Human Pressures Drive Global Mammalian Species Richness Loss and Community Change

Aim As the earth's human population increases, anthropogenic effects on ecosystems are also increasing. Mammalian communities are especially vulnerable, as more than one‐quarter of the world's mammal species are threatened with extinction. Therefore, it is important to determine how anthropogenic pressures have altered biodiversity. Location Global (approximately 79% of Earth's terrestrial area). Methods We used 1970s (“past”) and 21st century (“present”) range maps for 205 terrestrial non‐volant mammals to estimate change in species richness and community composition for 0.5° by 0.5° grid cells globally. We then used generalised linear models to examine how changes in climate and land use as well as elevation, the extent of protected areas, amount of wildlife trade, and environmental performance index affect mammal richness and community composition. Results We found that mammal communities experienced on average an exchange of about half their species, and mammal species richness has declined by a quarter of a species worldwide. Increased temperatures were linked to an increase in richness and greater community change. Areas with the greatest declines in richness and community change had fewer protected areas and increased agricultural land conversion. Main Conclusions While temperature change is the most important factor driving change in mammal community composition and richness, increased protected area and decreased conversion of land to agriculture led to increased preservation of richness and community composition. Our findings demonstrate the importance of understanding the impacts of climate change and maintaining natural and protected areas in biodiversity conservation.