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Between the branches of broad-leaf evergreens, a pair of blue-ringed eyes stare throughout the treetops of Khau Ca’s limestone forest.
It’s a uncommon glimpse of one of many world’s most endangered monkeys — and one which subject conservationist Canh Xuan Chu relishes.
Tonkin snub-nosed monkeys are endemic to Vietnam, and solely discovered in fragmented patches of forest in two of the nation’s northernmost provinces, bordering China.
A inhabitants of simply 50 was found in Khau Ca in 2002, including to the handful of areas the place the species was rediscovered in the late Eighties and Nineteen Nineties, after being presumed extinct.
Today, the monkeys have all however disappeared from these different habitats. But a brand new census from conservation non-profit Fauna & Flora International discovered that Khau Ca’s inhabitants has greater than tripled since 2002, with 160 of the critically endangered monkeys — an estimated 80% of your complete species — now dwelling in the reserve.
“It’s one of our most successful surveys,” says Chu, the project manager for Fauna & Flora’s Tonkin snub-nosed monkey program.
The survey’s findings are giving the delicate species a hope for survival — and may very well be a mannequin for different forests in Vietnam to revive their populations of Tonkin snub-nosed monkeys.
Despite their outlandish facial markings, these monkeys are shy and reserved, avoiding people and sometimes disappearing at any uncommon sounds, says Chu.
It’s a part of what makes them so tough to depend, an issue that goes back a long time.
Hunted extensively to be used in conventional drugs, and typically bushmeat, Tonkin’s snub-nosed monkeys had been so hardly ever seen that by the Eighties, many thought they had been extinct.
Shortly after discovering the inhabitants at Khau Ca, Fauna & Flora arrange a conservation subject station, and established group conservation groups to guard and patrol the forest, serving to to take away snares and report indicators of unlawful deforestation or looking.
To assist communities that may usually make their earnings from farming or foraging in the forest, the challenge additionally creates new earnings streams, just like the patrol teams. Other conservation companions, just like the New Nature Foundation and Denver Zoo, are additionally working to cut back calls for on the forest, distributing fuel-efficient stoves that cut firewood needs by 50%.
Tran Van On, a member of Fauna & Flora’s group conservation workforce, has noticed a “significant increase” in group consciousness across the conservation of the Tonkin snub-nosed monkey.
“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,” stated On, in a written assertion.
The latest survey, carried out in October and November 2025, is essentially the most complete and full so far, says Chu.
More than 30 individuals from the conservation unit and area people divided into 10 teams, tenting in the forest for 10 days to conduct the survey throughout the park’s 1,000-hectare space.
This is a part of a brand new methodology, explains Chu: with the reserve map divided into sections, every group is chargeable for one “cell,” to assist keep away from duplication and enhance effectivity.
The groups additionally utilized thermal imaging drones, digital camera traps, and audiomoths, a sensible acoustics sensor used to watch wildlife and useful to detect the monkey’s distinctive calls.
For Chu, although, who has labored on the challenge for seven years, it’s simple to identify the person monkeys: “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.”
Khau Ca’s latest survey stands in stark distinction to at least one carried out in Quan Ba, beforehand residence to the second-largest inhabitants.
According to Chu, patrollers in Quan Ba haven’t seen the species since 2020, and in its most up-to-date survey in 2024, they discovered no sign of the monkeys.
The largest downside, says Chu, is cardamom farming in the forest. Cardamom, a prized spice for meals and drugs, can present a good income. But its cultivation entails clearing bushes to cut back the dense cover cowl and chopping bushes for firewood to dry the fruits after harvest, degrading the forest ecosystem that species just like the Tonkin snub-nosed monkey have to survive.
When a powerful inhabitants was first discovered there in 2007, Fauna & Flora established three group conservation groups in the realm to assist with safety and patrols, says Chu. But not like Khau Ca, Quan Ba just isn’t a formally protected space, which limits what organizations can do in phrases of long-term habitat administration and protecting restrictions.
But Fauna & Flora hasn’t given up on Quan Ba: it nonetheless maintains one patrol group there, as a result of “the area is so big, that the chance to see them is very low — so we think they have not 100% disappeared,” says Chu.
Currently, the non-profit is creating wildlife corridors from Khau Ca, which it hopes will in the future join with Quan Ba.
“The biodiversity is very rich there, especially related to amphibian and reptiles,” says Chu.
“But one thing is for sure — if we consider it as the second area (for the monkeys), we have to put more action on protection, and try to reduce the presence of the people inside the forest.”