Feared extinct, obscure monkey rediscovered in Borneo

Jeremy Hance
January 20, 2012

Family group of Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.
Family group of Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.

A significant population of the rarely seen, little-known Miller's grizzled langurs (Presbytis hosei canicrus) has been discovered in Indonesian Borneo according to a new paper published in the American Journal of Primatology. Feared extinct by some and dubbed one of the world's 25 most threatened primates in 2005 by Conservation International (CI), the langur surprised researchers by showing up on camera trap in a region of Borneo it was never supposed to be. The discovery provides new hope for the elusive monkey and expands its known range, but conservationists warn the species is not out of the woods yet.

"[The discovery] reinforced my belief in the power of camera traps to transform conservation research," Brent Loken executive director of the conservation NGO Ethical Expeditions and Ph.D student at Simon Fraser University Canada, told mongabay.com. "Because of the cryptic nature of this monkey only a handful of photographs previously existed and descriptions were all based on museum specimens. However, using camera traps we were able to record 4,130 photographs of this extremely rare monkey in only 66 camera trap days."

Loken and his team rediscovered the langur in Wehea Forest in Eastern Kalimantan during a camera-trap survey. Numerous photos show family groups congregating at mineral licks and interacting socially.

Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.
Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.
"To date, Wehea is the only location where Miller’s grizzled langur is known to exist. This discovery brings the total number of non-human primates discovered in Wehea up to ten, making it a primate hot-spot," says Loken.

In addition to Miller's grizzled langur, the forest is also home to Bornean orangutans (Pongo pygmaeus), listed as Endangered, the maroon langur (Presbytis rubicunda), gibbons and macaques. The Sunda clouded leopard (Neofelis diardi), marbled cat (Pardofelis marmorata), and sun bear (Ursus malayanus), all three listed as Vulnerable, also roam the forest.

Spread over 38,000 hectares, Wehea is mostly undisturbed, intact forest. Currently protected by the indigenous Wehea Dayak people, aided in part by Ethical Expeditions, the area is currently a stronghold for endangered Bornean wildfire.

"Given that Wehea is patrolled by a dedicated team of local Wehea Dayak forest guardians and that Wehea is contiguous with other large forested areas, this could potentially be one of the last 'safe' homes for [Miller's grizzled langur]," says Loken.

However, despite being declared "protected" but its indigenous people, Wehea forest is still shown as a logging concessions on maps and has not been awarded any official government protection. Like many forests in Borneo, the region faces constant peril.

"Until this legal status is given, there is always a threat that Wehea Forest could be converted to other land uses," Loken says.

Co-author Stephanie Spehar, a professor of Anthropology at University of Wisconsin Oshkosh, told mongabay.com that any one of numerous threats could imperil the area, its wildlife, and people: "Wehea, like much of the forest in East Kalimantan, is threatened by human activities such as logging, oil palm plantations, and coal mining. [It] is currently protected by the commitment and hard work of the local Dayak community and the support of the local government, but this protection is not yet permanent. We need to continue to work to ensure that Wehea and other forested regions in this area receive the protection that they need, and we also need to pursue strategies that will address the larger issues of land and resource use in the region."

Stephanie Spehar adds that the serendipitous discover of Miller's grizzled langur in Wehea has given scientists, for the first time, the opportunity to observe the monkey.

Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.
Miller's grizzled langur in Wehea Forest. Photo by: Eric Fell.
"We will now be able to begin studies of the ecology and behavior of this endangered primate. Such information is crucial for conservation planning but currently very little is known about Miller's grizzled langur. We hope to rectify this with further surveys and studies of its behavior in Wehea and the surrounding area, which we will begin later this year."

Still, the happy find does not mean Miller's grizzled langur is safe from extinction. Like many species on the island—devastated by habitat loss—Loken expects the species is still very endangered. Researchers will begin by estimating the species' density in the forest.

"It is a race against time to protect many species in Borneo," Loken says in a press release. "It is difficult to adopt conservation strategies to protect species when we don’t even know the extent of where they live. We need more scientists in the field working on understudied species such as Miller’s grizzled langur, clouded leopards and sun bears."

Ethical Expeditions and Loken are currently working on a research and conservation program on the Sunda clouded leopard, a large cat that was only classified as a separate species from the mainland clouded leopard in 2006.

"Borneo is a biodiversity hotspot," Spehar adds, "and this discovery underscores the importance of preserving wildlife habitat in Borneo, and in East Kalimantan in particular—who knows what else is out there?"

CITATION: Lhota, Stanislav, Loken, Brent, Spehar, Stephanie; Fell, Eric, Pospech, Alexandr; Kasyanto, Nunuk. Discovery of Miller's Grizzled Langur (Presbytis hosei canicrus) in Wehea Forest confirms the continued existence and extends known geographical range of an endangered primate. American Journal of Primatology. Wiley-Blackwell, January 2012, DOI: 10.1002/ajp.21983.

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Jeremy Hance
mongabay.com (January 20, 2012).

Feared extinct, obscure monkey rediscovered in Borneo .