The population of endangered Yunnan snub-nosed monkeys in the Yunlong Tianchi National Nature Reserve in southwest China has risen to about 350, a recent ecological survey shows. The increase reflects healthier habitats and steady conservation gains.

Researchers observed active, healthy groups during monitoring, even tracking their mountain-crossing routes and behaviours. Yunlong Tianchi lies at the southernmost edge of the species’ range and is the only national reserve in China where this first-class protected primate lives so far south.

When the monkeys were first recorded in Longma Mountain in 1988, only 50 to 60 of them were found. Since then, the reserve has restored ecological corridors linking its northern and southern sections, planting spruce, Armand pine and fir to support movement and genetic exchange.

A joint survey in November confirmed the population has grown by about 300 since monitoring began. Li Yunfang, deputy head of research of the reserve, said the monkeys “have grown steadily … and [their] habitat has been markedly improved.”