Density of the Vulnerable Sunda clouded leopard Neofelis diardi in a protected area in Sabah, Malaysian Borneo

Population density is an important parameter for monitoring and guiding conservation of small or threatened wildlife populations. Yet, despite the Vulnerable status of both species of clouded leopard Neofelis spp., and their disappearing tropical forest habitat, information on their population density is lacking from across their broad geographic ranges. Here we estimated population density of the Sunda clouded leopard N. diardi in the Maliau Basin Conservation Area in Sabah, Malaysian Borneo, one of the first such estimates for either species of clouded leopard. With 25 camera-trap stations, each operated for at least 81 trap-nights, we obtained 59 detections of four individual Sunda clouded leopards in undisturbed primary rainforest but only a single detection in logged forest, despite similar sampling effort. Using spatially-explicit mark-recapture models, we estimated a density of 1.9 individuals per 100 km(2) (95% confidence interval 0.7-5.4) for primary forest and 0.8 per 100 km(2) (0.2-2.6) for the entire study area (including logged forest). These results will contribute to a better understanding of clouded leopard status and serve as a reference for future assessments of the species.