Identifying conservation priorities in global Biodiversity Hotspots to protect small-ranged vertebrates from agricultural pressure

Biodiversity Hotspots (Hotspots), harboring exceptionally rich small-ranged species, are critical for mitigating biodiversity loss. As priorities for terrestrial conservation, Hotspots increasingly face threats from agriculture, the largest anthropogenic disturbance impacting biodiversity. Yet, the spatial dynamics of agricultural expansion and its impacts on biodiversity, especially small-ranged vertebrates, remain poorly understood. Using site-level observations and satellite imagery, we found that agricultural pressures reduce species richness by 25.8%, total abundance by 12.4%, and rarefied species richness by 8.7% relative to primary vegetation within Hotspots. However, cropland area within Hotspots expanded 12% from 2000–2019, exceeding the global average of 9%. Fine-scale analysis identified 3,483 risk spots (cropland expansion and high small-ranged vertebrate richness, ~1741 Mha); ~1031 Mha of these areas fall outside Protected Areas, particularly in the Atlantic Forest, Indo-Burma, Western Ghats, Sri Lanka, and Sundaland. These results underscore the urgent need for targeted conservation actions to prevent biodiversity loss from agricultural expansion. Croplands in biodiversity hotspots expand rapidly from 2000 to 2019 at a rate above the global average, and more than half of conservation gaps are found within the hotspots, as revealed by site-level observations and satellite data.