From Daily Telegraph (
http://portal.telegraph.co.uk/news/m...7/ixworld.html):
"We could hear them in the trees, about 20 feet away," she said. "My tracker made a sound of an injured duiker [antelope] and four came rushing through the brush towards me.
"If this had been a bluff charge, they would have been screaming to intimidate us. These guys were quiet. And they were huge. They were coming in for the kill. I was directly in front of them, and as soon as they saw my face, they stopped and disappeared."
Discovery Planet changed the whole encounter that Karl Ammann had with the gorillas - they thought they were going after a wounded antilope and when they instead found a human they split. This species is definitely an extraordinary find, but it's intelligence doesn't need to be oversensationalized.