A flock of tundra swans rest in the Liaohekou National Nature Reserve, northeast China's Liaoning Province, March 19, 2017. The reserve is the rest place where the birds migrate to the north. (Xinhua/Pan Yulong)
A flock of tundra swans rest in the Liaohekou National Nature Reserve, northeast China's Liaoning Province, March 19, 2017. The reserve is the rest place where the birds migrate to the north. (Xinhua/Pan Yulong)