Between the broad-leaf evergreens of northern Vietnam's Khau Ca Forest, a pair of blue-ringed eyes peer across the limestone canopy—a sighting that once seemed impossible. The Tonkin snub-nosed monkey, presumed extinct by the 1980s after centuries of hunting for traditional medicine and bushmeat, is making an unexpected comeback in this remote corner of the world.
The story of this species is one of ecological near-death and surprising resurrection. Endemic to Vietnam and found nowhere else on Earth, the Tonkin snub-nosed monkeys were hunted so relentlessly and sightings became so rare that conservationists had written them off. Then, in the late 1980s and 1990s, a handful of fragmented populations were rediscovered—tiny, scattered groups clinging to survival in isolated forest patches. But in 2002, when a population of just 50 monkeys was found in Khau Ca Forest Reserve, it marked the beginning of a conservation story that would defy the odds.
Today, that population has more than tripled. A comprehensive census conducted in October and November 2025 counted 160 Tonkin snub-nosed monkeys living in Khau Ca—an estimated 80 percent of the entire remaining species. "It's one of our most successful surveys," says Canh Xuan Chu, project manager for the Tonkin snub-nosed monkey program at Fauna & Flora International, the conservation nonprofit that has anchored the recovery effort since 2002.
The turnaround rests on a simple but effective strategy: protecting both the forest and the people who live alongside it. When Fauna & Flora established a conservation field station in Khau Ca, they didn't just focus on the monkeys. Instead, they organized community conservation teams to patrol the 1,000-hectare reserve, removing snares and reporting signs of illegal hunting or deforestation. To support villagers whose livelihoods once depended on foraging and farming in the forest, the project created new income streams through conservation work itself, ensuring that protecting the monkeys benefited the communities sharing the land.
Conservation partners like the New Nature Foundation and Denver Zoo extended this philosophy, distributing fuel-efficient stoves that cut firewood consumption by half—reducing pressure on the forest without impoverishing households. The result has been measurable. Tran Van On, a member of Fauna & Flora's community conservation team, reports a "significant increase" in community awareness around the species. "People are now not only more conscious about protecting this endemic species of Vietnam, but also more aware of the importance of safeguarding forest habitats and other wildlife species," he said.
The most recent survey, the most comprehensive to date, deployed cutting-edge technology alongside traditional methods. More than 30 people from the conservation unit and local communities divided into ten teams, each responsible for a mapped section of the reserve. They spent ten days camping in the forest, using thermal imaging drones, camera traps, and specialized acoustic sensors called audiomoths to detect the monkeys' unique calls. For Chu, who has worked on the project for seven years, spotting individual monkeys has become second nature: "They're so different: you see the coloring, you see the tail; and the other thing is, their calls to each other are different, so it's very clear."
The contrast with other locations is stark. Quan Ba, once home to the second-largest population, tells a grimmer tale. But Khau Ca stands as proof that critically endangered species can recover when communities and conservation work hand in hand, offering a blueprint for restoring populations across Vietnam's forests.