Over the past 30 years, the number of bird species in the Yellow River Delta National Nature Reserve in Dongying, Shandong province, has doubled, increasing from 187 to the current 373 species.

Researchers discovered rare bird species such as the Mute Swan and the Black-faced Spoonbill living and breeding in the reserve this year.

The migratory bird habitat at the Yellow River estuary in Dongying as part of the Migratory Bird Sanctuaries along the Coast of the Yellow Sea-Bohai Gulf of China (Phase II), was listed as a World Natural Heritage site in July during the 46th session of UNESCO's World Heritage Committee in New Delhi.

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.

World Heritage refers to the rare and irreplaceable wealth confirmed by the UNESCO World Heritage Committee, recognized by all humanity as having outstanding significance and universal value, including cultural relics and natural landscapes.

China's Migratory Bird Sanctuaries along the Coast of the Yellow Sea-Bohai Gulf are being nominated for World Natural Heritage in two phases. The first phase, nominated by Yancheng, Jiangsu province, was approved and listed in the World Heritage List during the 43rd World Heritage Conference in 2019.

The second phase is an extension of the first, including an estuarine wetland in Chongming, Shanghai; a wetland area in Cangzhou, Hebei province; a national-level nature reserve in Dalian, Liaoning province; the Yalu River estuary in Dandong, Liaoning; and also the Yellow River estuary in Dongying, Shandong.