Comparing behavioral activities of male and female adolescent macaques

Behavior of males and females may be mediated by their biological differences and, among cercopithecines, their divergent reproductive strategies. In order to have high reproductive success, individuals need to produce high quality offspring. Through pregnancy, lactation, and maternal care, females have a strong influence on the quality of their offspring. Within the cercopithecine mating system, males are limited in direct influence on offspring outcomes within the Cercopithecines, and are adapted to more typically maximize mating opportunities. In general, female reproductive strategies involve securing the most food while male reproductive strategies are geared towards helping them secure the most fertile females both somatically and behaviorally. In this paper, I investigated how the behaviors observed among female adolescent rhesus macaque monkeys would differ from the males as their divergent reproductive trajectories begin to manifest. I made predictions based off of four questions: who would be more affiliative with whom, who would be more aggressive and with whom, who would be more variable in their behaviors, and who would be lonelier. I predicted that females would be more affiliative with other females, due to the importance of social connectivity, and males would be more affiliative with males, due to the social bonds male adolescents form with each other. I predicted that males would be overall more aggressive than males because they were found to be by Bernstein et al. (1993). I predicted that males would show more variation in behavior since they may have to be more flexible to capitalize on all conditions to obtain mates. Finally, I predicted that males would be lonelier as an effect of social rank on males and female choice. In order to further understand these differences, 36 adolescent Macaca mulatta, N = 20 female and N=16 male, from the California Primate Center at University of California at Davis, CA were observed. The observer used a standardized method to score the subjects on a variety of behaviors like locomotion, aggression, grooming and more. Each individual underwent around 6 trials and the observations lasted 15 minutes. The data supported the first hypothesis that females are affiliative with each other and males are affiliative with each other. The date also showed that females are more aggressive than males and their aggression is generally targeted towards females. The third prediction was not supported by the data and females were actually more variable in their behaviors than males. Lastly, the data did not support the prediction that males are lonely moneys, however, it did support the alternative hypothesis that they are truly low sociable, low in sociability and low social connectivity.