Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen crossing a road at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)

　　Blue sheep are seen at the base camp area of Mount Everest with an altitude of 5,200 meters in southwest China's Tibet Autonomous Region, July 27, 2015. The total number of blue sheep here has increased by 40 percent in the past 27 years due to the enhanced wildlife conservation. (Xinhua/Zhang Rufeng)