XINING -- A mating snow leopard couple had been photographed in northwest China's Qinghai Province, snow leopard conservation researchers said Sunday.

Infrared cameras in a leopard habitat in Zadoi County in Yushu Tibetan Autonomous Prefecture recorded the mating process on Jan. 29. The cameras, installed in late 2015, were retrieved in early April, said Zhao Xiang, who works with the non-governmental Shanshui Conservation Center (SCC).

Judging from publicly available documents, it was the first time that the mating of snow leopards were photographed, Zhao said.

In five months, infrared cameras installed in an area of 300 square kilometers took 126 photos of 13 leopards, Zhao said.

The cameras were installed by local herders who were trained by the SCC and local government in a volunteer project to protect snow leopards, said Shi Xiangying, another staff with the SCC.

Local herders also helped the SCC check the infrared cameras to keep them functioning. A volunteer managed two cameras, with each sitting at the center of a 25-square-km square.

Snow leopards are usually found in the Qinghai-Tibet Plateau and Pamir Plateau at altitudes over 3,500 meters, with a number of less than 5,000 worldwide, including about 2,000 in China.

Snow leopards have been spotted often in recent years in northwest China due to local ecological protection efforts.