New Rare Primate Groups Found in Cambodia

Sara Goudarzi
for National Geographic News

September 3, 2008

Two new populations of rare primate species, both numbering in the thousands, have been discovered in a Cambodia preserve.

A 2008 survey estimates 42,000 black-shanked doucs and 2,500 yellow-cheeked crested gibbons live in Cambodia's Seima Biodiversity Conservation Area.

"These Cambodian animals represent undoubtedly the largest [known] remaining global populations of either species," said lead report author Tom Clements, a researcher at the nonprofit Wildlife Conservation Society (WCS), which led the survey.

Before this survey, the largest known populations of either species were 600 black-shanked doucs and 200 yellow-cheeked crested gibbons in neighboring Vietnam—the only other country where the two species are found. (See a photo of another rare primate group found recently in Vietnam.)

The primates are listed as endangered on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species.

They are among the more than 70 percent of Asia's primate species in sharp decline.

(See photos of the 25 most endangered primates.)

Animal Spotters

Sporting long white whiskers, the black-shanked douc lives high in the trees and feasts on leaves and fruit.

Yellow-cheeked crested gibbons are also tree dwellers, eating and sleeping in the upper canopy of evergreen forests.

Between 2005 and 2008, Clements and his team conducted annual surveys in a 300-square-mile (789-square-kilometer) area of Cambodia.

The surveys are the first known attempts to obtain accurate population estimates for the region's native wildlife.

"Although we expected to find a reasonable number of animals, based on the frequency of ad hoc sightings in previous years, we did not anticipate that both primate species would be present in such considerable numbers," Clements said.

Comparisons with other areas suggest that both species are at or near carrying capacity, the maximum number of animals that the habitat can support.

"This suggests that other adjacent areas, which have much lower densities, could support equivalent numbers of animals if successful conservation programs [such as those in Seima] were established," Clements said.

Conservation Success

Hunting and deforestation are among the greatest threats to the newfound primates, experts say.

The survey also highlights the success of establishing conservation programs like the Seima preserve.

"These animals have probably been maintained in Cambodia due to a combination of factors—principally the area's inaccessibility, successful protection of the habitat by the logging concessionaire in the 1990s, and more recently the government-backed conservation program," Clements said.

Patricia Wright is the director of the Institute for the Conservation of Tropical Environments at Stony Brook University in New York State.

She believes the find is an indication of the potential of biodiversity in the region, where resources should be safeguarded.

"This region where [the two species] were found is an unexplored area, filled with forests on steep karst [limestone] mountains," a habitat which these leaf-eating primates specialize in, said Wright, who is on the advisory board of the
National Geographic Conservation Trust. (National Geographic News is owned by the National Geographic Society.)

"There is much work ahead to make sure this habitat and these new populations of these rare primates are protected for the future."