Updated Global Population Estimates of Three Endemic Crane Species in Northeast Asia: Wintering Status and Conservation Implications in Korea and Japan

Red-crowned (Grus japonensis, RCC), White-naped (G. vipio, WNC), and Hooded Cranes (G. monacha, HC) are threatened endemic species in Northeast Asia. Their continental populations comprise two subpopulations: an eastern subpopulation that winters in Korea and Japan and a western subpopulation wintering in China. Population figures cited from the IUCN Red List are outdated (assessed: RCC 2021; WNC 2018; HC 2016). Accordingly, this review synthesized official winter censuses from Korea and Japan (1998–2023), harmonized across countries, to assess wintering trends and site status of the eastern subpopulation. Recent Chinese literature was reviewed to update global crane population estimates. The updated global population sizes of RCC, WNC, and HC were estimated at approximately 4600, 13,100, and 19,300 individuals, respectively. The eastern subpopulations are increasing in proportion and comprise approximately 44.5%, 97.1%, and 96.2%, respectively, of the totals. However, accuracy of global population estimates was limited by heterogeneity in census protocols between Korea and Japan and by temporal lags between Chinese literature-based and Korea–Japan census data. Standardized survey protocols and transboundary data sharing are needed to obtain more accurate estimates of these populations. The standardized datasets provide baseline data for establishing wintering-site management strategies to ensure sustainable conservation of these species.