Human pressures threaten diet-specialized mammal communities.

Abstract

Environmental change is increasing worldwide and many animal species face anthropogenic threats, especially diet specialists. Yet the degree to which specialist species are currently impacted by environmental change remains poorly understood. We examine how anthropogenic pressures impact dietary specialist species. We calculated indices of diet specialization for mammal species, based on the Gini inequality coefficient, and combined these indices with human pressure data. We then used spatially explicit Mantel tests to examine global patterns in mammal diet specialization. We used a generalized linear mixed model to investigate correlations between the percentage of diet specialist species in mammal communities in an area and its total species richness, human pressure and protection status (mediated through an interaction with the continent). Findings revealed that areas with many diet specialists in mammal communities are also impacted by high human pressure. Additionally, we found that the global protected area system adequately covers habitat for many mammal diet specialists, but has lower effectiveness in South America, Oceania, North America and Europe compared with Africa and Asia. Finally, we identified potential reservoirs for specialist species-places containing many highly diet specialist species and that are subject to less human pressure-which may be important for conservation efforts.