The number of wild gray snub-nosed monkeys, an endangered species only found in southwest China's Guizhou Province, has more than doubled to about 850 over the past three decades.

The monkey, the rarest among the three species of golden monkeys in China's Sichuan, Yunnan, Gansu and Hubei provinces, mainly lives in the 419-square-kilometer mountainous Fanjingshan National Nature Reserve in Guizhou.

Thanks to the steady improvement of the environment and government protection measures. the number of the animals has risen to about 850 compared with 400 in 1979, according to the Fanjingshan National Nature Reserve Administration Bureau.

The monkey's reproductive cycle is three to six years. It is on the list of China's most endangered wild animals.

Since 1992, the bureau has successfully bred 16 such monkeys from seven captured from the wild.