Feeding competition and predation risk are two important factors determining female reproductive success and interfemale relationships (Sterck et al. 1997). Although an increase in the number of individuals in a group can reduce the predation risk for each individual, it also increases competition over food. As feeding competition directly influences female reproductive success, there may be an optimal number of females in a group depending on the social and ecological situation (Markham et al. 2015). When the number of females in a group increase, competition between females over food will also increase. Such competition over food will result in a species-specific social structure that results from struggling of females to acquire a better social position (Barton et al. 1996; Kappeler and van Schaik 2002; Pusey and Schroepfer-Walker 2013). After an establishment of social structure, the social structure will then stabilize how local resources are distributed to females and influence fitness of each female. For example, increased contest competition over food may result in a more linear hierarchy that may reduce one’s fitness in a lower hierarchy as it will reduce the chance of access to food to them (Sterck et al. 1997). In such a group, group females may not be able to utilize the maximum local carrying capacity as resources will be distributed unequally and may result in surplus and scarcity for individuals in different hierarchies. On the other hand, if females are tolerating each other, so the social structure does not hinder resource allocation between females of different social ranks, this tolerant social structure may help females even in a lower social rank utilize the local resource better (Hamilton et al. 2009)