Assessing global patterns in mammalian carnivore occupancy and richness by integrating local camera trap surveys


Aim: Biodiversity loss is a major driver of ecosystem change, yet the ecological data required to detect and mitigate losses are often lacking. Recently, camera trap surveys have been suggested as a method for sampling local wildlife communities, because these observations can be collated into a global monitoring network. To demonstrate the potential of camera traps for global monitoring, we assembled data from multiple local camera trap surveys to evaluate the interchange between fine- and broad-scale processes impacting mammalian carnivore communities. Location: Argentina, Belize, Botswana, Canada, Indonesia, Iran, Madagascar, Nepal, Norway, Senegal, South Africa, and the U.S.A. Methods: We gathered camera trap data, totalling >100,000 trap nights, from across five continents. To analyse local and species-specific responses to anthropogenic and environmental variables, we fitted multispecies occurrence models to each study area. To analyse global-level responses, we then fitted a multispecies, multi-area occurrence model. Results: We recorded 4,805 detections of 96 mammalian carnivore species photographed across 1,714 camera stations located in 12 countries. At the global level, our models revealed that carnivore richness and occupancy within study areas was positively associated with prey availability. Occupancy within study areas also tended to increase with greater protection and greater distances to roads. The strength of these relationships, however, differed among countries. Main conclusions: We developed a research framework for leveraging global camera trap data to evaluate patterns of mammalian carnivore occurrence and richness across multiple spatial scales. Our research highlights the importance of intact prey populations and protected areas in conserving carnivore communities. Our research also highlights the potential of camera traps for monitoring wildlife communities and provides a case study for how this can be achieved on a global scale. We encourage greater integration and standardization among camera trap studies worldwide, which would help inform effective conservation planning for wildlife populations both locally and globally.



big data analysis, camera trap, carnivore, global, hierarchical Bayesian models, multispecies modelling, species occurrence, species richness