Predicting <italic>Eremias argus</italic> Habitat Changes under Climate Change in the Republic of Korea

Background and objective: Climate change is accelerating biodiversity loss, and reptiles, being ectothermic and highly dependent on external conditions, are especially vulnerable. <i>Eremias argus</i>, an endangered species in South Korea, prefers dry, open habitats, but its range has been increasingly fragmented by urbanization and agriculture. Yet, quantitative projections of habitat changes for this species under climate scenarios remain scarce in Northeast Asia. This study aimed to evaluate current and future habitat suitability of <i>Eremias argus</i> in South Korea under different climate pathways.Methods: Occurrence records from the National Institute of Ecology (2007–2018) were combined with climate, topographic, land-cover, and distance variables. Pseudo-absence points, 3 times the number of presences, were generated to reduce data imbalance. 14 predictors were retained after multicollinearity testing. 8 algorithms were run in the BIOMOD2 framework, and an ensemble model (weighted mean) was built using AUC scores. Suitability was projected under baseline climate (2007–2018) and two future scenarios, Shared Socioeconomic Pathway (SSP)2–4.5 and Shared Socioeconomic Pathway (SSP)5–8.5, for mid-century (2041–2070) and late-century (2071–2100).Results: The ensemble model performed strongly (AUC = 0.978), with single models ranging from 0.51 to 0.89. Current suitable areas are concentrated in the mountainous regions of Gangwon and northern Gyeongbuk. Under SSP2–4.5, habitat extent is projected to decline by 47.2% by mid-century and 43.2% by late-century. Under SSP5–8.5, losses are greater, with a 60.7% reduction by mid-century and only 45.3% of current habitat persisting by late-century. Key predictors included distance to natural areas, topographic wetness index, distance to Ocean, and precipitation seasonality.Conclusion: More than half of the suitable habitat for <i>Eremias argus</i> may vanish under climate change, but inland mountainous areas remain relatively stable. These zones should be prioritized for conservation, providing evidence to guide biodiversity protection and climate-adaptation planning in Northeast Asia.