Estimating large carnivore populations in an arid fenced reserve using spatial capture–recapture modelling

Fencing has become a critical tool in large carnivore conservation in South Africa, mitigating human-wildlife conflict and habitat fragmentation. However, reliable population density estimates for large carnivores in fenced, arid environments remain scarce. This study addresses this gap by conducting a single-season camera trap survey in the Tswalu Kalahari Reserve (hereafter Tswalu), South Africa. Using spatial capture-recapture (SCR) models, we estimated leopard (Panthera pardus) density at 0.18/ 100 km² (± SE 0.09), among the lowest reported in fenced systems and comparable to densities in unfenced arid systems. Only 21.18% of camera traps detected leopards, suggesting factors limiting their distribution or recovery in Tswalu. In contrast, brown hyaena (Parahyaena brunnea) density was estimated at 3.1/ 100 km² (± SE 0.51), the highest estimate for the arid Northern Cape province, exceeding densities in mesic environments but lower than those from arid fenced reserves in Namibia. Spotted hyaena (Crocuta crocuta) density was 0.66 / 100 km² (± SE 0.25), the second lowest across fenced African systems and the first estimate for the Northern Cape. This study provides critical baseline data for carnivores in an underrepresented arid system, highlighting the importance of density estimates for informing conservation strategies. We recommend expanding camera trap surveys onto adjacent unprotected private lands and other key Northern Cape conservation areas to assess carnivore presence beyond Tswalu’s boundaries, combined with continued annual monitoring within Tswalu. Ongoing SCR studies across South Africa’s fenced reserves are crucial for strengthening evidence-based conservation and management planning for large carnivores in arid habitats.