Contrary to the conventional wisdom about the male of the species acting as hunter-gatherers, female chimpanzees in Senegal have been found not just hunting other primates for food but also fashioning the tools to do the killing. Use of tools by large apes, particularly chimpanzees, has been observed before, usually for poking anthills with slender twigs. In those cases, the chimps choose a tool - selecting a thin twig over a thicker branch. But this is the first time that they have been observed making a tool to kill a prey.
Chimpanzees in Senegal are regularly making and using spears to hunt other primates -- without human assistance -- according to research led by an Iowa State University anthropologist. That study, funded by the National Geographic Society, is the first to report habitual tool use by non-humans while hunting other vertebrates.
ISU Assistant Professor of Anthropology Jill Pruetz and Paco Bertolani -- a graduate student with the Leverhulme Centre for Human Evolutionary Studies, Department of Biological Anthropology at the University of Cambridge in England -- documented 22 cases of the chimps fashioning tools to use in hunting smaller primates in cavities of hollow branches or tree trunks. They made the discovery at their research site in Fongoli, Senegal between March 2005 and July 2006.
Chimpanzees forcibly jabbed tools into hollow trunks or branches multiple times and smelled and/or licked them upon extraction. Only two of the 22 reported cases were seen as playful -- in the case of an infant male -- or exploratory in nature. In all other cases, chimps were judged by the researchers to use such force in inserting the tool that prey within the tree could have been injured. They witnessed just one case in which a chimpanzee extracted a bushbaby -- a smaller primate -- through use of the spear.
Females lead tool-assisted hunting
Despite the fact that hunting is predominantly an adult male chimpanzee activity, only one adult male (of 11 males in the community) was observed in the tool-assisted hunting. The reported incidents included one adult female, one adult male, three adolescent females, two adolescent males, one juvenile female, one juvenile male, and one infant male.
"In the chimp literature, there is a lot of discussion about hunting by adult males, because basically, they're the only ones that do it -- and they don't use tools," said Pruetz. "Females are rarely involved. And so this was just kind of astounding on a number of different levels. It's not only chimps hunting with tools, but females -- and the ones who hunted the most with them were adolescent females.
The rest of the fascinating story here.
The implications for the evolution of human behavior is quite astounding, from these observations. So, essentially, instead of early 'man' creating tools for use, it may well have been early 'woman' who learnt to use objects as tools and passed on the information on how to use them to her offspring.
Posted by: Sujatha | February 26, 2007 at 03:15 PM
Doesn't sound too far fetched to me. We women are always having to improvise. The men go out and buy Cuisinart! :-)
No, but seriously, I would guess that males and females probably are both good at making tools when necessary. But as this article suggests, if the mother is the innovator, the offspring (both male and female) are also likely to be inventive. Which is why the older male chimpanzees in this group are the most inept in using tools. I would infer from this that the best male artisans and artists in primitive societies probably grew up around industrious and innovative mothers. "The hand that rocks the cradle... etc."
Posted by: Ruchira Paul | February 26, 2007 at 03:48 PM