WUHAN - The population of golden monkeys in central China's Shennongjia National Nature Reserve, Hubei province, has risen to more than 1,300, double that of in 1990, sources with the reserve said Wednesday.

The reserve began a census on the endangered species in August 2015.

"In addition to the increase of population, the animals have begun to range outside the reserve to neighboring areas such as Badong and Xingshan," said Yang Jingyuan, director of the reserve's research institute.

The first golden monkey census in Shennongjia showed that there were 501 of the species in the reserve in 1990, Yang said.

The golden monkeys in Shennongjia are golden snub-nosed monkey, one of the five golden monkey species. They mainly live across the southwest province of Sichuan, the northwestern provinces of Shaanxi and Gansu, and central China's Shennongjia. Golden monkeys are highly endangered and under first class protection.

Located in the northwestern mountains in Hubei, Shennongjia reserve has rich natural forest resources and many animal species. Shennongjia was recognized as a World Natural Heritage site at the 40th session of the World Heritage Committee held in Istanbul,Turkey, in July.