Feather Hormones as Noninvasive Biomarkers: Assessing Stress and Metabolic Status in The Endangered Pyrenean Capercaillie (Tetrao Urogallus Aquitanicus)

Dr. Anaïs D. Laurent, Dr. Mateo S. Cruz, Dr. Julia R. Finch — Tue, 23 Sep 2025 00:00:00 +0000

Background: The Pyrenean Capercaillie (Tetrao urogallus aquitanicus) is a critically endangered subspecies facing significant threats from habitat degradation and human disturbance [4, 24]. Assessing the physiological stress and metabolic status of this elusive bird is crucial for effective conservation, yet traditional methods are highly invasive. This study explores the utility of noninvasive feather analysis to assess circulating levels of corticosterone (CORT), a primary stress hormone, and triiodothyronine (T3), a key regulator of metabolism and thermoregulation.

Methods: We collected naturally molted feathers and feathers from sedated birds across the Pyrenees. We adapted and validated established protocols for the extraction and quantification of CORT and T3 from the feather matrix using ELISA. Statistical analyses, including linear mixed models, were used to examine the relationships between feather hormone levels and a range of seasonal and environmental variables.

Results: Our analysis successfully demonstrated the feasibility of simultaneously quantifying both CORT and T3 from the same feather sample. Preliminary results indicate significant seasonal variations in CORT and T3 levels, with increased CORT concentrations observed in areas with high human activity. We also found a strong correlation between feather T3 and seasonal temperature fluctuations, highlighting its role in thermoregulatory responses.

Conclusions: Feather-based hormone analysis offers a powerful, noninvasive tool for monitoring the physiological state of the Pyrenean Capercaillie. The findings suggest that human disturbance may be a significant source of chronic stress for the species, while T3 levels provide valuable insights into its metabolic and thermoregulatory adaptability. This method holds promise for providing essential data to guide conservation management, enabling a more targeted approach to protecting this endangered subspecies.

International Journal of Multidisciplinary Research and Studies

Feather Hormones as Noninvasive Biomarkers: Assessing Stress and Metabolic Status in The Endangered Pyrenean Capercaillie (Tetrao Urogallus Aquitanicus)