Assessing Habitat Suitability and Climate-Change Responses of Raptors in Hunan Province, China, Using Ensemble Species Distribution Models

Raptors are high-trophic-level predators and scavengers that are sensitive to habitat alteration, human disturbance, and climate variability, yet province-wide assessments of their habitat suitability and climate-change responses remain limited in subtropical China. Hunan Province, located along the inland section of the East Asian–Australasian Flyway, contains complex mountain systems, plains, wetlands, and land-use mosaics that may support diverse raptor assemblages. Based on raptor survey records collected across Hunan from January 2022 to July 2023, we used biomod2 ensemble species distribution models to assess current habitat suitability, identify key environmental predictors, and project future changes under the SSP2-4.5 and SSP5-8.5 scenarios for the 2050s and 2090s. We recorded 39 raptor species and retained 3637 valid geographic locations and 4855 observed individuals after data cleaning. Nine representative species were further selected to construct 22 species–season combinations covering resident species, summer visitors, winter visitors, and four phenological stages. The EMwmean weighted ensemble model consistently outperformed the best single models, increasing mean AUC from 0.882 to 0.970 and the mean TSS from 0.611 to 0.845. Temperature seasonality (BIO4), the Human Footprint Index (HFP), precipitation in the driest month (BIO14), and the Normalized Difference Vegetation Index (NDVI) were the dominant predictors, although their relative importance varied among residency types and phenological stages. Under current conditions, highly suitable and most suitable habitats covered 65,259.67 km2, accounting for 30.81% of Hunan Province, and were mainly concentrated in western, southern, and eastern mountain regions. Future projections indicated a marked contraction of high-suitability habitats, especially under SSP5-8.5, with no HSI > 0.6 habitat identified by the 2090s. High-suitability habitats also became increasingly concentrated at higher elevations. These findings identify mountain regions as key conservation priorities and provide a spatial framework for climate-adaptive raptor conservation in Hunan Province.