Ron Pintier was flying light and low above the northern wilds of the Democratic Republic of Congo when he saw a dark shape racing between two patches of tropical forest. "It was huge," says Pontier, a missionary pilot. "It was black. The skin was kind of bouncing up and down on it." From its bulk and color, Pontier thought it was a buffalo until he circled down for another look. "I saw it again just before it went into the forest," he says. "It was an ape--and a big one." Not buffalo size, but big.
What Pontier saw was a piece of a primatological puzzle, another splinter of anecdotal evidence for a mysterious ape with characteristics of gorillas and chimpanzees, an animal that has scientists in a furious debate over what it might be.
Bili lies in Congo's far north, about 120 miles east of the Ebola River, where deep tropical forest breaks up into patches of savanna. Civil war and neglect have left the region nearly untouched by man. Overgrown dirt roads with bridges of rough-hewn logs string together thatched-roofed villages. Nearly all freight is carried in by bicycle. Locals hunt with homemade shotguns and crossbows seemingly modeled on 16th century Portuguese design. "This area is the last part of Africa where there are still wild animals," says Pontier, who grew up in the region. "It's not a game park. It's not a reserve. The animals are really wild."
When Karl Ammann, a Swiss photographer crusading against the killing of wild animals for meat, first visited the region in 1996, he was looking for gorillas, hoping that the great apes still roamed its jungles. What he found surprised him. Locals had two names for the apes in their forests: the tree beaters, which stayed safe in the branches, and the lion killers, bigger, darker and so strong that they were unaffected by the poison arrows used by local hunters.
Ammann discovered a strange skull with the dimensions of a chimpanzee's but with an odd, prominent crest like a gorilla's. Motion-detecting cameras in the forest caught what looked like immense chimpanzees, and a photograph purchased from poachers showed hunters posing with an animal estimated to be twice the size of an ordinary chimp. Ammann measured a fecal dropping three times as big as chimp dung and footprints as large as or larger than a gorilla's.
Most intriguing were the gorilla-like ground nests found in the riverine swamps. Chimps normally make their nests in the high safety of trees. Why would they build their beds of branches and shoots on the ground? And why here, of all places? At night Cleve Hicks, 32, a Ph.D. student who observes the animals, regularly hears the laughs of hyenas and the guttural cries of leopards. Recently, his trackers filmed the footprints of a lion crossing a river. But the apes here--at least some of them--pulled together branches and shoots to make a bed on the ground. "We know [the apes] are a perfect target for leopards," says Hicks. "So how can they get away with that?"