Photo taken on May 2, 2011 shows two birds fly in Ngari, southwest China's Tibet Autonomous Region. Since the foundation of the Qiangtang national nature reserve, Ngari has been a paradise for wild animals, among which more than 150,000 are protected at national level. Photo: Xinhua

Photo taken on May 2, 2011 shows running Tibetan antelopes in Ngari, southwest China's Tibet Autonomous Region. Since the foundation of the Qiangtang national nature reserve, Ngari has been a paradise for wild animals, among which more than 150,000 are protected at national level. Photo: Xinhua

Photo taken on May 2, 2011 shows running Tibetan antelopes in Ngari, southwest China's Tibet Autonomous Region. Since the foundation of the Qiangtang national nature reserve, Ngari has been a paradise for wild animals, among which more than 150,000 are protected at national level. Photo: Xinhua

Photo taken on May 2, 2011 shows the black-necked cranes in Ngari, southwest China's Tibet Autonomous Region. Since the foundation of the Qiangtang national nature reserve, Ngari has been a paradise for wild animals, among which more than 150,000 are protected at national level. Photo: Xinhua

Photo taken on May 3, 2011 shows running Tibetan antelopes in Ngari, southwest China's Tibet Autonomous Region. Since the foundation of the Qiangtang national nature reserve, Ngari has been a paradise for wild animals, among which more than 150,000 are protected at national level. Photo: Xinhua