Validation of an enzyme immunoassay to measure faecal glucocorticoid metabolites from adélie penguins (Pygoscelic adeliae): a non-invasive tool for estimating stress?.

@enTo monitor adrenocortical activity in Adelie penguins (Pygoseelis adeliae), we validated an enzyme immunoassay (EIA) for faecal glucocorticoid (GC) metabolites. An adrenocorticotropin hormone (ACTH) challenge was conducted on a paired female and male. The EIA for tetrahydrocorticosterone showed a clear response to the ACTH challenge in both birds. After high-performance liquid chromatography using pooled samples generated from the ACTH challenge, and analysing each individual fraction, three immunoreactive peaks were detected. Both biological and chemical validations strongly suggest that the EIA can be a useful tool for non-invasively measuring GC metabolites in faeces of Adelie penguins.