Yes, we know they're cute, and, yes, we knew they were smart. But new research shows African chimpanzees to be smarter than anyone thought.
It has long been known that they use sticks as crude tools — but now there is proof that they switch tools, something that had never been seen before. Scientists say that is a remarkably advanced concept for a primate.
"An analogy is, say, a human goes into the garage and picks, among a set of screwdrivers, a flathead instead of a Phillips head," said Augustin Fuentes, an associate professor of anthropology at Notre Dame. "This shows us that chimpanzees are incredibly intelligent, incredibly cognizant of their surroundings, and do very complex things."
With sponsorship from the National Geographic Society and New York's Wildlife Conservation Society, a team of researchers went to the Goualougo Triangle, a remote forest in the Republic of Congo.
There, they set up remote-controlled video cameras and left them running for six months.
The chimps learned to ignore them — and went on to the much more interesting business of catching termites for lunch.
"I can't even tell you the surprise that we had [when viewing] that first video clip," said Crickette Sanz, the anthropologist from Washington University who led the expedition. "They [the chimps] arrive at these nests and they are carrying their tool sets with them. So they know the location that they're going to. And they're prepared. They've gathered the appropriate materials. And they arrive there ready to extract the termites from that underground nest or that elevated nest."
Sanz and her partner, David Morgan, have been camping in the Congolese forest to study the chimpanzees.
"To see it — the chimps using tools — and then to see it so clearly, it was a window into their lives that we had thought an awful lot about," Morgan said by satellite telephone. "But to be able to see it and to describe it and understand it a little bit better was amazing."
Sanz, Morgan and a third researcher, Steve Gulick, have just reported their findings in The American Naturalist, an academic journal.
Time and again, they say, the video, from six different locations in the forest, would show much the same thing: a chimpanzee using a sturdy stick to make a hole in a termite nest.
That done, the chimps would switch to a much thinner twig. They would flatten out the end with their teeth and use it to scoop out termites to eat.
The chimps would sometimes leave their stick tools in place to share with other chimps from their group. Other times, said Sanz, they would take the tools with them, apparently to reuse them elsewhere.
Why does it matter if a chimp changes tools? Fuentes, the Notre Dame anthropologist who approved the publication of the study, says that until now, we've only known of one other species smart enough to do such a thing: human beings.
"We're not going to see chimpanzees flying airplanes; we're not going to see chimpanzees opening bank branches," said Fuentes with a smile. "We are, however, going to see chimpanzees doing the kinds of stuff we think our ancestors did."
So don't worry, say the scientists, we humans are still smarter; for one thing, the chimps depend on us to protect their forests.
But the line between human and animal, says Fuentes, just got a little murkier.