Whooper swans fly at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
Whooper swans play at the wetland of Yellow River in Pinglu County, north China's Shanxi Province, Nov. 2, 2017. Many whooper swans came to spend the winter time in the wetland every year. (Xinhua/Xue Jun)
