Leopard density in post-conflict landscape, Cambodia: Evidence from spatially explicit capture-recapture

Effective conservation of large carnivores requires reliable estimates of population density, often obtained through capturerecapture analysis, in order to prioritize investments and assess conservation intervention effectiveness. Recent statistical advances and development of user-friendly software for spatially explicit capturerecapture (SECR) circumvent the difficulties in estimating effective survey area, and hence density, from capturerecapture data. We conducted a camera-trapping study on leopards (Panthera pardus) in Mondulkiri Protected Forest, Cambodia. We compared density estimates using SECR with those obtained from conventional approaches in which the effective survey area is estimated using a boundary strip width based on observed animal movements. Density estimates from Chao heterogeneity models (3.8 +/- SE 1.9 individuals/100 km2) and Pledger heterogeneity models and models accounting for gender-specific capture and recapture rates (model-averaged density 3.9 +/- SE 2.9 individuals/100 km2) were similar to those from SECR in program DENSITY (3.6 +/- SE 1.0/100 km2) but higher than estimates from Jack-knife heterogeneity models (2.9 +/- SE 0.9individuals/100 km2). Capture probabilities differed between male and female leopards probably resulting from differences in the use of human-made trails between sexes. Given that there are a number of biologically plausible reasons to expect gender-specific variation in capture probabilities of large carnivores, we recommend exploratory analysis of data using models in which gender can be included as a covariate affecting capture probabilities particularly given the demographic importance of breeding females for population recovery of threatened carnivores. (C) 2011 The Wildlife Society.