Which primates use tools

So, too, with the capuchins of Serra da Capivara, which still today smash open the tough husks of cashews with rounded quartzite cobbles, which range in size from about an inch wide to roughly the size of a human fist. For centuries, locals and visitors to Brazil had told stories of tool-using capuchins, and for decades, scientists had known that capuchins could wield tools in captivity and in laboratory tests.

About a decade ago, the research team behind the new study set out to excavate sites in Serra da Capivara, in an attempt to see how far back the tool use went.

After four phases of excavation, the team had dug down through about 3, years of sediments, based on the radiocarbon dating of charcoal in the soil layers—and they were still finding telltale capuchin stone tools. The researchers think that, at the time, capuchins were eating smaller foods.

Ever since, the Serra da Capivara capuchins have wielded far larger stones, implying that they were going after harder foods. Perhaps different groups of capuchins, each with their own distinct tastes, lived in this patch of Serra da Capivara over the millennia.

That way, researchers can more readily ascribe stone tools at different sites to their wielders—and understand the evolutionary underpinnings of tool use across primates. After all, not all groups of capuchins use stone tools—so why do the ones at Serra da Capivara and at sites in Panama? All rights reserved. Share Tweet Email. Read This Next Wild parakeets have taken a liking to London. Animals Wild Cities Wild parakeets have taken a liking to London Love them or hate them, there's no denying their growing numbers have added an explosion of color to the city's streets.

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My colleagues and I carried out an experimental field study that focused on understanding how these monkeys prepare to use their tools. Just as a person might move her hands around a box to decide how best to lift it, monkeys at this site feel their way through tool use. First, we placed unfamiliar stones and palm nuts around naturally-occurring wood or stone anvils. Since the monkeys frequently use stones to crack open these tough nuts on the anvils, it was only a matter of time before they tried out the experimental stones.

We filmed slow-motion videos of 12 monkeys cracking nuts to understand how monkeys adjust to using an unfamiliar tool. The idea, stemming from perception-action theory , is that monkeys may obtain helpful information about the tool, like how heavy it is, and where they can hold it securely, by manipulating it before they use it. Like testing a hammer with a few light taps before you use it, this information may then help the monkeys to strike the nut forcefully and accurately.

Back in the U. The videos showed that for nut-cracking, monkeys grasp the sides of a stone, lift it to shoulder height, quickly move its hands to the top of the stone, then bring it down on the nut. Wild chimp language translated. This video can not be played To play this video you need to enable JavaScript in your browser. Critically endangered chimpanzees in the Ivory Coast craft extra-absorbent drinking sticks, remote cameras reveal.

Image source, Kathelijine Koops. Related Topics. Animals Environment Ivory Coast.