Validation by: Dr. Ronald J. Kendall. (wildlifetoxicologylab.org)
World-renowned environmental and wildlife toxicologist. Professor in the Department of Environmental Toxicology at Texas Tech University.
The researchers investigated how different sample storage conditions affect the measurement of corticosterone metabolites in northern bobwhite quail (Colinus virginianus), aiming to improve the reliability of non-invasive stress hormone monitoring in wildlife conservation research.
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Enzyme Immunoassay (EIA): An immunoassay used to quantify corticosterone metabolites in fecal samples as indicators of physiological stress in birds.
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Sample Storage Analysis: Faecal samples were subjected to immediate extraction, freezing at −20 °C for 28 days, or environmental exposure for 24 hours to evaluate how storage conditions influence hormone metabolite measurements.
Absorbance 96 was used to measure absorbance at 450 nm using the Arbor Assays DetectX® Corticosterone EIA Kit. Samples from 18 northern bobwhite quail (9 males and 9 females) were analysed to compare corticosterone metabolite concentrations across the three storage conditions.
Figure 2 compares the estimated natural logarithm (ln) of faecal corticosterone metabolite concentrations in male and female northern bobwhite quail across three storage conditions: environmental exposure for 24 hours, freezing for 28 days, and immediate extraction. Female samples showed comparable concentrations after freezing and environmental exposure, while immediate extraction resulted in significantly lower values. In males, frozen samples showed significantly lower concentrations than environmentally exposed samples, highlighting the influence of storage conditions on hormone metabolite measurements.
Results: The researchers found that sample storage conditions significantly influenced corticosterone metabolite measurements, with differences between male and female birds. Frozen and environmentally exposed samples produced comparable results in females, while immediate extraction resulted in significantly lower concentrations. In males, frozen samples showed significantly lower concentrations than environmentally exposed samples.
These findings highlight the importance of standardized sample handling for reliable stress hormone measurements in wildlife research, while illustrating how enzyme immunoassays performed using Absorbance 96 can contribute to non-invasive studies of wildlife physiology and conservation.
Publication: Suber, H. N., Leach, J., Kaskocsak, A., Valencia, H., Colette, S., & Kendall, R. J. (2025). The effects of different sample storage conditions on faecal corticosterone metabolite measurements in northern bobwhite (Colinus virginianus). Conservation Physiology, 13(1), coaf051.
DOI: https://doi.org/10.1093/conphys/coaf051
