Ebola, poaching threaten wild apes

Hunting and the Ebola virus have halved the wild chimpanzee and gorilla population in west equatorial Africa in 20 years, conservationists say.

The large-scale study warns that without immediate improvements in anti-hunting law enforcement and Ebola prevention, the wild apes will be pushed to the brink of extinction.

"The species that are most similar to humans are just disappearing before our eyes," said Peter Walsh, a visiting research fellow at Princeton University and co-author of the study, which appears in Monday's online issue of the journal Nature.

The dense jungles of Gabon and the Republic of Congo are thought to hold most of world's common chimpanzees and about 80 per cent of its gorillas.

The researchers said previous population estimates were flawed because they did not consider how hunting and disease could deplete the population even in densely forested areas.

Between 60 per cent and 80 per cent of the native forests in the African nations remain intact, but logging has opened up roads that have facilitated the commercial hunting of apes for food, Walsh said.

Between 1998 and 2002, observers travelled through 4,800 kilometres of dense jungle counting ape nests. The counts were compared to the last comprehensive ape survey from 1981 to 1983.

Primates as bushmeat

Poaching accounted for most of the 56 per cent decline in the ape populations. The surveys showed ape populations closest to cities were in greatest danger, as logging employees buy large amounts of so-called bushmeat.

In one remote area of northern Gabon where there is little or no hunting, Ebola has cut the population by more than 90 per cent since 1991.

An ongoing outbreak has killed hundreds of gorillas and chimpanzees near Congo's Odzala National Park over the past few months, said Dr. William Karesh, a veterinarian with the Wildlife Conservation Society and contributor to the study.

The Ebola virus spreads to from apes to humans when humans eat the animals or contact an ape corpse. Ebola has killed about 120 people in Congo during the same period, according to the World Health Organization.

The researchers urged the World Conservation Union to reclassify gorillas and chimpanzees from "endangered" to "critically endangered," meaning both species are expected to suffer "a reduction of at least 80 per cent ... within the next 10 years or three generations."

Russ Mittermeier, chairman of the World Conservation Union's primate specialist group, said he would support the change if it didn't undervalue rarer species of ape such as the mountain and Cross River gorillas. Their numbers have dwindled to the hundreds.