Four Yunnan snub-nosed monkeys, also known as black-and-white snub-nosed monkeys, have been born in a nature reserve in southwest China's Yunnan Province since January 25, the reserve administration said Monday.

The newborns have brought the total number of 15 monkey groups in the Baima Snow Mountain Nature Reserve, a major habitat for the species in China, to about 2,800, or 75 percent of the world's total.

"To ensure a natural state, the rangers won't interfere with the growth of the monkeys, only putting pine cones, dried apples, pumpkin seeds and other supplementary foods based on the situation, to help improve the animals' health," said Lai Jiandong, a ranger of the reserve.

As one of the world's most endangered primates and listed on the International Union for Conservation of Nature Red List of threatened species, the monkey is considered a bellwether species for biodiversity in the high-altitude region, living in the mountainous forests in Yunnan and its neighboring Tibet Autonomous Region.

Local poachers drove them close to extinction in the 1980s, but their number has since risen above 3,500 nationally thanks to the joint efforts of government, researchers and local villagers.