Photo taken on February 4 shows blue sheep at the Mount Qomolangma National Nature Reserve. With a variety of ecosystems and rich biological resources, Mount Qomolangma National Nature Reserve is a paradise for wildlife. [Photo/Xinhua]

Photo taken on February 3 shows black-necked cranes at the Mount Qomolangma National Nature Reserve. With a variety of ecosystems and rich biological resources, Mount Qomolangma National Nature Reserve is a paradise for wildlife. [Photo/Xinhua]

Photo taken on February 5 shows a running wild wolf at the Mount Qomolangma National Nature Reserve. With a variety of ecosystems and rich biological resources, Mount Qomolangma National Nature Reserve is a paradise for wildlife. [Photo/Xinhua]

Photo taken on February 5 shows Tibetan wild donkeys at the Mount Qomolangma National Nature Reserve. With a variety of ecosystems and rich biological resources, Mount Qomolangma National Nature Reserve is a paradise for wildlife. [Photo/Xinhua]

Photo taken on February 5 shows black-necked cranes at the Mount Qomolangma National Nature Reserve. With a variety of ecosystems and rich biological resources, Mount Qomolangma National Nature Reserve is a paradise for wildlife. [Photo/Xinhua]