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Grooming Solicitation & Hierarchy
in Cercopithecus petaurista

By: Ryan Domitz | Mentor: Frank Logiudice


This study demonstrates that grooming solicitation rates in C. petaurista are a more accurate metric to measure when studying hierarchy than rates of allogrooming elicited. The reintroduction event served to polarize changes in behavior, in contrast to control behaviors measured before the incident. Prior to reintroduction there was little conflict among conspecifics, and thus no known behavior associated with aggression. After Mama was reintroduced, however, it became clear that the grooming she elicited was not conducive towards placating her future aggressors. Mama's levels of grooming solicitation spiked upon reintroduction in concert with higher aggression exhibited towards her. It should thus be noted that grooming solicitation is a stationary behavior that exposes her further to such aggression.

Allogrooming rather than grooming solicitation was what I expected to be a valuable metric to gauge hierarchy and so the results were contrary to my own prediction that higher status individuals would receive higher proportionate rates of allogrooming. Measuring hierarchy in populations may serve to better understand group dynamics and to consequently better manage healthy captive groups; this task is particularly important because interpretation of the group behavioral dynamic has the capacity to be skewed due to small group size, captive setting, and any effects from inclusive fitness between half siblings like Timbi and Tumani.

Timbi's low behavioral variance may be reflective of a more stable activity budget as a consequence of his position as the dominant individual within the hierarchy of the group. Timbi is characterized by high aggression rates and low grooming solicitation rates in response to Mama's reintroduction. Timbi and Tumani's spike in aggression in response to Mama's reintroduction occurred conjointly with higher grooming solicitation rates across the enclosure, but not with higher allogrooming rates. This data are my main evidence supporting the idea that grooming solicitation has less of a relationship with allogrooming and more of a relationship with aggression rates.

To sum up, in terms of monkey identity, grooming solicitation and aggression are inversely related. In terms of the reintroduction event, grooming solicitation and aggression rates are positively related. Subject B, Timbi, is the most dominant individual in terms of aggression and solicitation; then subject C, Tumani; and lastly subject A, Mama.