Leopards and mesopredators as indicators of mammalian species richness across diverse landscapes of South Africa

Abstract

The rapid extinction of species over the past few decades has created a biodiversity crisis. Factors contributing to recent extirpations are linked to increased human population growth, habitat loss and fragmentation, and over-exploitation of wildlife. Only decisive, effective action to combat biodiversity loss can reverse these trends. The use of indicator species as surrogates for biodiversity provides a way to identify areas with high biodiversity so that conservation efforts can be accelerated and supported in those areas. Predators are considered important indicators of healthy, biodiverse ecosystems due to their high trophic level and their direct and indirect interaction with other species. Using camera trap data from 221 cameras set across five vegetation types and five land use zones in South Africa, we evaluated carnivores as potential surrogates for biodiversity. We used the leopard (Panthera pardus), and three meso-predators: caracal (Caracal caracal), honey badger (Mellivora capensis), and black-backed jackal (Canis mesomelas), as candidate indicator species. We used mammals captured at the camera traps as a measure of biodiversity referred to as mammalian species richness. The mammalian species richness was highest in the Orange River Nama Karoo vegetation type and in privately owned game reserves. We found that predator sightings were associated with significantly higher mammalian species richness which increased with increasing number of predator species. These findings suggest that the surrogate species concept can be applied to leopard and meso-predators.

Keywords

• Biodiversity
• Camera-traps
• Conservation
• Indicator species
• Predators
• Mesopredator