Recent breeding by Red-crowned Cranes in the Yellow River Delta: multiscale wetland associations
Year: 2026
Type: preprint
Abstract: The Yellow River Delta has long been recognized as a stopover and wintering site for the vulnerable Red-crowned Crane (Grus japonensis), but breeding records since 2019 indicate that this coastal wetland is also being used during the breeding season. We combined field-confirmed active nests (n = 12) with 60 reserve-wide background points, multiscale Sentinel-2 indices, and annual China Land Cover Dataset (CLCD) products from 2017 to 2023 to identify environmental conditions associated with recent nesting. At 100 m, active nests had higher NDMI and a greater proportion of NDMI-positive pixels, together with lower BSI and fewer pixels with BSI > 0.1. At broader scales, nests were associated with higher proportions of water-, grassland-, and wetland-class cover and lower cropland and impervious cover, while annual trajectories showed that active nest sites occurred within a changing land-cover mosaic. These results indicate that recent nesting is associated with the convergence of moisture-related near-nest conditions and heterogeneous wetland surroundings rather than with a single habitat component. Together with earlier breeding records, the 2024 nests show that breeding-season use has emerged at a site historically used mainly during migration and winter. Whether this use persists and contributes to recruitment will require multi-year monitoring of nest fate, fledging success, and juvenile recruitment.
Institution: Beijing Forestry University
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W7204496356