Spatial constraints and seasonal conditions but not poaching pressure are linked with elevated faecal glucocorticoid metabolite concentrations in white rhino
DATA AVAILABILTY : The data that support the findings of this study are available from the Science Manager at South African National Parks Mrs Judith Botha
([email protected]), upon reasonable request.CONTEXT : Due to considerable declines in African wildlife populations, most large African mammals
are managed inside protected areas. Protected areas come in various sizes, and have different
environmental features, climates and management strategies (i.e. ‘hands-on’ or ‘hands-off’) that can
influence an animals’ homeostasis. White rhinos (Ceratotherium simum simum) are found almost
exclusively within protected areas where population sizes are driven by natural factors and
poaching pressures. AIMS : Our aim was to understand the effect of natural and anthropogenic
factors on the adrenocortical response of white rhinos within three protected areas. Specifically,
we wanted to understand how poaching pressure, protected area size (<500 km2), season (wet
and dry) and rainfall patterns were responsible for driving adrenocortical activity in white rhino.
METHODS : To understand the relationship between rhino adrenocortical responses and different
environmental and anthropogenic stressors, we quantified glucocorticoid metabolites in faecal
samples (fGCM) collected from four populations within three protected areas (i.e. two small
parks, one big park) during the wet and dry seasons. KEY RESULTS : We found differences in
seasonal fGCM concentrations, with a 42% increase during the dry season, and no differences in
fGCM concentrations between the high and low poaching areas. Additionally, we found fGCM
concentrations in samples from the small parks were respectively 38% and 42% higher than in
samples from the large park during both the dry and wet seasons compared. CONCLUSIONS : Our
results suggest that white rhinos may experience physiological stress in smaller parks, especially
during the dry season when resources are limited. IMPLICATIONS : By mitigating stress associated
with reduced access to resources and spatial constraints, managers may better promote the
viability of large mammals in small protected areasThe South African National Parks.https://www.publish.csiro.au/WRhj2023Mammal Research Institut