Determination of Fecal Tri-iodothyronine and Cortisol as Physiological Proxies of Animal Welfare
Grantees: Michael Cherry, Joe Hediger
Institutions: Caesar Kleberg Wildlife Research Institute, Texas A&M University, University of Massachusetts Dartmouth, United States
Grant amount: $25,860
Grant type: Small grants
Focal species: White-tailed deer (Odocoileus virginianus)
Conservation status: Least concern
Disciplines: Physiology, animal welfare science
Research location: United States
Project summary
Wildlife are susceptible to both direct and indirect effects of thermal stress imposed by a warming climate. Direct effects include increased energetic costs to maintain a healthy body temperature and immune system impairment, while indirect effects include changes in food availability and increases in disease transmission. White-tailed deer (Odocoileus virginianus) in southern Texas are on the front lines of this environmental challenge. This project aims to assess the reliability of fecal tri-iodothyronine (T3) and fecal glucocorticoids (FGC) as non-invasive physiological metrics for monitoring the health of white-tailed deer. The use of T3 as an indicator of wildlife health and welfare is relatively novel, and the researchers will attempt to refine the use of these metrics through controlled experiments, correlating the T3 measurements with a more widely used indicator in FGC. Both physiological indicators will also be validated against behavioral observations of the same deer that are thought to reflect their emotional state.
Why we funded this project
The study findings will help in understanding how wild animals cope with increasing temperatures and the impact of thermal stress on their welfare and health. Notably, previous work has suggested that T3 measurements in ungulates are especially sensitive to thermal stress, and so comparing T3 with other indicators based on different physiological pathways, such as glucocorticoids, could help researchers to diagnose the relative significance of different environmental stressors an animal is facing. The project’s behavioral metrics are also crucial for realizing that potential. A secondary reason for our interest in this project is that it has near-term policy implications, potentially highlighting the value of preserving or promoting specific landscape features for the ecosystem service they offer, in the form of shade, to wild ungulates.
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