Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans takes off from a lake on the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015. Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
Wild whooper swans are seen at the Yellow River Wetland in Pinglu, north China's Shanxi Province, Nov. 4, 2015.Thanks to its better ecological environment, the wetland attracted more whooper swans to spend winter in recent years. (Xinhua/Zhan Yan)
