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Faecal glucocorticoid metabolite (fGCM) analysis provides a non-invasive, feedback-free approach for monitoring adrenocortical responses to natural and anthropogenic stressors. The use of enzyme-immunoassays (EIAs) to quantify immunoreactive fGCMs has gained popularity in recent years but requires species-specific validation prior to first use. We conducted a pharmacological challenge with adrenocorticotropic hormone (ACTH) to determine whether changes in circulating glucocorticoids are reflected in fGCM, concentrations and therefore to validate excreta as a matrix for monitoring endocrine status in a southern African passerine, the White-browed Sparrow-weaver (Plocepasser mahali) and a columbid, the Laughing Dove (Spilopelia capensis). We tested the suitability of four EIAs to quantify fGCMs in 10 individuals of each species. Two of the EIAs, tetrahydrocorticosterone and 11-Oxoetiocholanolone II, detected significant elevations and were therefore most suitable for quantifying fGCMs in the White-browed Sparrow-weavers. In contrast, the 5α-pregnane-3β, 11β, 21-triol-20-one EIA detected the highest elevations in fGCM concentrations in the Laughing Doves. The lag time between stressor initiation (ACTH injection) and the resulting peak fGCM concentrations was ~2 h in both species. The validations presented here open opportunities for monitoring physiological responses in free-ranging individuals and contribute to our knowledge of the EIAs suitable for non-invasive quantification of avian fGCM concentrations. [ABSTRACT FROM AUTHOR]

Leopards Panthera pardus are classified in the IUCN Red List as Vulnerable, primarily due to habitat loss, natural prey base depletion and exploitation caused by various anthropogenic activities. Although protected areas are important for leopard conservation, the majority of suitable leopard habitat lies beyond protected area boundaries exposing individuals to different environmental, physiological and psychosocial stressors. This study aimed to examine the suitability of five different enzyme immunoassays (EIAs) for monitoring adrenocortical function in the leopard based on faecal glucocorticoid metabolite (fGCM) analysis. After performing an adrenocorticotrophic hormone (ACTH) stimulation test and investigating the stability of fGCM post-defaecation, faeces from free-ranging leopards in a peri-urban and a conservation area were collected to investigate the potential impact of habitat variability on glucocorticoid output. An EIA measuring fGCM with a 5-3-11-diol structure performed best, demonstrating a 200%-330% increase in fGCM concentrations approximately 40 h post-ACTH administration. Concentrations of fGCM remained quite stable for up to six days post-defaecation and showed a maximum increase of 8% and a maximum decrease of 9%. Although not significantly different, overall median fGCM concentrations were 68% higher in individuals utilising the peri-urban area compared with leopards utilising the conservation area. The ranges of fGCM concentrations between sites, however, were similar. Individual median fGCM concentrations differed distinctly between free-ranging males and females, possibly linked to female reproductive status. The established method can now assist in addressing some of the issues facing local wildlife managers, conservationists and researchers tackling various aspects related to leopard conservation and management under different land-use practices. [ABSTRACT FROM AUTHOR]