Mountain refugia limit anthropogenic suppression in a re-established felid population: the case of the Magaliesberg leopard population in South Africa

Abstract

Although highly adaptable, leopards incur substantial mortality in human-modified landscapes and generally subsist at lower densities than in protected areas. Leopard populations are difficult to enumerate across any landscapes, though there have been strides to improve upon this, particularly in South Africa. This study aimed to determine the population density of leopards in the Magaliesberg mountain range of the North West province in 2015 and provided a longitudinal comparison of these camera-trapping sites. It appraises the efficacy of interventions aimed at improving the status quo of zero leopards found during a prior survey in 2011. Such interventions included a moratorium on sport hunting of the species, and the reintroduction of four individuals, two of each sex, into this area. Camera trapping over 10 months detected seven unique individuals, including one juvenile and six adults, consisting of four males and three females, half of which were previously reintroduced or progeny thereof. A Bayesian capture-recapture abundance model indicated a population of 5–7 individuals occurring within 1 480 km² of available habitat, yielding a density estimate of 0.34–0.47 adult leopards per 100 km², which is a relatively low estimate, likely due to population suppression from anthropogenic pressures surrounding the site (i.e., snaring). This study demonstrates that large carnivore populations can recolonise their former range via targeted interventions within topographical refugia.