Graduate Student Highlight: Kristena Cooksey

Kristena Cooksey is a biological anthropologist pursuing her doctoral degree at Washington University in St. Louis. Using noninvasive approaches to study the behavior and physiology, her dissertation research focuses on the interplay between sociality, stress, and health in western lowland gorillas (Gorilla gorilla gorilla) in northern Republic of Congo. More specifically, she is examining the association between social position and stress, assessing the impact of encounters between gorilla groups on stress profiles, and determining the relationship between sociality, stress, and health in gorillas. By comparing these results to gorilla populations residing in zoos, this research will offer insights on whether or not social status and endocrine profiles are analogous across captive and wild population


Taking an integrative evolutionary approach, Kristena has selected the western lowland gorilla as a model species to examine the stress response and its relationship to health status and social interactions. These apes are ideal study subjects because they live in social units of various compositions with linear dominance hierarchies, reside in highly seasonal environments, and frequently intersect with other groups who share their home range. Until recently, little was known about the behavior and ecology of western lowland gorillas because few groups were habituated to human presence. However, Kristena has identified an unique opportunity in northern Republic of Congo to simultaneously monitor several groups of western lowland gorillas that reside in different conservation contexts ranging from undisturbed groups to those exposed to tourism and logging.

In collaboration with the Wildlife Conservation Society’s Congo Program, Kristena traveled to central Africa to conduct a pilot study on the gorillas in the Goualougo Triangle and Mondika research sites from June to July 2016. She succeeded in collecting samples and extracting hormones for all of the group members of three habituated gorilla groups at these sites, as well as from several other gorillas in the area who were part of other breeding groups or roaming as solitary males within these areas. Subsequent laboratory analyses of these samples at the Davee Center for Epidemiology and Endocrinology at Lincoln Park Zoo validated Kristena’s pilot study protocols with intriguing individual and group differences in cortisol concentrations. In August 2016, she presented preliminary findings on rates of intergroup encounters in western lowland gorillas at the join meetings of the American Society of Primatologists and the International Primatological Society held in Chicago. Kristena plans to return to the field to continue data collection for her dissertation in August 2017.