Evidence of a high-density brown hyena population within an enclosed reserve: the role of fenced systems in conservation

Abstract

Small, enclosed reserves are now common across Africa, and their conservation importance as wildlife refuges is increasingly acknowledged. Whilst such reserves represent areas safe from human persecution, they can also become threats themselves when the natural processes of emigration and immigration are prohibited. As a result, wildlife populations residing in enclosed reserves require careful management to safeguard their long-term persistence. As successful conservation management relies on precise population estimates, we estimated brown hyena density within a 180-km2 enclosed reserve in north-central Namibia. Using camera trapping methods in combination with spatially explicit capture-recapture (SECR) models, brown hyena density was estimated at 24.01 brown hyenas/100 km2 (± 3.47, 95% CI’s 18.12–31.81), the highest recorded to date for the species. The high density is attributed to the relatively high density of leopard within the reserve, which may facilitate brown hyenas by providing access to the large herbivore biomass through kleptoparasitism, coupled with protection from human persecution. Results highlight the potential for enclosed reserves to host high-density populations of a persecuted large carnivore and show that, despite their often small size, such systems can aid conservation efforts. However, such results suggest reserve managers will be increasingly faced with the dilemma of dealing with surplus individuals when populations exceed carrying capacity. Therefore, the development of methods estimating carrying capacity for scavenging species, along with creating meta-population management schemes for all large carnivore species are essential next steps for conservation in Africa.