Dongtan, Chongming Island, is currently the largest bird habitat in the Shanghai area and an important stop on the internationally renowned Asia Pacific migration route. Investigations from autumn 1997 to spring 2001 within Dongtan (including both the interior and exterior of the reclamation area) recorded 181 species, 13 orders, and 26 families of birds. Among them are two species under Grade 1 National Protection: Ciconia ciconia and Grus monacha; nine species of birds in Grade 2, including Platalea leucorodia and Platalea minor; and 5 species of birds that are listed as being in danger under international trading treaties for the protection of wild animals. 72 species are listed under the China-Japan Bird Protection Agreement, and 37 species are listed under the China-Australia Bird Protection Agreement. Of the 181 species under recent observation, 97 are typical wetland birds.

From the last 10 days of March until the first 10 days of May, migrating birds on the Asia-Pacific migration route pass through Dongtan, Chongming Island on their way from their winter habitat in Australia to their nesting grounds in Siberia, and then return around the middle of September until the first 10 days of November when they migrate back to Australia. Generally, the flocks migrating south are small, extending their migration time, and they stay on Dongtan for a somewhat long time (5~7 days). During spring, the flocks migrating north are consistently large and travel quickly. They remain on Dongtan for a short time (3~5 days). Both of these two periods constitute peak aggregations of birds on Dongtan, but the quantity and variety of species are usually greater in spring than in autumn.