An increasing number of migratory birds, including some species on the endangered list, are overwintering at the Chongming Dongtan Nature Reserve, an important avian habitat on an island in the Yangtze River estuary.

Located to the north of Shanghai, Chongming is China's third-largest island, after Taiwan and Hainan. Overdevelopment of the river in recent decades has had a disastrous effect on the local ecosystem, so Chongming has made ecology a priority. It is aided by the municipal government, which is actively promoting environmental protection, energy conservation and sustainable development.

As of mid-January, 28,264 birds from 43 species had been tracked arriving at the 242-square-kilometer reserve on the eastern end of the island, treating it either as a brief stopover during migration or as a winter base, according to official data.