NEW YORK -- The orangutan - the only great ape found in Asia - may vanish from the wild within a decade, unless illegal logging of its habitat and poaching can be greatly reduced, according to research funded by the Bronx Zoo-based Wildlife Conservation Society (WCS).
The study, which appears in the current issue of the journal Oryx, documents the tremendous decline in orangutans throughout their range. The Leuser Ecosystem in northern Sumatra, Indonesia, which supported 12,000 orangutans in 1993 -- the largest population in the world -- lost nearly half its animals over a seven year period. In 1998 and 1999, losses occurred at around 1,000 animals per year.
"The alarming decline in Leuser's orangutan numbers implies that the world's largest natural orangutan population will be extinct in a decade or so, unless the current trend is stopped," said the study's lead author, Dr. Carel van Schaik, a WCS research associate from Duke University who has studied wild orangutans for more than 20 years.
Ironically, the Leuser Ecosystem includes Sumatra's largest protected area, Leuser National Park, where rampant logging is backed by the Indonesian military and police. "All remaining forests that are accessible by road or river are subject to a seemingly unstoppable pandemic of illegal logging, regardless of their protection status," van Schaik said.
Van Schaik found that orangutan densities decreased more than 60 percent in areas that have been selectively logged, due mostly to a decline in trees that produce fruit - a critical food source for orangutans - as well as the loss of canopy trees they use for travel. The rampant illegal logging that inevitably follows selective cutting in Leuser and other areas, has caused densities to drop as much as 90 percent. Many areas are subsequently turned into massive agricultural estates, and therefore do not regenerate into forest.