Broadly, my research interests focus on endocrinology, behavior, sociality, health, welfare, and conservation of nonhuman primates. I am interested in addressing questions of how life history variables and early life conditions impact adult primates through physiological changes, and in turn how physiology is moderated by behavior and social dynamics. Additionally, my research focuses on exploring how physiology translates to future health outcomes, which can be either ameliorated or exacerbated by behavior and social connectedness, depending on the individual and the circumstances.
While all aspects of endocrinology are of interest, my research specifically is aimed toward developing and applying allostatic load indices in nonhuman primates. Allostatic load is the physiological impairment or wear-and-tear individuals accumulate over the lifespan due to experiencing stressors. Allostatic load indices are composites of physiological biomarkers from throughout the entire body (e.g., cortisol, cholesterol) that are combined to give a score representing an individual's overall allostatic load. These allostatic load indices have been used for two decades in humans and have been shown to predict individuals at greatest risk of poor future health (for a review of allostatic load research, please see my papers in Yearbook of Physical Anthropology and Journal of Zoo and Wildlife Medicine). Previously, these indices were only applied to humans but the stress response is conserved in primates (this means that the way the stress response works is similar across different species of nonhuman primates). Great apes share with us physiological, behavioral, and genetic similarities, including a tendency to develop the same chronic degenerative conditions (e.g., heart disease, arthritis), facilitating the application of allostatic load indices to our closest relatives.
Through my research with zoo-housed western lowland gorillas (Gorilla gorilla gorilla), I have developed and analyzed the first allostatic load indices for a nonhuman species. My dissertation, “Assessing Long-Term Stress in Great Apes: Allostatic Load in Western Lowland Gorillas (Gorilla gorilla gorilla),” explored how various life history and demographic variables contribute to physiological dysregulation, or allostatic load, and in turn how that physiological dysregulation associates with negative health outcomes. Several predictors of allostatic load were identified, including older age, type of stressful events experienced, parity, and alternative rearing history, which is analogous to early life adversity in humans. I also observed several significant associations between higher allostatic load and measures of health, including traditional veterinary indicators of morbidity (e.g., triglycerides), the presence of at least one chronic degenerative disease, and mortality risk. My research demonstrates allostatic load indices, which were previously only applied in human research, are useful models for investigating questions of stress and health among great apes. To read more about my research with gorillas, check out my Publications and Featured Research.
My ongoing research with gorillas is focused now on exploring how behavior and social connectedness are associated with future health via allostatic load. In the future I will be extending the initial allostatic load indices developed in my work with gorillas through both biomarker discovery (i.e., are there better biomarkers than the ones used in the preliminary indices?) and comparative research in other primate species. As such, I am currently developing and analyzing the first allostatic load indices in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) as a postdoctoral fellow at the Smithsonian Conservation Biology Institute. In addition to investigating how behavior and social connectedness influence allostatic load, I also will be exploring the association between allostatic load and social status/dominance rank in these species. I will be sharing data from this research as soon as they are available!
In general, stress responses are homologous throughout vertebrates, suggesting allostatic load theory and methodology may be applicable across a wide variety of taxa. This research may be valuable to wildlife veterinarians, zoo staff, and conservation scientists as a standard method for assessing stress and its effects as well as the impacts of anthropogenic factors and management changes. Allostatic load indices have the capacity to revolutionize our understanding of animal welfare and our ability to reduce stressors, increase health, and lengthen lifespan among species in human care.