Aerial photo taken on Dec. 11, 2020 shows a view of the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province.Photo:Xinhua

Two water birds are seen at the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Dec. 11, 2020.Photo:Xinhua

Two ruddy shelducks hover over the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Dec. 11, 2020.Photo:Xinhua

A flock of ruddy shelducks hover over the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Dec. 11, 2020.Photo:Xinhua

Aerial photo taken on Dec. 11, 2020 shows a view of the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province.Photo:Xinhua

Two egrets frolic at the Qianzi Lake wetland park in Guide County, Hainan Tibetan Autonomous Prefecture, northwest China's Qinghai Province, Dec. 11, 2020.Photo:Xinhua