Validation of a non-invasive assessment technique for quantifying faecal glucocorticoid metabolite concentrations in the short-beaked echidna (Tachyglossus aculeatus)

Abstract

The monotreme adrenocortical response to stress may not rely as heavily on the hypothalamic–pituitaryadrenal (HPA) axis compared to other mammals. This study aimed to validate a technique in which glucocorticoid metabolites could be quantified non-invasively in short-beaked echidna faeces by examining the secretion of glucocorticoids (GC) using an adrenocorticotrophic hormone (ACTH) challenge on sexually mature captive echidnas. Echidnas were housed individually for 15 days, with the ACTH challenge occurring on day five. Blood samples were collected on day five during the challenge and faecal samples were collected each morning for the 15 days. Both sample types were analysed for glucocortic..