Flocks of whooper swans have gathered at a warm-water river of the Ruoergai Grassland in southwest China's Sichuan Province.

The river, known as Luojiaqiongguo, has geothermal heat, and its water does not freeze all the year round. It attracts thousands of whooper swans from November to March every year. The birds come from northeast China and Russia's Siberia for wintering.

The whooper swan is under second-class state protection in China. It's one of the highest flying birds in the world, capable of flying over the roof of the world, the Qomolangma. Its highest flying height hits more than 9,000 meters.

Ruoergai Grassland enjoys the reputation of "the most beautiful high-altitude wetland grassland in China" and is also an important wintering and resting place for migratory birds.

According to incomplete statistics, there are 162 species of birds in Ruoergai County, accounting for 26 percent of the bird species in Sichuan Province, and 12.2 percent in China.

(Cover image via VCG, video provided by CGTN's Meng Qingsheng.)

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