Using a recently developed camera trapping method to improve monitoring efforts for African small carnivore species

Abstract

Small mammalian carnivores (here <3 kg) play an important role in ecosystem functioning and are effective sentinel species for monitoring wider ecosystem health. However, small carnivores are difficult to monitor using traditional methods. Although studies have used camera trapping to study the population status and habitat requirements of small carnivores, conventional camera trapping methods can result in limited detection rates for smaller-bodied carnivores. Consequently, there is a need to develop species- and guild-specific study designs for small carnivores. We tested the Mostela, a recently developed camera trapping method that has shown promising results for monitoring European small carnivore populations, across multiple land uses in the Garden Route, South Africa. To compare detection rates, we deployed 77 paired stations, consisting of a Mostela and a conventional camera trap, across seven surveys and six deployment locations. Using single-season occupancy models, we assessed the effects of method and baiting on detection probability. Mean daily detection probabilities were used to calculate the number of sampling days needed to reach 95% confidence in species' detection. Compared to conventional camera trapping, we found that the Mostela improved the naïve occupancy rates, capture frequency and detection probability for small carnivore species. The Mostela detected two small carnivore species (meerkat, Suricata suricatta; striped polecat, Ictonyx striatus) that were missed by conventional camera traps. On average, across species groups, seasons and treatments, a Mostela increased daily detection probability by 217%. Similarly, using bait, irrespective of method, increased daily detection probability by 184%. Cumulative detection probabilities indicated that the Mostela required fewer sampling occasions than conventional camera trapping to determine small carnivore presence at a site. Practical implication. We recommend the Mostela as an efficient sampling method for African small carnivore species. Future deployments across a range of habitats and community compositions would be beneficial to further explore the Mostela as a monitoring tool. Africa has a wide diversity and richness of small carnivore species for which there is a paucity of empirical data from which to make management and conservation decisions. As such, the Mostela could become an important tool for small carnivore monitoring strategies.