Measuring stress in wildlife: techniques for quantifying glucocorticoids

Sheriff and colleagues reviewed how glucocorticoid hormones are measured to assess stress in wild and captive animals, covering blood, faecal, urinary, salivary and hair sampling. They discussed the strengths and limitations of each matrix, the importance of validation and appropriate interpretation, and the distinction between acute and chronic stress signals. The review cautioned that elevated glucocorticoids are not simply equivalent to poor welfare, since the hormones serve normal adaptive functions, and that context and baselines are essential. It became a widely used methodological reference for stress physiology, including felid welfare studies that depend on non-invasive cortisol measures, helping standardise how researchers quantify and interpret hormonal stress responses.