BioEd Online

Africa's chimpanzees are animals on the run from killers. Despite our wonderment at their prodigious social skills, and our appreciation of the close evolutionary kinship our two species share, chimpanzees in their natural habitat bear the misfortune of living cheek by jowl with humans whose own interests are not conducive to the apes' survival.

The African jungle that chimpanzees call home is being destroyed. As swathes of trees are cut down by loggers and prospective farmers, roads are driven deep into once impenetrable forest. And this encroachment brings with it the other main problem for chimpanzees: bushmeat hunters.

Common chimpanzees (Pan troglodytes) are thought to have once numbered in the millions, living in a band across West and Central Africa that includes 25 present-day countries. Today, only 10 of those countries retain a wild chimp population of more than 1,000, and four of them have lost their chimps entirely. Even optimistic estimates put numbers at no more than 200,000.

Things are even worse for common chimps' diminutive relatives, bonobo or 'pygmy' chimpanzees (P. paniscus). Some estimates put their total population at less than 6,000. Both species are increasingly being backed into ever-dwindling corners of jungle (see a map of their habitat destruction here). Bonobos are now found only in an area the size of Great Britain within the Democratic Republic of Congo.

Cash strapped

The United Nations (UN) estimates that at least US $25 million is needed to save the world's great apes, which include Africa's chimpanzees and gorillas as well as orang utans in South-east Asia. By 2003, the US Fish and Wildlife Service had raised some $4.25 million for great ape conservation across the world, but this still falls far short of what's needed.

Klaus Toepfer, executive director of the UN Environment Programme, has described the problem in stark terms: “The clock is standing at one minute to midnight for the great apes, animals that share more than 96 of their DNA with humans. If we lose any great ape species we will be destroying a bridge to our own origins, and with it part of our own humanity.”

Christophe Boesch is working to stop that loss. As president of the Wild Chimpanzee Foundation, based at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, he has spent more than 20 years studying the chimps in the Ivory Coast's Taï National Park, and has no illusions about the apes' plight.

“Things are bad for great apes because they have a long generation time and a slow reproductive rate,” he explains. “A female chimp has a baby only every five years, so it's more difficult for numbers to recover after they drop.”

Even estimating the numbers themselves is a tricky prospect, he says. Wild chimps live in dense forest and shy away from humans, so their populations have to be reckoned by counting nests or droppings. “We can't say for sure how many there are, but we know for certain it's dropping.”

Fenced in

The best hope for chimps is to ringfence them in national parks such as Taï, something that has been done far more successfully in West Africa than in the centre of the continent. Some 60 of west African chimps now live in protected areas, but in Central Africa, governments are lagging behind. Add to that the fact that these regions contain more pristine forest, which is enticing to loggers, and the situation looks grim.

Logging exacerbates the problem of bushmeat hunting because road-building brings humans into close quarters with previously remote chimp groups, Boesch says. “People poach around where they live, so a large enough area can be protected by the mere effect of size,” he explains. “The problem is loggers: they make these roads and often they are poaching to feed their workers.”

As if that's not enough, chimps are threatened by a new menace, one that conservation groups do not have great expertise in dealing with. In some areas of Central Africa, 90 of chimpanzee deaths are attributed to the Ebola virus. The problem is compounded by the fact that the disease represents a genuine health risk to humans who encounter these apes, although that should also be an incentive for people to work to stamp out the disease among their evolutionary cousins.

Overall, the situation looks grim, Boesch admits. But there are steps that concerned people can take, even from the relative comfort of the developed world. “We need to ensure that consumers buy wood from logging companies that have been caring and followed the rules,” he says. That means only logging from designated areas, and having a zero-tolerance approach to bushmeat hunting.

Local know-how

The attitude of local villagers at the Taï National Park is also greatly encouraging, Boesch says. He recalls that locals frequently describe the chimpanzees as 'human beings', and have a wide array of legends that illustrates the high esteem in which they hold the animals.

“They told us: 'Chimpanzees chase and kill red colobus monkeys not in order to eat them, but to use their fur as a backpack,” Boesch says, a story that attributes the animals with a high level of intelligence and resourcefulness.

Such tales are most likely story rather than fact, but they should nonetheless offer hope for conservationists. Boesch says that the villagers' obvious respect for the animals meant that they were valuable in helping Boesch and his small research team get close to the chimpanzees in order to study their social behaviour.

Unfortunately, bringing these apes back from the brink will take more than grassroots enthusiasm, but Boesch hopes that, with enough political will, the situation can be turned around.

Experts plan to meet in Kinshasa, Democratic Republic of the Congo from 5-9 September to discuss what can be done. The UN's Great Apes Survival Project (GRASP) has done some of the modelling studies on great ape decline, and is trying to coordinate efforts for their conservation.

But it won't be easy. “There are so many interests, so many parties involved,” says Boesch. “I'm afraid there will still be a lot of chimpanzees dying before we can revert the trend.”