Abstract: During overwintering of the years 2018－2023, a total of 59 species of waterbirds belonging to 12 families and 7 orders, including 5 species of first-level nationally protected waterbirds and 9 species of second-level nationally protected waterbirds, were recorded. The results showed that there were significant differences in the diversity indexes of waterbird communities among different foraging guilds, and the change range of diversity index for different types was Shannon-Wiener Diversity Index > Margalef Richness Index > Simpson Dominance Index > Pielou Evenness Index. The response of waterbird populations in different foraging guilds was different to water level changes. Among them, there was a significant negative correlation between the populations of fish-eating group, sedge-eating group and invertebrate-eating group and water level. Water level changes had significant impact on the area of three habitats: water body, grassland and mudflat. In the future, water level regulation should be optimized to maintain abundant food resources for overwintering waterbirds, which is of great significance for improving the diversity of waterbird communities in Caizi Lake.

Key words: Caizi Lake, overwintering, waterbirds, foraging guild, water level change