Stage-Specific Impacts of Climate Change on Greater White-Fronted Geese Along the East Asian Flyway

Migratory flyways sustain waterbird populations by linking critical habitats across their annual cycle. However, stage-specific impacts of climate change on these habitats remain poorly understood. We integrated species distribution models with annual migration data from 30 Greater White-fronted Geese (<i>Anser albifrons frontalis</i>) to assess changes in habitat suitability, distributional shifts, and suitability fluctuations across breeding, stopover, and wintering stages under mid-century (2040-2060) climate scenarios. Suitability fluctuations were quantified as the coefficient of variation (CV) in habitat suitability between current and future projections. Projected habitat responses varied markedly across stages: breeding areas contracted by 29.9%, wintering areas expanded by 62.7%, and stopover sites showed minimal net change. Centroids of all habitats are projected to shift northward by mean distances of 125-492 km under future climate scenarios. Breeding habitats exhibited the greatest suitability fluctuations (CV=30-45; ~50% area affected under SSP585), followed by stopover and wintering grounds (CV ≈ 11), with 35.8% and 23.3% of their areas falling within high-fluctuation zones. These findings highlight the urgent need to prioritize breeding habitats, implement stage-specific conservation strategies, and enhance international cooperation to ensure the protection of waterbirds along the East Asian Flyway.