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Introduction

The order Primates is comprised of individuals that share morphological traits such as front facing eyes, opposable thumbs, and a more complex brain. Species within this order also tend to be highly social. In many cases, individuals spend their lives living in social groups. The general structure of these groups varies from species to species with different ratios of males and females observed within a community. The benefits of this social structure include a greater ability to dominate local resources through group foraging and a greater ability to defend against predators (Majolo et al. 2008). One species that is observed to live in a social structure is Cercopithecus petaurista or Lesser Spot-Nosed Guenon which features a polygynous hierarchy, with one dominant male and several females. The male is typically the most dominant individual within the social group, maintaining order and defending against predators (O'Neil 2012). The females of the group also fall under a hierarchy, but are almost always hold a social status below the male.

In studies on C. petaurista and other species under the same genus, it appears that the position of a female in the hierarchy can be determined by observing behaviors in grooming and aggression incidents. Studies such as Struhsaker's on C. aethiops and Cheney's on various Cercopithecus species observed that the social rank of female members of a community had direct influence over the competition over grooming with male partners (Struhsaker 1967). It is also important to note that individuals on the lower end of the social hierarchy are more likely to groom other members of the community than they are to receive grooming since individuals at the top of the hierarchy have to maintain an identity of being a high-ranking member of society (Chiarelli 1980). This phenomenon has a direct influence on the overall health of individuals across the social hierarchy. Those holding lower social statuses are at a higher risk for several health issues since receiving grooming has a positive effect on immune system strength (Caruso 2016). When analyzing the immune cells of monkeys at different positions within a hierarchy, individuals towards the top of the hierarchy had a higher T-cell count and, as a result, were better equipped to respond to disease (Snyder-Mackler et al 2016). Struhsaker also notes that aggression over special positioning and food resources was commonplace when both resources were in limitless supply. Dominance can be traced through which individual successfully won these resources in agonistic fights.

The goal of this study is to expand upon these observations on the social dynamics within the Cercopithecus genus to determine if this behavioral trend persists within a community living in captivity. Accordingly, agonistic fights and social grooming behavior were observed to determine if they are both influenced by the social rank of an individual and if they can help determine the social hierarchy of a captive C. petaurista community. This information will help increase the quality of care for C. petaurista communities in captivity since understanding the full effect hierarchy status holds over individuals allows keepers and management to deal with the various issues faced by community members at different social ranks.

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