Waterbird Diversity Patterns Under Varied Hydrological Regimes in Dongting Lake and Surrounding Lakes.

Globally, climate and human-induced environmental changes affect the populations and distributions of most organisms. This is particularly true for migratory birds, which change habitats throughout the annual cycle. Understanding how waterbirds adapt to environmental change is important for their conservation; however, this subject remains largely unexplored. Based on wintering waterbirds and environmental data from Dongting Lake and its surrounding lakes, we compared the changes in waterbird diversity in subregions with different habitat variations during four hydrological periods. This allowed us to identify key environmental factors affecting waterbird diversity and explore the potential mechanisms by which waterbirds adjust to these environmental changes using the waterbird-habitat patch network method. The results indicated that waterbird distribution differed across Dongting Lake and the surrounding wetlands under varying hydrological conditions associated with habitat changes. Notably, the surrounding lakes with stable habitats served as refuges for waterbirds during extreme drought, with the percentage of waterbirds increasing from 9.3% (late recession) to 63.8% (extreme drought). Areas of habitat (i.e., water, mudflat, and vegetation) and human disturbance were key factors influencing waterbird diversity. As indicated by the