Quantification of faecal glucocorticoid metabolites as a measure of stress in the rock hyrax (Procavia capensis) living in an urban green space

Despite the abundance of rock hyrax (Procavia capensis) within South
Africa's urban areas, there is not much information available about
the effect of anthropogenic activities on rock hyrax wellbeing. To
determine the potential impact of anthropogenic disturbance on
adrenocortical activity, we conducted an ACTH challenge to identify a
suitable enzyme-immunoassay (EIA) for measuring faecal glucocorticoid
metabolite (fGCM) concentrations in the rock hyrax. This study identified
an 11β-hydroxyaetiocholanolone EIA as the most suitable assay in this
regard. The fGCM levels measured, indicate the physiological stress
response in different rock hyrax populations, living in an area with
varying degrees of anthropogenic activity (low, medium, high) within the
National Botanical Garden of Pretoria, South Africa. The species’
habituation to human numbers (weekly mean number of people) was examined
by determining individual flight initiation distance (FID). Seasonally,
there were overall higher fGCM concentrations in late spring compared to
winter. The fGCM concentrations, although not significantly
different but possibly biologically relevant, in the section with the
lowest anthropogenic disturbance were ~10% higher compared to those in the
section with medium disturbance, and ~20% higher compared to those in the
section with the highest disturbance. Animal FID did not differ
significantly between seasons but they did differ significantly between
sections, and decreased in accordance with fGCM concentrations. The
non-invasive approach established in this study provides a foundation for
assessing rock hyrax wellbeing, and can help better understand how
anthropogenic presence is perceived as a stressor in this species.