Infrared cameras capture images of a wild giant panda in nature reserves in China. [Photo provided to China Daily]

Since 2008, reserve rangers have worked with the WWF and set up about 40 infrared cameras in the woods to take photos automatically when a living creature passes by.

In 2010, one of the infrared cameras captured the first image of a wild panda in Liangshan prefecture. The last time that the nature reserve snapped an image of the black-and-white animal was last May, when it was marking its territory.

"Our aim is to protect wild giant pandas in a scientific way. Such new technology and ideas are important," WWF's Xu says.

"It's more objective to measure work achievement via surveillance cameras. It's good for data saving, too－otherwise, you will have to input into a computer the data that are originally recorded on piles of paper," Xu says.