The importance of refugia, ecological traps and scale for large carnivore management

Abstract

Management zones feature prominently in conservation planning, particularly at large spatial scales, but prioritization of areas of concern is required to focus efforts and limited resources. Human-mediated mortality constitutes a major threat to species persistence, particularly for widespread carnivores that undergo harvest and population control, such as the leopard (Panthera pardus). In this study, we evaluated the extent and spatial distribution of legal anthropogenic offtake of leopards to identify de facto refugia and ecological traps across Limpopo Province, South Africa. We defined refugia as management units with offtake levels below an established sustainable harvest rate, and ecological traps as management units with offtake exceeding the sustainable harvest rate. We assessed offtake at three geographical scales using trophy hunting permit records alone, and then in combination with problem leopard permit records to investigate the compounding effect of additional forms of offtake and the potential for management scale mismatching. Across Limpopo Province, high leopard offtake created fewer areas of refuge than ecological traps. Refugia were smaller in size and within close proximity of ecological traps. Human-mediated leopard mortality occurred mostly in prime leopard habitat. Finerscaled management units resulted in fewer ecological traps and more refugia, and enables authorities to focus conservation attention in areas of concern. Human-mediated leopard mortality exceeded the annual offtake rate considered sustainable. Our study highlights the importance of assessing both the scale and distribution of the harvest, whilst also considering alternative forms of offtake, when devising harvest management strategies. Management scale mismatching and high human-mediated leopard mortality is of particular concern in Limpopo Province, as such, we propose an adaptive, science-based regulatory framework aimed at improving leopard harvest strategies.