A herd of kiangs (Equus kiang) gallop in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 1, 2018. (Xinhua/Jiang Wenyao)

A wolf gallops in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)

Two vultures are seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)

A Tibetan antelop is seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 1, 2018. (Xinhua/Jiang Wenyao)

This aerial photo taken on April 2, 2018 shows a wild yak in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region. (Xinhua/Jiang Wenyao)

A galloping kiang (Equus kiang) is seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 1, 2018. (Xinhua/Jiang Wenyao)

A preying wolf is seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)

This aerial photo taken on April 3, 2018 shows a herd of kiangs (Equus kiang) in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region. (Xinhua/Jiang Wenyao)

A Tibetan antelope is seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 1, 2018. (Xinhua/Jiang Wenyao)

A wild yak makes its way across a desert in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)

Three wild yaks are seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)

A wild yak is seen in the Altun Mountains National Nature Reserve in northwest China's Xinjiang Uygur Autonomous Region, April 2, 2018. (Xinhua/Jiang Wenyao)