Tools and primates: Opportunity is the mother of invention
When food is scarce, tool use among primates does not increase. This finding leads researchers to suggest that the force behind tool use is ecological opportunity, and that the environment shapes the development of culture. Whether you're a human being or an orangutan, tools can be a big help in getting what you need to survive.
However, a review of current research into the use of toolsby non-human primates suggests that ecological opportunity, rather than necessity, is the main driver behind primates such as chimpanzees picking up a stone to crack open nuts. An opinion piece by Dr Kathelijne Koops of the University of Cambridge and others, published today (12 November 2014) in Biology Letters, challenges the assumption that necessity is the mother of invention. She and her colleagues argue that research into tool use by primates should look at the opportunities for tool use provided by the local environment.
Koops and colleagues reviewed studies on tool use among the three habitual tool-using primates, chimpanzees, orangutans and bearded capuchins. Chimpanzees use a variety of tools in a range of contexts, including stones to crack open nuts, and sticks to harvest aggressive army ants. Orangutans also use stick tools to prey on insects, as well as to extract seeds from fruits. Bearded capuchin monkeys living in savannah-like environments also use a variety of tools, including stones to crack open nuts and sticks to dig for tubers.
The researchers' review of the published literature, including their own studies, revealed that, against expectations, tool use did not increase in times when food was scarce. Instead, tool use appears to be determined by ecological opportunity with calorie-rich but hard-to-reach foodstuffs, such as nuts and honey, appearing to act as an incentive for an ingenious use of materials.