Topic: Chimps Do Craft Tools By Stripping Twigs

[Muero]

Here's an example of chimps crafting spears and hunting!

WASHINGTON (Reuters) - Chimpanzees have been seen using spears to hunt bush babies, U.S. researchers said on Thursday in a study that demonstrates a whole new level of tool use and planning by our closest living relatives.

Perhaps even more intriguing, it was only the females who fashioned and used the wooden spears, Jill Pruetz and Paco Bertolani of Iowa State University reported.

Bertolani saw an adolescent female chimp use a spear to stab a bush baby as it slept in a tree hollow, pull it out and eat it.

Pruetz and Bertolani, now at Cambridge University in Britain, had been watching the Fongoli community of savanna-dwelling chimpanzees in southeastern Senegal.

The chimps apparently had to invent new ways to gather food because they live in an unusual area for their species, the researchers report in the journal Current Biology.

"This is just an innovative way of having to make up for a pretty harsh environment," Pruetz said in a telephone interview. The chimps must come down from trees to gather food and rest in dry caves during the hot season.

"It is similar to what we say about early hominids that lived maybe 6 million years ago and were basically the precursors to humans."

Chimpanzees are genetically the closest living relatives to human beings, sharing more than 98 percent of our DNA. Scientists believe the precursors to chimps and humans split off from a common ancestor about 7 million years ago.

Chimps are known to use tools to crack open nuts and fish for termites. Some birds use tools, as do other animals such as gorillas, orangutans and even naked mole rats.

But the sophisticated use of a tool to hunt with had never been seen.

Pruetz thought it was a fluke when Bertolani saw the adolescent female hunt and kill the bush baby, a tiny nocturnal primate.

But then she saw almost the same thing. "I saw the behavior over the course of 19 days almost daily," she said.

PLANNING AND FORESIGHT

The chimps choose a branch, strip it of leaves and twigs, trim it down to a stable size and then chew the ends to a point. Then they use it to stab into holes where bush babies might be sleeping.

It is not a highly successful method of hunting. They only ever saw one chimpanzee succeed in getting a bush baby once. The apes mostly eat fruit, bark and legumes.

Part of the problem is this group of chimps is shy of humans, and the females, who seem to do most of this type of hunting, are especially wary. "I am willing to bet the females do it even more than we have seen," she said.

Pruetz noted that male chimps never used the spears. She believes the males use their greater strength and size to grab food and kill prey more easily, so the females must come up with other methods.

"That to me was just as intriguing if not even more so," Pruetz said.

The spear-hunting occurred when the group was foraging together, again unchimplike behavior that might produce more competition between males and females, she said.

Maybe females invented weapons for hunting, Pruetz said.

"The observation that individuals hunting with tools include females and immature chimpanzees suggests that we should rethink traditional explanations for the evolution of such behavior in our own lineage," she concluded in her paper.

"The multiple steps taken by Fongoli chimpanzees in making tools to dispatch mammalian prey involve the kind of foresight and intellectual complexity that most likely typified early human relatives."

from http://news.yahoo.com/s/nm/20070222/sc_nm/chimps_hunting_dc;_ylt=Alvvu8KDs3o.9D4EA3K4PasDW7oF

[Mike]

Great post on Steve's blog that deals with this topic.

[skidoo]

Great post on Steve's blog that deals with this topic.

Cool. Nice wrap-up.

Tangentially, I'm curious: Are the implications of crafting stone tools versus wooden tools only interesting from an archeaological/paleontological perspective? It doesn't require any more significant sophistication to work stone, does it? Tool-making is tool-making, right?

[Steven Novella]

The most significant implications are archeological. Stone tools survive in the record, wooden tools do not. And only stone tools that are modified either by use or for use would be recognized as tools. The big question here is whether or not stone tools that have been attributed to humans ancestors may have been made my chimps, or chimp ancestors.

Is it more intellectually sophisticated to modify stone tools than wooden tools? I don't know how to quantify this. I think the techniques for modifying stones are probably more difficult than just stripping branches and bark. Stripping is a behavior apes already have as they use it in some cases to strip leaves for eating. So stripping to modify a tool could be just the application of one behavior to a new purpose. Modifying stones seems more diffcult - you have to strike one stone with a harder stone.  This may have started really simply - splitting a stone to achieve a flat side for smashing, for example. And this may have led to flaking to produce an edge, which requires some technique.

So my sense is that stone tool making is a bit more sophisticated than stick tools, but the most basic modifications of stones are probably just one step up. Of course, stone tool use became very sophisticated among our ancestors, leading up to the homo sapiens stone tool kit that was highly developed - including artistic pieces that would not have been functional.

[wallet55]

I agree with Dr. Novella's original misdirection. The article in hand did not describe "crafting" tools.

That said, is it not grand that for a game with no monetary value, so many can be so engrossed in such a distinction??

[ChocolateCheepnis]

the game is simple...the language was simple, and the response is correct.  within the confines of the game, the phrase "crafting stone tools" is precise and clear, and the question of capability or quantifiable intelligence is moot because these issues were not in any way connected to the game.

is there a recorded logical fallacy that deals with attention to detail?  seems to be bourne of a false premise and then the subsequent maturity into correlation implying causation.