Monkeys and other primates dying off due to habitat loss and hunting.

The first comprehensive review in five years of the world's 634 kinds of primates found that almost 50 percent are in danger of going extinct, according to the criteria of the IUCN Red List of Threatened Species.

The main threats are habitat destruction, particularly from the burning and clearing of tropical forests that also emits at least 20 percent of the global greenhouse gases causing climate change, and the hunting of primates for food and an illegal wildlife trade.

"We've raised concerns for years about primates being in peril, but now we have solid data to show the situation is far more severe than we imagined," said Russell A. Mittermeier, president of Conservation International (CI) and the longtime chairman of the IUCN Species Survival Commission's Primate Specialist Group. "Tropical forest destruction has always been the main cause, but now it appears that hunting is just as serious a threat in some areas, even where the habitat is still quite intact. In many places, primates are quite literally being eaten to extinction."

Situation bad in Asia

With the input of hundreds of experts worldwide, the primate review provides scientific data to show the severe threats facing animals that share virtually all DNA with humans. In both Vietnam and Cambodia, approximately 90 percent of primate species are considered at risk of extinction. Populations of gibbons, leaf monkeys, langurs and other species have dwindled due to rampant habitat loss exacerbated by hunting for food and to supply the wildlife trade in traditional Chinese medicine and pets.

"What is happening in Southeast Asia is terrifying," said Jean-Christophe Vié, Deputy Head of the IUCN Species Program. "To have a group of animals under such a high level of threat is, quite frankly, unlike anything we have recorded among any other group of species to date."

Important for ecosystems

As our closest relatives, nonhuman primates are important to the health of their surrounding ecosystems. Through the dispersal of seeds and other interactions with their environments, primates help support a wide range of plant and animal life in the world's tropical forests. Healthy forests provide vital resources for local human populations, and also absorb and store carbon dioxide that causes climate change.