Site icon Conservation news

Where have all the lutungs gone? Mystery monkeys fast disappearing

Phayre’s leaf monkey (Trachypithecus phayrei) an Endangered species of lutung found in Southeast Asia. Photo by tontantravel: Attribution-ShareAlike 2.0 Generic

  • Asia boasts 16 species of lutung, in two ranges, one in south central and Southeast Asia (northeast India, southern China, Taiwan, Borneo, Thailand, Java and Bali), and the other at the southern tip of India and on Sri Lanka.
  • Lutungs are tree dwellers, threatened by a rapid loss of tropical forests due to oil palm plantations, logging, and human population growth; the animals are also illegally hunted for bushmeat, traditional medicine and the pet trade.
  • Like so many Almost Famous species, lutungs suffer from a lack of publicity, research, funding and local concern. Except for a few species, most are protected accidentally, when a forest in which lutungs live is preserved by a government or NGO trying to protect charismatic megafauna.
  • Of the 16 lutung species, the IUCN assesses 4 as Vulnerable, 2 as Near Threatened, 7 as Endangered, 2 as Critically Endangered, and one as suffering from insufficient data for a conservation assessment. While surveys are lacking, all lutungs are known to be in decline, some alarmingly.
A baby Javan lutung (Trachypithecus auratus). Photo by tom_bream07: Attribution-ShareAlike 2.0 Generic License

When I mentioned to some friends that I was writing a piece for Mongabay about langurs, their perplexed reactions were similar: “I thought you were an environmental journalist?” they said. “Why are you writing about long, tedious passages of fiction? Are you that into Henry James?”

When I assured them that rather than longueurs I was writing about langurs, an Old World family of monkeys, included within the lutung genus — animals facing daunting environmental challenges — I drew blank responses.

And in researching this story, I began to understand that is exactly why these animals are in trouble: For all the noble public enthusiasm regarding the preservation of the great apes — the chimpanzees, bonobos, gorillas and orangutans — these smaller versions of our fellow primates lie mostly outside our global environmental consciousness.

But as I’ve learned, these little monkeys, classified among the so-called “lesser apes”, have suffered as much from human encroachment, and are as much in need of our immediate aid, as are our larger, closer primate kin.

So, what’s a langur, or a lutung?

The taxonomy of these creatures is a bit confusing, as befits — or perhaps contributes to — their obscurity.

All Old World monkeys belong to the Family Cercopithecidae. The Subfamily Colobinae contains the langur or “leaf monkey” grouping, in which is included the Genus Trachypithecus, the lutungs. This genus in turn contains sixteen species endemic to two distinct ranges, one in south central and Southeast Asia (northeast India, southern China, Taiwan, Borneo, Thailand, Java and Bali), and the other confined to the southern tip of India and parts of Sri Lanka.

Gray langurs, also known as Hanuman langurs, with young. They are the most widespread langurs of South Asia. Long lumped together as one species, but now recognized as several distinct species. Photo by Atharva Tagalpellewar: Creative Commons Attribution-Share Alike 4.0 International License

Across their diverse ranges, the lutungs share similarities: they’re lithe and slender, with long non-prehensile tails, agile feet and hands that allow them to leap from branch-to-branch in their preferred rainforest canopy habitats. And they are diurnal species, spending the daylight hours plucking leaves and fruit to satisfy their strictly herbivorous diets.

Lutungs’ wide-eyed, bare faces — hooded with lustrous hair of black, white, orange or gray — present an arsenal of facial expressions troublingly similar to our own: emoting what we would recognize as surprise, fear, pleasure and amazement.

These little monkeys live in social units that we call harems, wherein the dominant male mates with several females and the young are raised communally (for lutungs, at least, it really does take a village).

Life in the canopy has not been good to lutungs of late. Of the sixteen species, the Red List of the International Union for the Conservation of Nature (IUCN) assesses four as Vulnerable (the Javan, Nilgiri, Laotian and Capped langurs); two as Near Threatened (the Silvery lutung and Dusky leaf-monkey); seven as Endangered (François’s langur, Gee’s Golden langur, the Indochinese langur, the Hatinh langur, Phayre’s leaf-monkey, Shortridge’s langur and the Purple-faced langur); and two as Critically Endangered — the Delacour’s and White-headed langurs, are balanced on the edge of the abyss. The Tenasserim lutung has insufficient data for a conservation assessment, but as all of these species are known to be declining in numbers, some alarmingly so, it’s a safe bet that this species is doing poorly as well.

Phayre’s leaf monkey (Trachypithecus phayrei) an Endangered species of lutung found in Southeast Asia. Photo by tontantravel: Attribution-ShareAlike 2.0 Generic

Liz Bennett is Vice President for Species Conservation with the Wildlife Conservation Society, and one of the world’s few experts on this generally unfamiliar group of monkeys. In an interview with Mongabay, Dr. Bennett said that she “grew up on the edge of London and was always fascinated by wildlife, learning about animals from a young age by going to the London Zoo, watching David Attenborough nature programs on TV, and doing nature walks in the local forest.”

The plight of endangered species led her to study primates in the field for her doctorate from Cambridge. She focused on the ecology of Banded langurs — close relatives to Trachypithecus species — in Malaysia.

I asked Dr. Bennett the central question: what are the chances that this human generation will witness the extinction of a lutung species in the wild?

“Many genera of primates are highly vulnerable to extinction, due to their being relatively large, often conspicuous and, most importantly, having very slow reproductive rates compared to many other species,” she responded. The status of “Trachyithecus species has changed very significantly in recent years, and continues to do so. This places it high up on the genera of concern.”

Her reply was all too familiar; these arboreal animals are threatened by the usual long list of human-caused disruptions afflicting the natural world: “In all places, the species face two primary threats: loss and fragmentation of habitat, and hunting. Habitat loss is for many reasons, including expansion of industry and housing, local agriculture, and especially large-scale industrial agriculture such as oil palm [production]. Fragmentation is by roads, including logging roads. Both potentially form barriers between groups of animals, but more, provide access to hunters. Hunting is for food, pets and traditional medicines.”

“Hunting” here means criminal poaching, as IUCN Red Listed lutung species live in Asian countries that are all signatories to CITES (the Convention on International Trade of Wild Flora and Fauna), making it illegal to kill, harm or trade in endangered species within their borders.

But international environmental laws, like so many other human constructs, are subject to the whims of official corruption, bureaucratic inertia, failed enforcement, economic need, greed, and public indifference that typically result in rapidly vanishing wildlife.

The Endangered Purple-faced langur (Trachypithecus vetulus) is endemic to Sri Lanka. Photo by gailhampshire licensed under the Creative Commons Attribution 2.0 Generic license

Accidental rescue

So what’s being done to save the lutungs, while we still can? “Many government and non-government agencies are working to address this,” Bennett said, offering a bit of hope. “The two core types of activities are: (1) protecting habitats; and (2) enforcement of anti-hunting and trafficking laws.

Both approaches are challenging though, because, apart from a few high profile Trachypithecus species (such as the Cat Ba langur occupying a single Vietnamese island), most lutungs are not prominent on conservation agendas, especially compared to higher profile species such as orangutans or tigers.

“In some protected areas where enforcement through GIS-guided scientific patrol systems are in place (such as the Western Ghats, India; Western Forest Complex, Thailand), Trachypithecus species benefit from good protection — even if [those conservation efforts are] primarily aimed at protecting other high profile species,” said Bennett. “In other places, as far as we know, populations generally continue to decline, although in only a few sites are surveys being done to confirm their status.”

Aside from the tertiary benefits derived from the protection of more charismatic species, then, little is being done for, and little is precisely known about, lutung populations, except for the fact that they are in decline, and, in some cases, even collapsing.

Bedeviled by the pet trade

Unfortunately for lutungs, these species are ill-equipped to protect themselves from the illegal pet trade — that international network of global wildlife traffickers that tear animals from their habitats for a lifetime of bondage and exhibition. One imagines that such captivity must be particularly miserable for the young communally raised lutungs.

Dr. John Fleagle, an anthropologist and primatologist at SUNY Stony Brook, lists the reasons for the prominence of the trade in lutungs: the unusual looking monkeys are easy for traffickers to locate and capture; are attractive to buyers; while locals generally lack any incentive to report wildlife crime. Add to that the money to be made.

Silvery lutungs (Trachypithecus cristatus) with young. The species is found in Peninsular Malaysia, Sumatra and Borneo. Photo by Peter Gronemann licensed under the Creative Commons Attribution 2.0 Generic license

“They [lutungs] are relatively more cryptic [possessing better camouflage coloring] than some other sympatric taxa such as gibbons, but they are slower,” Dr. Fleagle told Mongabay. “They [also] have bright orange babies that attract attention.”

The animals are good at hiding from people, but once seen are slow to escape capture. And with adorably flamboyant babies — sporting lustrous hair and emotionally expressive faces — they must look irresistible in bamboo cages among the stalls of sweltering South Asian street markets.


But for all the harm and suffering brought by the pet trade, along with the inexorable demolition of habitat to make way for agribusiness, it’s the bushmeat trade — the capture of lutungs for food and “traditional medicines” by local people — that Liz Bennett says poses the greatest immediate threat to the lutungs.

“This needs to be addressed through a combination of education and awareness, and enforcement of laws protecting the species against hunting and trade,” she said. But the deeply engrained folkways — prompting the harvesting of these animals for dubiously effective traditional medicines — are tough to counter, especially where there is no funding or conservation organization exclusively focused on the task.

And for the hungry rainforest villager and his family, or perhaps an urban family unable to afford other meat, roasted lutung likely beats a vegetarian meal or going without. After all, most consumers would likely resist giving up the cookies, cakes, imitation dairy creamers, soaps, shampoos and other products that rely on 50 million tons of palm oil produced annually where tropical forests once stood.

An Endangered François langur (Trachypithecus francoisi). The species is native to Vietnam and Southwest China. Photo by Lea Maimone CC BY-SA 2.5

In the face of such intense human demand, and as seen in countries across the world, domestic environmental laws and international treaties are on the books that should stop the slaughter of lutungs and conserve their habitat. But regulations are routinely brushed aside, benefiting moneyed interests, traffickers, hunters, hungry people, and consumers who give little deep thought to the dwindling of a nation’s wild heritage.

Without government accountability and an impartial, politically detached judicial system, the gross inequalities that drive so much of today’s wildlife crime and habitat destruction will almost certainly continue, with animals suffering the brutal daily consequences.

Hope for the lutungs: How did the Golden langur cross the road?

Lutungs needn’t disappear from the world, and it might not take a gigantic international push to save them. In fact, it can be surprising just how effective, clever and inexpensive local conservation strategies can be — as demonstrated by the case of Gee’s Golden langur, found in Assam, in northeast India.

An ingeniously simple tactic being used there to protect there Endangered lesser apes is the ropeway, an aerial wildlife corridor consisting of bamboo and thick ropes that crosses a dangerous highway between two forest patches of the Chakrasila wildlife sanctuary. Wildlife corridors come in all forms, from bridges to tunnels depending on the wildlife being detoured away from deadly roads, but few can be as cheap and efficient as these simple aerial structures connecting habitat far above roaring traffic.

The Endangered Gee’s Golden langur (Trachypithecus geei) found in Assam, India. Photo by Doniv79: Creative Commons Attribution-Share Alike 2.5 Generic License

Naturalists surveyed the road site (where there had been many langur fatalities), and evaluated the best place to put the ropeway. A partnership between the Greater Manas Conservation Project, Bodoland Territorial Council authorities, and the International Fund for Animal Welfare-WTI initiated what they called a Rapid Action Project (RAP). The ropeway was hung 60 meters above the ground. The Golden langurs rejected their aerial walkway at first, then made it their own.

And it even affords eco-tourists spectacular photo ops: Think of it… you’re tooling along, admiring the remnant wild habitat, and a movement catches your eye: you glance up in time to see a Golden langur, self-assuredly crossing the road hand-over-hand above your head.

Most langur conservation strategies are far more complicated, expensive and difficult to manage over time. The key to the preservation of endangered wildlife is to scientifically map out those areas of habitat that are critical to the long-term preservation of each species — areas suitable for sustained generational reproduction, with adequate, reliable natural sources of food and water. Once this critical habitat is located, then land protection must follow. And because langurs are so attractive to traffickers, a determined and amply rewarded law enforcement presence is needed — reliably backed by resolute and uncorrupted legal systems — that remain perpetually on guard against the myriad threats facing these irreplaceable little monkeys.

A Douc langur. Photo by Marian Henderson: Attribution-ShareAlike 2.0 Generic License

One promising project is being run in Cambodia by the Douc Langur Foundation, a fairly recently launched community-based conservation organization that employs local people to guard against poachers, illegal loggers and other threats.

As already mentioned, the international trade in exotic “pets” has been one of the langurs’ greatest challenges, and the Douc Langur Foundation has racked up an impressive record of protection in a short time. A list of their achievements includes:

This is serious and dangerous business — traffickers are typically well armed and hostile — and these underfunded locals deserve credit for the risks they take in defense of their fellow “lesser” primates.

Hanuman langur and baby (Semnopithecus entellus) caught in mid-leap. Photo by Jack Wickes: Attribution-NoDerivs 2.0 Generic License

Another small victory has been scored with another lutung, Vietnam’s Cat Ba langur. Rampant poaching for traditional medicine and “sport” hunting by tourists visiting Cat Ba Island, pushed the species to the brink of extinction. The population in the 1960s was estimated at over 2,500 animals. By 2000, estimates plummeted to about fifty.

Germany’s Allwetterzoo Münster and other organizations established the Cat Ba Langur Conservation Project, a long-term effort to prevent the species from going extinct. The CBLCP employs four full-time people on the island, hunting has been nearly stopped, and the population has slowly rebounded. As of 2015, it was estimated at about 67 animals, though it will take eternal vigilance to keep those numbers growing.

Most people viewing the many species of “lesser apes” in zoos, respond similarly, immediately perceiving these unfamiliar primates as adorable or loveable, but “At the end of the day,” said Liz Bennett, “lutungs will only be conserved if societies value them in the wild, which means that there is support for protected areas, for protecting the wildlife within them, and a reduction in demand for the animals as food and medicine.”

International conservation groups with limited funds and staffs, plus strata upon strata of international and national laws can only do so much. Ultimately, the fate of the lutungs — these fascinating little primates quietly fading from the forest canopy — will probably depend on the caring of those local people with whom, for what time still remains, these creatures share their world.

A Spectacled langur (Trachypithecus obscurus), also known as a Dusky langur, dusky leaf monkey, or spectacled leaf monkey. The species is found in Malaysia, Burma and Thailand. Photo by Lip Kee: Attribution-ShareAlike 2.0 Generic License