Indigenous Knowledge and Biomarkers of Physiological Stress Inform Muskox Conservation in a Rapidly Changing Arctic
Date
2020-12-11
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Abstract
Glucocorticoids play a key role in energy regulation and are mediators of the physiological stress response in mammals. Their concentrations are commonly measured in wildlife to understand the effects of environmental changes and anthropogenic disturbances, but their use is associated with multiple challenges and there is a need for species-specific validation. Muskoxen (Ovibos moschatus) are an essential part of the Arctic ecosystem, where they have a strong economic, nutritional, and sociocultural value for Indigenous communities. Recent population declines and mortality events suggest that muskoxen may be threatened by the multiple environmental changes and associated stressors to which they are increasingly exposed. Overall, I sought to establish fecal glucocorticoid metabolites (FGM) and qiviut (woolly undercoat) cortisol as biomarkers of physiological stress in muskoxen, and to apply these tools together with Indigenous knowledge (IK) to explore potential causes and patterns of physiological stress in wild muskoxen. Through two repeated pharmacological challenges in captive muskoxen, I showed that qiviut cortisol and FGM levels accurately reflect long-term (over the period of the hair’s growth) and short-term changes in circulating cortisol, respectively. I also demonstrated that changes in circulating cortisol are not reflected in qiviut in the absence of growth and highlighted variations across body regions, significant differences in qiviut segments over time, and differences between shed and unshed qiviut. Additionally, I documented IK which provided novel insights on the potential stressors of muskoxen and their specific importance. Finally, I identified important factors influencing qiviut cortisol (sex, geographical location, season, and year), and found associations between qiviut cortisol and marrow fat and lungworm intensity. Findings were interpreted in part collaboratively with IK holders. This work has advanced our understanding of glucocorticoid deposition and stability in hair, and of the limitations and challenges associated with hair glucocorticoid interpretation. It has highlighted the multiple benefits of incorporating IK in wildlife endocrinology studies and provided a framework for doing so. Finally, identifying factors associated with qiviut cortisol is a key step to simultaneously investigating the causes and consequences, both at the individual and population levels, of physiological stress in muskoxen.
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Keywords
Arctic, Muskox, Ovibos moschatus, Stress, Indigenous knowledge, Fecal glucocorticoid metabolites, Hair cortisol, Adrenocorticotropic hormone, Widlife
Citation
Di Francesco, J. (2020). Indigenous Knowledge and Biomarkers of Physiological Stress Inform Muskox Conservation in a Rapidly Changing Arctic (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.