• In Malaysia’s Penang state, conservationists and residents are collaborating to reduce conflict between humans and endangered dusky langurs displaced by urban development and habitat loss.

• The Langur Project Penang built a canopy bridge to help langurs safely cross a busy road and access more habitat, reducing time spent in residential areas and lowering complaints from residents.
• Malaysia’s wildlife agency receives thousands of wildlife complaints annually, and often responds with trapping, relocation or culling; but conservationists argue education and coexistence measures can be more sustainable responses to increasing human-wildlife encounters.

• The project’s success has depended heavily on local support and citizen scientists, with some residents gradually shifting from frustration toward compassion and acceptance of living alongside wildlife.

TANJUNG BUNGAH, Malaysia — The 50-year-old mango tree growing through Tan Soo Siah’s second-story terrace is a favorite stopping place for the family of endangered monkeys that has taken up residence in a small park near his home in Malaysia’s Penang state.

“Since everybody chases them away, I try to let them have a rest here,” says Tan, 64, who likes to watch the dusky langurs (Trachypithecus obscurus) from his bedroom window, peeking up at them playing in the foliage.

Not everyone in Taman Concord, a residential community home mostly to retirees like Tan, is as taken with the langurs as he is. Around three years ago, the monkeys were inciting complaints from seniors who were fed up with langurs leaping across their houses, damaging their rooftops and denuding their gardens.

Perhilitan, Malaysia’s wildlife agency, was summoned. The agency’s typical methods for dealing with “conflict” animals include installing deterrents, trapping and relocation, and, as a last resort, culling.

This time, Perhilitan called the Langur Project Penang (LPP), a social enterprise founded by Malaysian primatologist Yap Jo Leen.

Yap’s team of citizen scientists spent months diagnosing the problem, tracking the monkeys’ movements and interviewing local residents. The group ultimately built a canopy bridge made from old fire hoses to help the langurs safely cross a busy road and expand their range, relieving pressure on Taman Concord.

Today, Tan and his neighbors are learning to live with the langurs, who regularly use the bridge, known as Numi’s Crossing, named for a young langur that met his end after repeatedly falling from slippery power lines during LPP’s fieldwork.

‘I don’t keep the window open anymore’

Peninsular Malaysia has lost more than half its forest cover since 1900, as its human population has climbed from 1.7 million to 25 million. What jungle remains is increasingly fragmented by roads and buildings, pushing wildlife into ever more frequent contact with humans.

Perhilitan receives around 5,000-13,000 wildlife complaints a year. Invariably topping the list of species people call them about is the long-tailed macaque (Macaca fascicularis), the gray-brown monkey commonly found near roadsides and tourist sites. Its boldness around humans has earned it the reputation of being a nuisance, but the species is in fact listed as endangered on the IUCN’s Red List.

Last year in Port Dickson, a fast-growing beach town south of Kuala Lumpur, Azizah Abbas was alone in her home reciting the Quran when she heard a loud noise in the next room. She went in to find a pair of macaques devouring her Eid cookies. Horrified, the 84-year-old picked up a wooden stick and chased them around the living room, resulting in two broken bowls before they scampered out the window they’d come in through.

“I don’t keep the window open anymore,” says Azizah, who’s also resigned herself to no longer cultivating fruit in her garden in favor of bitter-tasting plants like betel (Piper betle) and sacha inchi (Plukenetia volubilis) that the macaques won’t eat.

Langurs are shyer than macaques, preferring to spend more time in the trees, but they aren’t above the occasional foray into human settlements. Perhilitan recorded 196 dusky langur complaints in 2021, the last year it published data.

One of those complaints led to a now-notorious incident at a school in Port Dickson, where wildlife officers allegedly shot and killed 20 dusky langurs, including a mother and baby. Perhilitan says it only killed seven aggressive monkeys after trapping efforts failed. This past February, Malaysia’s Court of Appeals ruled the killing of the entire group to be unlawful, in a suit filed by animal welfare advocates.

Perhilitan culls tens of thousands of long-tailed macaques every year, according to its annual reports. The agency culled 904 langurs in 2010, the only year it has published culling figures for langurs.

Dusky langur numbers are suspected to have declined by more than 50% over the past three generations throughout the species’ range in Singapore, Peninsular Malaysia and the south of Thailand and Myanmar, pushing it into endangered status.

‘Safe haven’

Taman Concord is a grid of some 150 low-slung rooftops in the center of Tanjung Bungah, a suburb of state capital George Town tucked between the northern coast of Penang Island and a ridge of forested hills to the south.

When Yap Jo Leen and her citizen scientists arrived in Taman Concord in 2023, residents were asking if the langurs had become “trapped” in the housing estate by the wave of development sweeping through Tanjung Bungah. High rises, other buildings and a quarry had come up in the kilometer-wide (0.6-mile) area between Taman Concord and the hills to the south, seemingly cutting the langurs off from their natural habitat.

“‘All of you should bring the langurs back to the forest’ — that was the usual script that people used to say to us,” Yap says.

But moving the langurs, a practice known in conservation parlance as translocation, wasn’t necessarily feasible. Langurs are harder to capture than macaques. Even if you can trap them, a suitable release site must first be identified, one with enough food and no monkeys already living there, since fighting between groups could drive more monkeys into human settlements. Indeed, the langurs in Taman Concord, a group of eight, were led by a male who had broken his tail in a clash with another group, Yap says.

As they observed the langurs, the researchers noticed they would often try to cross a treacherous stretch of Jalan Lembah Permai, a road that widens to several lanes as it straightens out just south of Taman Concord. The langurs would begin to dart across, only to freeze in the middle and turn back. Sometimes they would cross via a culvert underneath the road, where they might encounter dogs that could rip them to shreds. When they did make it across, they didn’t venture far, sticking to a patch of trees by the roadside.

After six months of fieldwork, LPP proposed the canopy bridge. LPP had previously built one elsewhere on Penang Island, on a road where at least eight dusky langurs died in traffic accidents between 2016 and 2018. Since LPP put up a bridge there in 2019, no langur deaths have been recorded in that area.

The bridge in Tanjung Bungah has helped the eight langurs in Taman Concord access more territory, and they now spend less time in the housing estate, LPP has observed.

“They have more opportunity to venture closer to the hills … and find their way to a safe haven,” Yap says.

As a result, complaints from Taman Concord “have decreased tremendously, because the bridge has helped that group of monkeys move toward the other side,” says Wong Hui Yi, LPP’s project executive.

The neighborhood into which the langurs have expanded is home to younger people who tend to commute to work, and so don’t encounter the monkeys as often — something LPP learned from interviewing around 130 people in Taman Concord and two adjacent communities before pitching the bridge idea.

Numi’s Crossing is the first canopy bridge in a high-density urban area in Peninsular Malaysia, which already has “ecological viaducts” to help larger mammals cross some rural highways.

This past April, after LPP installed a third canopy bridge in Batu Ferringhi, another part of Penang Island, Syed Ibrahim Syed Noh, Malaysia’s deputy minister of natural resources and environmental sustainability, visited the site and said the ministry would study wider use of canopy bridges.

“The initiative by LPP has the potential to be an effective and animal-friendly solution,” Syed told journalists. “However, it requires thorough evaluation before being expanded to other areas.”

Mr. Tan’s neighborhood

While Numi’s Crossing has alleviated the pressure on Taman Concord, it hasn’t been a cure-all. The langurs still frequent the neighborhood, and some residents still gripe about them.

“I think they will multiply more and more if you don’t kill them,” one local man told LPP recently, according to field notes the group shared with Mongabay.

Langur incursions are a relatively new phenomenon in this part of Penang, so people assume the monkeys must be spreading out of control, says Teo Hoon Cheng, head of LPP’s environmental education program.

“Actually it’s the other way around — you see them more often because of the habitat loss, that’s why they come to your place,” says Teo, a former IT manager who first joined LPP as a volunteer citizen scientist.

Teo tries to teach residents how to deal with the langurs in a more humane way. Don’t feed the langurs, he instructs them. Be sure to properly dispose of your garbage. No need to scare them off with firecrackers, as some have tried; just spray them with water, make a loud noise, or bang a stick on the ground to make them scatter as you walk past. Don’t look them in the eye or show your teeth, even if you’re smiling at how cute they are, as they’ll interpret that as a challenge or a sign of fear.

“Some [people], they don’t really know what to do. So now we are educating them and they get some ideas of how to protect themselves and also to be kind to those animals,” says Lim Hock Cheng, head of the Village Community Management Council (MPKK) in Batu Ferringhi.

For others in Taman Concord, understanding why the langurs are here and how to safely engage with them when they must has made them more sympathetic, Wong says. Some say they miss the langurs now that they don’t come around as much.

“I would say they develop some sense of compassion and kindness towards animals,” Wong says. “And they are slowly accepting that this is the situation of coexistence that we need to practice.”

Tan helps out, calming things down with his neighbors when tensions flare. A retired graphic designer, he’s joined some of LPP’s meetings with local government officials and keeps an eye on the bridge itself, which is important for its maintenance. The citizen scientists, who range in age from 17 to 65, have named the alpha male after Tan, and now refer to the pack of eight langurs as “Ah Tan’s group.”

Support from locals has been key to the success of the project, says Nadine Ruppert, vice president of the Malaysian Primatological Society, who advised Yap on her Ph.D.

“She has this little army of citizen scientists who are very invested in the project,” Ruppert says. “I think that’s really beautiful and really the essence of successful conservation projects: to have a long-term impact, you have to have the people feel happy and involved in it.”

Tan says he doesn’t get to eat very many of his mangoes these days. But for him, the langurs are the real treat.

“When we go to another country, you have to pay to see the wildlife,” he says on his terrace, with a view of steel cranes rising over concrete and green hills in the distance. “I’m so lucky they’re here.”

Banner image: A female dusky langur with her baby crosses an artificial canopy bridge called Numi’s Crossing along Lembah Permai road in the Tanjung Bungah area of George Town, Penang Island. Image by Mohd Rasfan / AFP.

This article is part of a reporting project between Mongabay and Agence France-Presse (AFP).