Big dudes, apparently.
CC
-------------------------------
Amman got hold of a photograph, taken by bush meat hunters, which appeared to show a huge chimpanzee. He found droppings several times larger than chimp dung and footprints bigger than a gorilla's.
He recounted what locals had told him about the animals. "Gorilla males will always charge when they encounter a hunter, and if you were charged by a gorilla you would never forget it, but there were no stories like that," Amman says.
Instead, these apes would come face-to-face with their human cousins, stare intently, then slide away quietly. No aggression, yet no fear either.
Then, in 2004, Shelly Williams, a primatologist affiliated to the Jane Goodall Institute, revealed the first recorded close encounter by a scientist with these creatures, in the New Scientist.
"We could hear them in the trees, about 20ft away – and four suddenly came rushing through the bush towards me," she wrote. "If this had been a bluff charge they would have been screaming to intimidate us.
"These guys were quiet, and they were huge." At first, she feared they were 'coming in for the kill', but perhaps sensing an unknown danger, they thought better of it and retreated.
She said the apes had a flat face, with a wide muzzle and – most strikingly – grey fur all over their face and bodies. It seems that Crichton's fictional grey killer apes had been found.
The report was met with some scepticism, but most scientists were convinced that something new had been discovered.
Excerpt taken from: link