Photo taken on July 14, 2016 shows a blue sheep in Helan Mountain of northwest China's Ningxia Hui Autonomous Region. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Photo taken on July 14, 2016 shows a blue sheep in Helan Mountain of northwest China's Ningxia Hui Autonomous Region. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A blue sheep stands near a cliff in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A blue sheep walks on rocks in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Photo taken on July 14, 2016 shows a blue sheep in Helan Mountain of northwest China's Ningxia Hui Autonomous Region. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Blue sheep search for food in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A blue sheep runs across a winding mountain highway in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A baby blue sheep and its mother stand near a cliff in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A blue sheep stands near a cliff in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Blue sheep rest on rocks in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

A blue sheep walks on rocks in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Blue sheep search for food in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz

Blue sheep search for food in Helan Mountain of northwest China's Ningxia Hui Autonomous Region, July 14, 2016. Blue sheep is a nationally protected species and a kind of endangered wildlife in China. Currently there are about 14 to 17 blue sheep per square kilometer in Helan Mountain. (Xinhua/Peng Zhaoz