A heron flies at the West Dongting Lake in Changde, central China's Hunan Province, Nov. 11, 2020. The West Dongting Lake, along with its biologically rich wetlands, has been a thoroughfare for migratory birds. About 20,000 migratory birds have arrived at West Dongting Lake so far this year. (Xinhua/Chen Sihan)

A flock of migratory birds fly over the West Dongting Lake in Changde, central China's Hunan Province, Nov. 11, 2020. The West Dongting Lake, along with its biologically rich wetlands, has been a thoroughfare for migratory birds. About 20,000 migratory birds have arrived at West Dongting Lake so far this year. (Xinhua/Chen Sihan)

A heron rests at the West Dongting Lake in Changde, central China's Hunan Province, Nov. 11, 2020. The West Dongting Lake, along with its biologically rich wetlands, has been a thoroughfare for migratory birds. About 20,000 migratory birds have arrived at West Dongting Lake so far this year. (Xinhua/Chen Sihan)

A heron walks at the West Dongting Lake in Changde, central China's Hunan Province, Nov. 11, 2020. The West Dongting Lake, along with its biologically rich wetlands, has been a thoroughfare for migratory birds. About 20,000 migratory birds have arrived at West Dongting Lake so far this year. (Xinhua/Chen Sihan)