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Ebola blamed in tragic decline of great apes

Recent research has revealed that the spread of the deadly Ebola virus has devastated populations of gorillas and chimpanzees, adding new urgency to a meeting designed to formulate a survival strategy for the great apes. By Kari Huus.
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An army of the world’s top primatologists and conservationists will meet in Paris this week to formulate an emergency strategy aimed at saving man’s closest relatives — the great apes. But even as the international forum was being planned, a new tragedy was befalling these endangered species. Recent research has revealed that the spread of the deadly Ebola virus has devastated populations of gorillas and chimpanzees, hastening their relentless march toward extinction.

The Great Apes Survival Project was organized by the United Nations to draw up a strategy to save gorillas, orangutans, bonobos and chimpanzees from the threat of extinction caused by poaching and destruction of their habitat by lumbering, farming and mining interests. The forum will call for 21 African nations and two Asian countries, which are home to the vast majority of these animals, to adopt the strategy. And it will call on wealthy nations and organizations to fund it.

With the emergence of clear evidence that Ebola has swept through core populations of gorillas and chimpanzees in Africa, stopping the spread of the disease is now high on the GRASP agenda and creates yet another demand on scarce funding from donors.

“Ebola is the coup de grace in a way, with so many other problems plaguing ape populations — lumbering, growing population in wilderness areas, and the bush meat trade,” says Richard Carroll, director of Africa programs for the World Wildlife Fund

Kissing cousins
What makes these animals unique is their close connection to humans, sharing more that 96 percent of our genetic make-up. They stand upright and hold things with their human-like hands. Their antics and ability to learn charm and mesmerize humans.

“So close is our relationship (with apes) that a taxonomist from another planet would probably classify humans as another African ape species,” reads a GRASP statement.

But where humans thrive, apes struggle to survive.

The Western lowland gorilla, which until recently had a population estimated at around 94,000, has dropped dramatically from poaching and Ebola, by more than 50 percent across the board, and more than 90 percent in some areas. The number of mountain gorillas, whose plight was dramatized in the 1988 movie “Gorillas in the Mist,” has fallen below 700, says Carroll’s group.

The population of chimpanzees is unknown, but their tropical rainforest habitat is being destroyed at the rate of 110,000 square kilometers a year. In addition to the recent threat of Ebola, chimpanzees are captured in large numbers for commercial purposes, and until recently, for medical research. The total number of orangutans, which live in Southeast Asia, has plummeted to under 27,000 as devastating fires, lumbering, mining and farming continue to gnaw at their forest habitat. The Balikpapan Orangutan Society USA says that failure to check current trends will lead orangutans to extinction in the wild in 10 years.

Catastrophe’ in Minkebe Forest
Concerns about the Ebola threat floated around the scientific community for several years, but only recently took hold as an issue, with research conducted in the isolated Minkebe Forest in 2000, a total area of more than 32,000 square kilometers in northwestern Gabon, at the center of which was about 14,000 square kilometers virtually untouched by humans. Field researchers who conducted reconnaissance, moving painstakingly through the forest on foot, recorded all signs of gorillas and chimpanzees — animal sightings as well as evidence such as nests and droppings.

Analyzing the results of two years of such trips, the researchers published an article this October in the scientific journal Oryx, reporting “a catastrophic decline” in lowland gorilla and chimpanzee populations in the area. Less than 10 percent of the estimated original population was in evidence, and signs strongly suggest the cause was an Ebola epidemic. Because humans so rarely penetrate this dense forest, poaching was ruled out.

This year, there is growing evidence of a serious new outbreak in the Republic of Congo, in and around the Lossi Sanctuary. At the same time, at least 100 people have died of Ebola in two nearby villages. The virus, which causes uncontrolled bleeding throughout the body, leads to death in nearly all apes and in about 80 percent of infected humans.

There are differing opinions in the scientific community about what sparks the outbreaks and why they appear to be moving westward. Some studies suggest they are spread by insects, bats or mammals, allowing the virus to move from one ape population to another. They are focused on finding the “vector” of transmission to determine how to halt the spread to other core populations.

“Key populations are at risk,” says Carroll. He says one focus of concern is Odzala, a huge park on the edge of Congo, where there is an abundant supply of a certain kind of vegetation that attracts gorillas. The area has a high density of gorillas — 10 or 11 per square kilometer. “If you get a disease here … it could really go through a population with high density like that. It could be disastrous.”

Others scientists believe this virus and others simply exist in the ecosystem, and take hold when ecological conditions are ripe. They note that outbreaks have been seen in the Sudan and Ivory Coast, almost certainly independent of the outbreaks in central and west Africa.

What the experts do agree on is that if the disease continues unchecked, it may take hundreds of years — or become impossible — for ape populations to recover.

Even in the best of conditions, they reproduce slowly compared to most of the animal kingdom. Female gorillas typically don’t begin mating until they are around 10 years old, and rear only one infant about every six to eight years. Male gorillas don’t begin mating until they are about 15.

The scourge of logging, bush meat
But study of Ebola as a threat tends to lead scientists back to problems recognized earlier — devastation of forest habitat the animals need to survive, and poaching of apes for their meat or for body parts that are sold as souvenirs.

The problems are intricately intertwined. Overseas demand for hardwood drives the logging industry to push ever farther into pristine forests, exposing wildlife to hunters.

The loss of habitat is at its worst in Indonesia and Malaysia, which share the forests of Borneo, home to the tree-dwelling orangutan. Unchecked illegal lumbering is depleting the forest by as much as 5 percent a year in Borneo, particularly in Indonesia, where the government has been distracted by political and economic crises since the late 1990s. Baby orangutans are captured and sold as pets or wind up as sideshows — as in Thailand, where the apes are dressed in silk shorts and trained to box each other in a ring.

In Africa and Asia, poverty among villagers and the employees of the lumber companies prompts them to hunt endangered apes to supplement incomes. Roads cut into the forests allow large loads of wild game to be transported from the forests to the cities, and as far away as New York, where illegal game is sold at a premium.

The increasingly close contact between humans and apes spreads disease in both directions — with ease, owing to the similarity of human and ape genetic make-up. Ebola outbreaks in humans have been traced to the handling of infected ape carcasses, while apes sometimes die in large numbers from measles, tuberculosis, scabies or influenza — illnesses contracted from tourists, villagers and wildlife park staff.

“There are a lot of diseases that we should be protecting apes from,” says William Karesh, head of the Field Veterinary Program at the Wildlife Conservation Society.

Vaccines can help prevent some illnesses in animals and people, and Karesh points out that both populations need to be kept healthy to make conservation work. In the end, saving the great apes will also mean making sure that there is a large number of large separate ape populations, each of which is clearly viable. “Then you have to be very aggressive about protecting those gorillas from being infected with diseases, shot by poachers, and that their trees are not cut down by logging companies,” he says.

Ape science and politics
The successful ape-saving strategy clearly relies on a combination of research, enforcement of conservation rules, poverty alleviation and medical research. But how should the costs be divvied up?

Some groups will lobby for funding Ebola vaccine research. Efforts to develop a vaccine are already under way and it may be available in a year or two. Once in hand, scientists and primatologists will face the challenge of administering it to the animals — especially the large and notoriously shy lowland gorilla.

But as evidenced with the bush meat problem, which created an international furor several years ago, the path to a solution can be a long one, while ape populations are quickly diminishing. “The bush meat problem is probably still getting worse,” says Rebecca Kormos, a chimpanzee specialist and research fellow at Conservation International . “People are doing a lot of studies trying to understand it, but there are very few actions on the ground. We’re still at the stage of trying to get our heads around it.”

Karesh says that community-based programs under way by his WCS have helped communities halt the bush meat trade, but it’s slow going. “It takes a lot of trust and a lot of work in a very wide area. And you’re working in a cultural system that doesn’t believe infectious disease exists.”

Nonetheless, this is the answer, he says. “You tell villagers that you can get sick or die if you eat that animal, so don’t pick or shoot. If all they have is two bullets and they are going to go out hunting, they’re going to shoot something they can eat.”

Beyond that, there is a need for both better law enforcement and community-based programs to get locals involved in helping protect the animals. One of the biggest initiatives along these lines was announced by U.S. Secretary of State Colin Powell in 2002. The United States has promised nearly $90 million to build well-managed forestry concessions, sustainable agriculture, and integrated ecotourism programs, as well as to bolster conservation enforcement in six central African nations.

Conservationists say that the GRASP effort could be important for pushing African and Asian governments to adopt conservation plans, and in raising money to fund work.

“The value of it is the talk and the potential collaborative approach,” says one scientist of the GRASP effort. “They can raise awareness with (African and Asian) governments and they’re sanctioned by U.N. so when they visit they will be well-received.” But as with many U.N. efforts, there is anxiety about talk overwhelming action. “As long as it doesn’t consume the money that would otherwise go to conservation,” says the scientist.

At least the apes, with their remarkable similarity to humans, also have charisma on their side.

“In terms of terms of trying to raise funds for wildlife, great apes are sexy species, because they are so similar to people,” says Kormos. “They do move people more than some others, so they can be useful as a flagship species. If you can protect the habitat of great apes, you can protect the habitat of many other species.”

That said, she adds: “It’s still a struggle.”