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.
