NANCHANG, June 1 (Xinhua) -- Rare muntjacs have been spotted in a nature reserve in east China's Jiangxi Province.

The black muntjacs, under Class One national protection in China, were caught on infrared cameras recently in the Jiangxi Wuyi Mountain National Nature Reserve. In 2011, the muntjacs were spotted in the reserve for the first time.

The animals were discovered in the 19th century, and have been found in a dozen mountainous counties in China. But the development of human society has threatened the survival of the animals, causing their number to decrease. Currently, there is estimated to be fewer than 10,000 muntjacs in China.

"The black muntjacs are usually active in the morning and at dusk, and they love to eat herb leaves and twigs," said Cheng Lin, a senior engineer at the reserve. "The appearance of the animals shows that the environment here in the reserve is quite good."

Pictures and video footage of the muntjacs indicate that a stable number of muntjacs live in the reserve, Cheng said.

"The reserve will enhance supervision and protection of the muntjacs, while also stepping up research on them," Cheng said.