females, detected on the basis of urinary progestin levels (N = 20 ovulatory cycles, 5 for each female); moreover, we monitored changes in females' social interactions (agonism, grooming activity, and play). Nine of the behaviors typically used by the female during courtship and in sexual interactions showed a dramatic increase during the periovulatory phase. Though males mounted females at an apparently higher rate during the periovulatory than the nonperiovulatory phase, the difference was not significant. However, when adult male mounting is separated into those which occur within play and nonplay contexts, there is a significant periovulatory phase effect for mounts not associated with play. Females groomed adult males at the same rate throughout the cycle. Agonism and play did not show any phase effect; however, females' avoidance of adult males significantly increased during the periovulatory phase. Finally, each female made a statistically different use of the behavioral repertoire by performing some behaviors more than others. This variability among females during courtship calls for further research into whether it affects mating success.