LANZHOU, March 24 (Xinhua) -- Big hordes of wild camels have been frequently spotted by infrared cameras set in the Dunhuang West Lake National Nature Reserve near the Mogao Grottoes, a renowned UNESCO World Heritage Site in northwest China's Gansu Province.

The reserve administration said the cameras set at two locations in the reserve captured wild camels with a big horde of up to 35 specimens, indicating the population of the wild species is expanding.

The reserve built in 1992 was upgraded into a national nature reserve in 2003. It aims to prevent the Kumtag Desert from moving eastward and help maintain the local biodiversity, as desertification poses a constant threat to the cultural heritage in Dunhuang. The lake reserve is also the major habitat for wild camels in China.

"Three years ago, we monitored a horde with 10 wild camels as a large group, which only appeared once every few years. Now, cameras often catch large groups each with more than 30 camels," said Sun Zhicheng, chief engineer of the reserve administration.

He attributed the recovery to the administration's efforts to keep reducing human interference and carry out water conservation in the Shule River.

In addition to camels, the cameras also captured images of desert cats and other wild animals such as golden eagles, antelope, lynx, sand foxes.

The reserve with a large area of wetland and desert vegetation is considered as an ecological barrier in the juncture of Jiuquan and Dunhuang in Gansu and the Lop Nur in Xinjiang Uygur Autonomous Region in the west.