Photo taken on Jan. 3, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)

Photo taken on Feb. 14, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)

Photo taken on Jan. 27, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)

Photo taken on Jan. 26, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)

Photo taken on April 21, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)

Photo taken on April 2, 2018 by an infrared camera shows a wild giant panda in Baishuijiang National Nature Reserve in northwest China's Gansu Province. (Xinhua/Baishuijiang National Nature Reserve)