Catastrophic decline of Africa’s apes, Nature says

Logging, illegal hunting, and Ebola caused nearly 60 percent decline since 1983

Scientists say chimps and gorillas now ’critically endangered’

Scientists from the New York-based Wildlife Conservation Society, Princeton University and other organizations have reported in the latest issue of the journal Nature that a dramatic decline of gorillas and chimpanzees is taking place in western equatorial Africa, the last stronghold for great apes on the continent. Ravaged first by a wave of commercial hunting, and more recently by an outbreak of the deadly Ebola virus, gorillas and chimpanzees could be pushed to the brink of extinction during the next decade without immediate protective measures, scientists warn.

Looking at populations in the central African nation of Gabon, which still retains 80 percent of its forest cover, scientists discovered a 56 percent drop in chimpanzee and gorilla numbers had taken place between 1983 and 2000. Such a decline justifies that both species should be reclassified from “endangered” to “critically endangered” according to World Conservation Union criteria, the authors of the study say.

“This is a catastrophic decline of great apes in an area that contains the bulk of the world’s remaining populations. If chimps and gorillas continue to disappear at the current rate, our closest relatives will be confined to a few small pockets in a matter of years,” said the paper’s lead author, Dr. Peter Walsh, a WCS biologist based at Princeton University.

“If chimpanzees and gorillas are in trouble in Gabon, an area known for its pristine, unbroken forests, than we have a species-wide crisis on our hands when it comes to saving these animals,” said WCS conservationist Dr. Lee White, who has worked in Gabon for the past decade. Dr. Walsh and his colleagues say that aggressive investments in Ebola prevention, law enforcement and protected area management are needed to ensure the survival of these two species. The head of WCS’s Field Veterinary Program, Dr. William Karesh, says that experts agree that expanded field research on Ebola transmission in wildlife populations is urgently needed, as current knowledge is inadequate to intervene effectively in the epidemic. More support is also required to fight the wave of ape poaching that has followed the intrusion of mechanized logging into once remote areas.

Scientists believe the great ape decline is not restricted to Gabon. Neighboring Republic of Congo and other countries in the region have higher human densities and worse deforestation than Gabon. An outbreak of Ebola hemorrhagic fever in Gabon nearly a decade ago may have wiped out tens of thousands of gorillas and chimps. The disease has emerged again more recently in Gabon and the Congo with gorillas and chimpanzees rapidly dying. Scientists also suspect that widespread civil unrest in Democratic Republic of Congo has caused further declines among gorillas and chimps in that region.

“Western equatorial Africa is the last natural refuge for the western gorilla. To see the results of a data-rich study such as this one – it’s mind-boggling how bad this news is,” said Dr. John Robinson, senior vice president of WCS’s International Conservation Programs. “While WCS is already addressing many of the issues affecting great apes including bushmeat hunting, logging and Ebola, clearly this study is a call to action that conservationists have to double their efforts if we want to continue to save great apes in the wild.”