This photo taken by mobile phone on Dec. 24, 2022 shows a flock of black-necked cranes in Lhunzhub County of Lhasa, capital of southwest China's Tibet Autonomous Region. Tibet has built 47 nature reserves covering a total area of about 412,200 square km. (Xinhua/Shen Hongbing)

This photo taken by mobile phone on Dec. 24, 2022 shows migratory birds in Lhunzhub County of Lhasa, capital of southwest China's Tibet Autonomous Region. Tibet has built 47 nature reserves covering a total area of about 412,200 square km. (Xinhua/Shen Hongbing)

This photo taken by mobile phone on Dec. 24, 2022 shows migratory birds in Lhunzhub County of Lhasa, capital of southwest China's Tibet Autonomous Region. Tibet has built 47 nature reserves covering a total area of about 412,200 square km. (Xinhua/Shen Hongbing)

This photo taken by mobile phone on Dec. 24, 2022 shows migratory birds in Lhunzhub County of Lhasa, capital of southwest China's Tibet Autonomous Region. Tibet has built 47 nature reserves covering a total area of about 412,200 square km. (Xinhua/Shen Hongbing)

This photo taken by mobile phone on Dec. 24, 2022 shows migratory birds in Lhunzhub County of Lhasa, capital of southwest China's Tibet Autonomous Region. Tibet has built 47 nature reserves covering a total area of about 412,200 square km. (Xinhua/Shen Hongbing)