Shuanglong, a man of Mongolian ethnic group, installs an infrared camera near the mouth of a cave that the wolf may inhabit inside a valley along the Hulun Lake in the Hulun Buir City, north China's Inner Mongolia Autonomous Region, April 12, 2019. Shuanglong, a volunteer born in the 1980s, has been dedicated to protecting wildlife inhabiting along the Hulun Lake over the past ten years. Over 40 endangered animals have been saved through his efforts. Shuanglong has organized various activities including photo exhibitions and lectures, as a way to raise awareness of wildlife protection among the public. Affected by Shuanglong, some volunteers also joined him to protect wildlife along the Hulun Lake. (Xinhua/Peng Yuan)