Scenario-dependent northward shifts in wintering centroids of Anatidae in South Korea.

Climate and land-use change are reshaping the spatial ecology of migratory waterbirds, yet few studies in East Asia have quantitatively integrated ensemble species distribution models, land-cover dynamics, and multi-scenario climate projections to assess future shifts and fragmentation of wintering habitats. We quantified climate-driven changes in the wintering distributions of six rice-paddy-dependent Anatidae species across South Korea using an ensemble species distribution modelling framework integrating nine algorithms. Species occurrence data from GBIF and field surveys (2022-2024) were combined with land-cover, topographic, and bioclimatic variables, with future projections generated under four Shared Socioeconomic Pathways (SSP126, SSP245, SSP370, SSP585) and four time periods (2021-2040, 2041-2060, 2061-2080, 2081-2100). Across all scenarios, wintering distributions exhibited pronounced northward shifts, reduced spatial overlap with historical hotspots, and increasing habitat fragmentation. The loss of southern wintering grounds-historically critical as climatic refugia during extreme cold events-combined with the rapid expansion of greenhouse-based agriculture threatens the stability of emerging northern habitats. While northward shifts may facilitate adaptation to gradual warming, they also heighten vulnerability to short-term climatic extremes, forcing energetically costly movements to suboptimal sites. These findings underscore the urgency of climate-informed conservation planning.