The Yellow River estuary is a crucial stopover, wintering and breeding site for migratory birds in the East Asian-Australasian Flyway, earning the nickname of "international airport for birds" from global experts. It is home to 26 species of birds under national first-class protection and 65 species under national second-class protection.
The East Asian-Australasian Flyway extends from the Arctic through Southeast Asia to Oceania, spanning 22 countries.
Li Xingjie, a researcher of the Yellow River Delta National Nature Reserve, said that the Yellow River estuary possesses the most intact wetland ecosystem in China's warm temperate zone.