Mating patterns and social structure in a wild group of Formosan macaques (Macaca cyclopis)

Understanding the patterning of male-female relationships throughout the reproductive cycle provides a foundation for looking at questions of mate choice and mate competition. Adult interaction patterns and reproductive behavior were studied in a wild, un-provisioned, multi-male group of Formosan macaques (Macaca cyclopis). Female Formosan macaques remained in their natal group excepting one juvenile female who immigrated into a group. Juvenile males emigrated at 3.5 to 5.5 years old. Males and females had linear dominance hierarchies and males were individually dominant to females.; Formosan macaques showed distinct reproductive seasonality. The number of male copulations was positively correlated with male dominance rank. Female sexual swellings were present but there were large individual differences in swelling height. Females emitted loud, distinct copulatory vocalizations. More than 98% of all observed copulations involved a call by the female. Males called during 18% of all observed copulatory mounts. The alpha male made most of those calls. Lower ranking males were observed to suppress these calls.; Temporal variation in grooming, proximity, and aggression patterns between males and females in this seasonally breeding species were analyzed. Ninety percent of all male-female grooming occurred during the mating season, mainly among mating pairs. Proximity measures showed a similar pattern. Male aggression toward females was highest during the mating season. Male-male aggression was also high during this time. Resident males were most aggressive towards extra-troop males and formed coalitions against them. An aggressive male takeover was observed. It involved three separate sets of male-male alliances.; This study has contributed to current models of the relationship between mating strategies, social structure, and social organization. Field research on primates that live in forests are under-represented in the literature and studies on wild Formosan macaques are much less common. This research will also aid the Taiwanese agencies, that are entrusted with the conservation of endemic species like the Formosan macaque, work toward preserving healthy populations of this vulnerable species.