Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)
Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)
Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)
Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)
Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)
Swans are seen at the Yellow River Wetland in Pinglu County, north China's Shanxi Province, Jan. 4, 2018. (Xinhua/Zhan Yan)