A Tibetan brown bear at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

Wild donkeys at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

Wolves at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

A guanaco yawns at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

Sika deer at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

Porcupines at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

A manul at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

Ring-tailed lemurs at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)

A bharal at the Qinghai-Tibet Plateau Wildlife Zoo in Xining City, Qinghai Province, March 14, as temperatures gradually rise. (Photo: China News Service/Luo Yunpeng)