Introduction to migratory birds in Yueqing: Yueqing Bay is rich in wetland resources and has many waterfowl. There are many national second-level protected birds and critically endangered birds such as herons, great egrets, red-necked ducks, and black-billed gulls. Among them, there are only more than 5,000 black-billed gulls in the world, and 3,160 were found in Yueqing Bay.