Regional differences in wintering habitat selection strategies of Siberian Crane (Leucogeranus leucogeranus) and ecological network construction of key wintering areas

Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the MaxEnt model to assess wintering habitat suitability in Poyang Lake (PYL) and the Yellow River Delta (YRD). Landscape pattern and ecological network (EN) analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover (LULC) change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km². In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km². Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL’s EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.