gimme cap, and a beard. An empiricist by disposition, he speaks quietly, barely moving his mouth, and avoids categorical pronouncements as though they might hurt his teeth. Often he wears a sly smile, suggesting amusement at the wonders of the world and the varied spectacle of human folly. But there was nothing amusing about his mission to the Mambili. He had come to shoot gorillas—not with bullets but with tranquilizer darts. He meant to draw blood samples and test them for antibodies to Ebola virus.
Our destination was a site known as the Moba Bai complex, a group of natural clearings near the east bank of the upper Mambili, not far from the Lossi sanctuary. A bai in Francophone Africa is a marshy meadow, often featuring a salt lick, and surrounded by forest like a secret garden. In addition to Moba Bai, the namesake of this complex, there were three or four others nearby. Gorillas (and other wildlife) frequent such bais, which are waterlogged and sunny, because of the sodium-rich sedges and asters that grow beneath the open sky. We arrived at Moba, coming upstream on the Mambili, in an overloaded dugout pushed by a 40-horse outboard.
The boat carried eleven of us and a formidable pile of gear. We had a gas-powered refrigerator, two liquid-nitrogen freezer tanks (for preserving samples), carefully packaged syringes and needles and vials and instruments, medical gloves, hazmat suits, tents and tarps, rice, fufu, canned tuna, canned peas, several boxes of bad red wine, numerous bottles of water, a couple of folding tables, and seven stackable white plastic chairs. With these tools and luxurious provisions we established a field camp across the river from Moba. Our team included an expert tracker named Prosper Balo, plus other wildlife veterinarians, other forest guides, and a cook. Prosper had worked at Lossi before and during the outbreak. With his guidance, we would prowl the complex of bais, all full of succulent vegetation and previously famed for the dozens of gorillas that came there daily to eat and relax.
Billy Karesh had visited the same area twice previously, before Ebola struck, seeking baseline data on gorilla health. During a 1999 trip, he had seen sixty-two gorillas here in one day. In 2000 he returned to try darting a few. “Every day,” he told me, “every bai had at least a family group.” Not wanting to be too disruptive, he had tranquilized only four animals, weighed them and examined them for obvious diseases (such as yaws, a bacterial skin infection), and taken blood samples. All four apes had tested negative for Ebola antibodies. This time things were different. He wanted blood serum from survivors of the 2002 die-off. So we began, with high expectations. Days passed. As far as we could see, there were no survivors.
Precious few, anyway—not enough to make gorilla-darting (which is always a parlous enterprise, with some risk for both the darter and the dartees) productive of data. Our stakeout at Moba lasted more than a week. Early each morning we crossed the river, walked quietly to one bai or another, concealed ourselves in thick vegetation along the edge, and waited patiently for gorillas to appear. None did. Often we hunkered in the rain. When it was sunny, I read a thick book or dozed on the ground. Karesh stood ready with his air rifle, the darts loaded full of tilletamine and zolazepam, drugs of choice for tranquilizing a gorilla. Or else we hiked through the forest, following closely behind Prosper Balo as he searched for gorilla sign and found none.
On the morning of day 2, along a swampy trail to the bais, we saw leopard tracks, elephant tracks, buffalo tracks, and chimpanzee sign, but no evidence of gorillas. On day 3, with still no gorillas, Karesh said: “I think they’re dead. Ebola went through here.” He figured that only a lucky few, uninfected by the disease or else resistant enough to survive it, remained. Then again, he said, “those are the ones we’re interested in,” because they, if any, might carry antibodies. On day 4, separating from the rest of us, Karesh and Balo managed to locate a single, distraught male gorilla from the sound of his chest beats and screaming barks, and to crawl within ten yards of him in the thick underbrush. Suddenly the animal stood, only his head visible, in front of them. “I could have killed him,” Karesh said later. “Pitted him.” Drilled him between the eyes, that is, but not immobilized him with a