Population density estimates of spotted hyaena (Crocuta crocuta) in two KwaZulu-Natal protected areas

Despite increasing recognition of the important
ecological role large carnivores fulfil and their ability to generate income
for protected areas, they remain amongst the most threatened species on Earth.
Most large carnivore species have exhibited substantial population declines and
geographic range contractions during the past two centuries. Key to reversing
this trend is devising cost-effective monitoring methods that produce reliable
estimates of abundance or density over timeframes that allow for the success or
failure of conservation interventions to be measured. As both scavengers and
apex predators, spotted hyaenas (Crocuta crocuta) play extremely
important ecological roles, and it has been suggested that they are keystone
predators and key indicators of ecosystem health. Although the IUCN Red List of
Threatened Species lists spotted hyaenas as “Least Concern”, the overall
population trend is decreasing and regional declines have been observed in some
areas, such as the northern KwaZulu-Natal province of South Africa. Habitat
loss and direct persecution are causing spotted hyaenas to become increasingly
reliant on protected areas. In my study, I analysed hyaena by-catch data from
camera trap surveys that were conducted in 2019 to monitor leopards (Panthera
pardus) in two protected areas in northern KwaZulu-Natal, Mun-Ya-Wana
Conservancy and the uMkhuze section of iSimangaliso Wetland Park. I used
spatially explicit capture-recapture (SECR) models to estimate the population
density of spotted hyaenas in both protected areas. The density of spotted
hyaenas in Mun-Ya-Wana Conservancy was estimated to be 5.86 ± 1.12 individuals
per 100 km2, based on 30 identified individuals in a sample area of
3122 km2. The density of spotted hyaenas in the uMkhuze section of
iSimangaliso Wetland Park was estimated to be 2.97 ± 0.79 individuals per 100
km2, based on 26 identified individuals in a sample area of 2828 km2.
These results confirm both the importance of new protected areas (Mun-Ya-Wana
Conservancy) in reversing population declines while simultaneously showing that
long established protected areas (uMkhuze section of iSimangaliso Wetland Park)
may be failing to protect spotted hyaena and presumably other large carnivores.
Understanding the drivers of these differences between protected areas is
essential to provide regionally stable spotted hyaena populations. Routine
camera trap surveys combined with SECR models provide a cost-effective way to
monitor spotted hyaena populations and produce reliable estimates of population
density. Once more accurate, long-term data on the size and trends of spotted
hyaena subpopulations both within and outside protected areas have been
collected, the status of spotted hyaenas should be reassessed.