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Thriving population of endangered monkeys gives hope to conservationists

  • Delacour’s langur (Trachypithecus delacouri) is a critically endangered primate species endemic to Vietnam, with only 234-275 estimated remaining today.
  • In response to habitat loss and poaching, local communities teamed up with a German primatologist to form Van Long Nature Reserve.
  • Van Long has effectively protected its langur population, which has quadrupled in size since the reserve was established in 2001. With currently around 200 individuals, the reserve houses the bulk of the world’s remaining Delacour’s langurs.
  • Conservationists hope that more langur habitat will be protected to safeguard other populations from poaching as well as deforestation from agriculture and limestone quarrying for cement production.

While in many places, ecosystems and wildlife are under increasing threat and suffering population declines, Vietnam’s Van Long Nature Reserve provides a light in the darkness. The reserve is home to the largest population of Delacour’s langurs (Trachypithecus delacouri), a critically endangered monkey species endemic to the country and numbering fewer than 300 in the wild today.

Through efforts by local communities along with German primatologist Tilo Nadler, the population has quadrupled since 2000. Now, Nadler is trying to establish more reserves to protect langurs living outside of it that are threatened by deforestation and poaching.

“When I first visited the area in 1993, I discovered a population of about 50 langurs and quickly realized that if we don’t establish a nature reserve, the langurs will soon be gone,” recalls Tilo Nadler, a German primatologist who came to Vietnam on behalf of the Frankfurt Zoological Society to start a primate project in Cuc Phuong National Park.

Van Long Nature Reserve. Image by Tilo Nadler/Endangered Primate Rescue Center.

While working on the primate project (which ultimately resulted in the establishment of the Endangered Primate Rescue Center), Nadler entered into lengthy negotiations with local people who were clearing the forest for firewood, charcoal production and grazing land. He remembers that at one point in time more than a thousand goats were running through the hills. It was clear to him that if the conversion of forest to pasture continued at such a pace, in several years neither goats nor langurs would be able to live in the mountains.

To his great surprise, the leader of the municipality with the highest number of goats decided to heed the conservationists’ warning and within three months had removed all its goats from the mountains.

This part of northern Vietnam is dominated by karst forest, a landscape of limestone eroded over time into dramatic peaks, fissures and caves. However, despite the forest’s seeming inaccessibility, it has been plagued by habitat loss and poaching. In 2001, the government officially protected a 22-square kilometer (8.5-square mile) area known today in English as Van Long Nature Reserve.

Delacour’s langurs (Trachypithecus delacouri) galavant along the limestone outcrops that underlie their forest habitat. However, these outcrops are being eyed by quarrying companies that want to turn them into cement. Image by Tilo Nadler/Endangered Primate Rescue Center.

Yet poaching persisted, so a group of thirty volunteers (mostly farmers but also a few former poachers) was recruited by reserve authorities and Nadler to patrol the area. Research shows that thanks to the protection activities of the Community Protection Unit, no poaching has occurred since then and the population of Delacour’s langur has quadrupled from 50 to 200 individuals over the past 20 years.

With only between 234 and 275 individuals left in the wild, this means that most of the world’s remaining Delacour’s langurs live in Van Long Nature Reserve.

Fewer than 300 Delacour’s langurs (Trachypithecus delacouri) remain today. Image by Tilo Nadler/Endangered Primate Rescue Center.

Of Vietnam’s 120 protected areas – including 30 national parks – Van Long Nature Reserve has so far been the only one to achieve a coveted spot on the IUCN Green List of Protected Areas, which denotes places that have been particularly successful in their conservation goals. Being an important refuge for migratory birds and a breeding ground for water birds, the reserve is also regarded as a “wetland of international importance” by the Ramsar Convention.

To provide a long-term habitat for the survival of Delacour’s langurs in Vietnam, Nadler would like to expand the 3,000-hectare reserve by 1,000 hectares immediately to the north in a neighboring province where around 30 langurs live. He has been negotiating the extension with the Vietnamese authorities for more than 10 years. Even though the locals support his idea (this area has already been under the protection of local municipalities), he says there are bureaucratic and administrative obstacles and an extension of Van Long is unrealistic. Instead, a separate reserve would likely need to be established.

“The border of a province is a very strict concept in Vietnam,” Nadler said. “Sadly, there is no possibility of extending the reserve to another area. A new nature reserve with its own headquarters and rangers will have to be established which will be a waste of energy, time and people.”

Satellite data from the University of Maryland show negligible forest loss in Van Long over the past 20 years. However, areas to the north that Nadler and other conservationists would like to see protected have experienced recent incursions.
Satellite imagery shows an area of recent forest loss in an area just north of Van Long Nature Reserve that Tilo Nadler and other conservationists are hoping will be turned into a reserve in 2021 or 2022.

In cooperation with the Ostrava Zoo, Nadler is working on a biological inventory that will highlight the value of the area and provide background for the establishment of another adjacent protected area to the provincial government and the Ministry of Agriculture and Rural Development.

While Nadler expects the new reserve to be established in 2021 or 2022, there is another population of about 80 Delacour’s langurs living in an area about 5 kilometers (3 miles) north of Van Long that he would also like to see protected. The area is under pressure from limestone quarrying by the cement industry, and satellite imagery shows quarrying pressing into langur habitat.

Satellite imagery shows what appears to be quarrying expanding into an area of primary forest where an estimated 80 Delacour’s langurs are thought to live.

Many national and international conservation organizations are involved in work aimed at reducing habitat loss from quarrying, including Fauna & Flora International, the Centre for Biodiversity Conservation and Endangered Species, the IUCN SSC/Primate Specialist Group, the Central Institute for Natural Resources and Environmental Studies, WWF, the Center for Nature Conservation and Development, Frankfurt Zoological Society and the Centre for Resources, Environment and Climate Change. In September 2020, these groups sent a petition to the office of Vietnam Prime Minister Nguyen Xuan Phuc asking for his support in the conservation of critically endangered and endemic primate species in this area. Nguyen has reportedly ordered the provincial administration to discuss the issue.

The UNESCO World Heritage Site Trang An, located in the same province, is another spot where Nadler wants to establish a viable population of Delacour’s langurs. In 2020, he launched a pilot program with the Endangered Primate Rescue Center and reintroduced three langurs to this site. In the long-term, the center hopes to relocate more langurs from unprotected areas to Trang An. This may also include animals from Van Long Nature Reserve if the capacity of the reserve reaches its limit.

Even though many areas of habitat in Vietnam are shrinking, Nadler is optimistic about the future. However, he says that for langurs and other threatened species in the country to survive in the long-term, the country needs to more strictly enforce environmental protection.

“There are enough habitats for Delacour’s langurs because unlike elephants or tigers they don’t need big areas,” Nadler said. “But we absolutely need to reduce poaching. Raising awareness with flyers won’t help, the only thing that is effective is strict law enforcement and high prosecutions.”


Banner image: Delacour’s langur by Tilo Nadler/Endangered Primate Rescue Center.

Editor’s note: This story was powered by Places to Watch, a Global Forest Watch (GFW) initiative designed to quickly identify concerning forest loss around the world and catalyze further investigation of these areas. Places to Watch draws on a combination of near-real-time satellite data, automated algorithms and field intelligence to identify new areas on a monthly basis. In partnership with Mongabay, GFW is supporting data-driven journalism by providing data and maps generated by Places to Watch. Mongabay maintains complete editorial independence over the stories reported using this data.

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