Monday, January 23, 2012

The Impact of Ebola in the Forest


In three essays in Natural Acts: A Sidelong View of Science and Nature, David Quammen profiles the work of Mike Fay who did a 2,000 mile walking "megatransect," with pygymy porters, through the wildest and most inhospitable parts of the Central African Republic and Congo, ending up on the coast of Gabon after 18 months of walking through poacher-infested forests and leech-infested swamps.

Quammen writes of what they found -- and did not find -- in the Minkébé National Park in Gabon:

They found spectacular zones of forest and swamp, stunning inselbergs, networks of streams, all rich with species and virtually untouched by human presence. They also found — as Mike Fay has been finding — a nearly total absence of gorillas and chimpanzees. It wasn’t always so. In 1984 a paper appeared in the American Journal of Primatology, by Caroline Tutin and Michel Fernandez, in which the authors described their census of gorilla and chimpanzee populations throughout Gabon. Using a combination of field transects, habitat analysis, and cautious extrapolation, Tutin and Fernandez estimated that at least 4,171 gorillas lived within the Minkébé sector, representing a modest but significant population density. Something seems to have happened to those apes between 1984 and now. It may have happened abruptly in the mid-1990s, when three Ebola epidemics burned through villages and gold camps at the Minkébé periphery, killing dozens of humans. One of those outbreaks occurred in early 1996 at a village called Mayibout 2, on the upper Ivindo River. It began with a chimpanzee carcass, found dead in the forest and brought to the village as food. Eighteen people who helped with the skinning, the butchering, and the handling of the chimp flesh became sick. Suffering variously from fever, headache, and bloody diarrhea, they were evacuated downriver to the Makokou hospital. Four of them died quickly. A fifth escaped from the hospital, went back to Mayibout 2, and died there. That victim was buried in the traditional way—ceremonies were performed, and no special precautions were taken against infection.

By early March, thirty-one people had fallen ill, of whom twenty-one died, for a mortality rate of almost 68 percent. Then it was over, as abruptly as it started. Around the same time, according to later accounts, dead gorillas were seen in the forest.

... [Fay] spends hours in his tent, collating the latest harvest of data on his laptop. Within the past fourteen days, he informs me, we have stepped across 997 piles of elephant dung and not a single dung pile from a gorilla. We have heard zero gorilla chest-beat displays. We have seen zero sprigs of Marantaceae chewed by gorilla teeth and discarded. These are numbers representing as good a measure as now exists of the mystery of Minkébé.

See National Geographic's interactive web site for more information.
.

No comments: