Document Type


Date of Degree Completion

Spring 2018

Degree Name

Master of Science (MS)


Primate Behavior

Committee Chair

Jessica A. Mayhew

Second Committee Member

Lori K. Sheeran

Third Committee Member

John B. Mulcahy


This thesis is composed of two journal-ready articles and an accompanying appendix with additional data and interpretation. Overall, this thesis describes and statistically analyzes dominance relationships in two nonhuman primate groups with novel methods, possible correlations between dominance and testosterone, and uncovers the prominent connection of caregivers to captive chimpanzee social networks. Chapter I addresses current and past variability in behavioral measures and statistical methods to derive dominance rankings. I propose a novel approach to using existing statistical techniques to analyze dominance ranks, context-dependent dominant structures (agonistic competitions, lack of agonism, privileged role, priority access to resources), the reliability of statistical analyses (DS, I&SI, ADAGIO, PERC, Elo), and rank predictability of dominance structures on other social behaviors in captive chimpanzees and wild Tibetan macaques. These results indicated context-dependent dominance and individual social roles in the captive chimpanzee group, one broadly defined dominance structure in the Tibetan macaque group, and high within-context analysis reliability but little cross-context predictability. Chapter III expands on the current literature on captive chimpanzee social networks but consider their human caregivers as potential social partners. By analyzing these social networks through multiple social network analyses, our results indicated that human caregivers occupy prominent positions (rather than peripheral or isolate) in the chimpanzees’ social network. I propose that the caregivers’ prominent position may be due to their use of chimpanzee-typical behaviors in their daily husbandry routines and interactions. Our results bear influence on captive welfare, health, translocation, and husbandry protocols across many nonhuman primate captive settings. Chapter IV investigates possible relationships between testosterone and dominance rank in the captive chimpanzee group. These results provided no statistically significant evidence to support that individual fecal testosterone levels positively correlate with context-dependent dominance ranks. The lack of significant correlations between dominance and testosterone opposes the results of other authors but supports other evidence that the interplay between behavior (specifically, aggression) and hormones (specifically, testosterone) is complex and can become convoluted by multiple extraneous variables.