Deep in a pristine Borneo rainforest, researchers have found an endangered species of monkey recently feared to be extinct.
Surveys in the late 1970s spotted the monkey, called Miller’s grizzled langur, in Borneo’s easternmost national forest. Three decades later, all but 5 percent of the habitat had been destroyed by logging, agricultural encroachment, coal mining and fire.
As late as 2011, many researchers feared the langur was extinct. One place they hadn’t searched intensively, however, was Wehea — a rainforest preserve 90 miles west of the langur’s traditional territory.
Armed with camera traps and some luck, a survey team accidentally captured the first images of grizzled langurs in years.
“Locals knew they lived in this forest but had no idea what they were looking at. When we saw them, we were shocked,” said conservation scientist Brent Loken of Simon Fraser University, co-author of a study published online Jan. 20 in the American Journal of Primatology.
Little is known about the grizzled langurs, scientifically known as Presbytis hosei canicrus. Loken and his colleagues will have a prime opportunity to study the exceedingly rare monkeys, but they will have to move quickly.
“There’s still intense debate of whether or not the Indonesian government will grant legal protection status for Wehea,” Loken said. “You could say this is very good timing for the rediscovery.”
Tropical forests across Indonesia are among the most biodiverse places in the world. Orangutans, clouded leopards, pygmy elephants and other rare animals all call Borneo’s rainforests home. Miller’s grizzled langur is the most poorly understood of all Borneo primates and, as a member of the IUCN’s critically endangered species list, is also the rarest.
With the permission of the indigenous Dayak people, Loken and colleagues set up camera traps and observation blinds at two sepans, or locations where animals congregate to lick mineral-rich salts seeping from springs in the ground. They originally hoped to see an elusive clouded leopard; in the course of 10,000 photographs, none showed, but the langurs did.
Stephanie Spehar, a primatologist at the University of Wisconsin in Oshkosh, said the adult langurs weigh between 13 and 16 pounds, munch primarily on leaves and tend to live in groups of one male, several females and their infants. She said it’s too soon to estimate their population size.At first, Loken and his colleagues weren’t sure what they’d found. No previous photographs existed, so they had to find museum specimens for comparison.
“We know almost nothing about this species or its ecology,” Spehar said. “I’m incredibly eager to begin the long-term ecology studies. That information will be crucial to their preservation.”
The discovery continues a recent streak of rediscovering animals once thought to be extinct, includingsnub-nosed monkeys in China, the Galapagos islands’ giant tortoise and a rainbow toad.
But while the langur’s rediscovery is certainly good news, its survival hangs in the balance.
The Indonesian government has worked with both local and international conservation groups to protect its ancient forests and support sustainable practices. Corruption is a problem, however, and bribery by logging, palm oil and mining companies allow laws to be evaded. More than half of Borneo’s original forests have vanished since the 1950s.
“The laws in the book are quite good. However, the enforcement of those laws is more problematic,” Loken said. “If companies do what they’re supposed to do, particularly logging companies, these forests and the langurs stand a chance of recovering.”
Photos: Eric Fell
Citation: “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.” Stanislav Lhota, Brent Loken, Stephanie Spehar, Eric Fell, Alexandr Pospěch and Nunuk Kasyanto. American Journal of Primatology, January 20, 2012. DOI: 10.1002/ajp.21983