Tuesday, August 4, 2009

Wild Spider Monkeys use Tools to Scratch Their Body

A Geoffroy's Spider Monkey hanging on the branch. Photo from Primate Info Net.

Wild Geoffroy's Spider Monkeys (Ateles geoffroyi) or Black-handed Spider Monkeys had been documented using tools to scratch themselves, according to a new publication "Tool use in wild spider monkeys (Ateles geoffroyi)". Important to note that spider monkeys do not have thumbs, only four fingers (picture below) so tool manipulation is rather limited but nonetheless a rather interesting find.

The hand of a Geoffroy's Spider Monkey. Note that they do not have a thumb and only four fingers. Photo from Wikipedia.

Published in the latest issue of Primates, authors Stacy Lindshield and Michelle Rodrigues collected their data from wild spider monkeys at El Zota Biological Field Station in northeastern Costa Rica. There were three documented instances where these spider monkeys used tools to scratch themselves.

The first to scratch was an adult female. Holding a small, leafy branch in her hand, she scratched her chest and abdominal regions.
The second, another adult female, used a detached stick lacking side branches and leaves to scratch her left side. She chewed the tool tip between bouts.
The third individual, a juvenile female, first chewed the distal tip of a stick before scratching the underside of her tail and her genital region.

Seems that this publication coincide with the call for an inter-disciplinary field that seek to examine primate tool use in a long term, evolutionary context. Julio Mercader, archaeologist from University of Calgary, said "We used to think that culture and, above anything else, technology was the exclusive domain of humans, but this is not the case."
Read the full article on Discovery: Spider Monkeys Invent Medicated Body Scratcher.


Zachary Cofran said...

"We used to think that culture...was the exclusive domain of humans, but this is not the case."

Well, depends on how you define culture, of course. So it's all circular. But I think that there's something inherently 'special' about human culture. After all, we humans are so reliant upon our culture--I suppose most simply technologies and traditions--that we rely on it for survival more than any animals do on their alleged 'cultures.' And if you count using a stick for something other than being a stick as "technology," then technology is rampant in the animal kingdom.

While I think it's interesting to see animals doing things that were erstwhile considered "cultural" or "uniquely human," I don't think that there is anything wrong with redefining our behaviors such that they are always exclusively human. After all, that's part of what Anthropology is all about.

Raymond Vagell said...

You're right, Zacharoo. Culture has a lot of meanings and in primatology it is totally different from the "culture" that's defined in the other anthropology discipline.

In primatology, culture is defined as a learned behavior that can be observed and passed down from one individual to another. There are, of course, a much descriptive way of interpreting and classifying culture but I'm sure you get the gist of it.

Primate culture and tool use is not only important to show how intelligent and complex these animals are, they also give us a glimpse as to how early hominins invented, use and perfected tool use and how it was passed down from one individual to another.