A capuchin monkey gently places a palm nut on a log. T e nut is about the size of its fist. T e monkey reaches for a large rock, about the size of its head. Heaving the rock above its head, the monkey brings the rock down on top of the nut. Whack. T e nut bounces off the log and rolls away. Patiently, the monkey puts the nut back
on the log and liſt s the rock. Whack. Whack. Whack. Whack. Over and over again, the monkey strikes the nut. At last, the nut cracks open. T e monkey grabs it and scampers up the nearest tree to eat it. T e monkey turned a simple rock into a tool to crack the nut.
A Moment of Discovery A tool is an object that can be used to accomplish a task. Before the 1960’s, most scientists thought that only humans used tools. T en, National Geographic explorer Jane Goodall changed the way people think about animals. In 1960, Goodall was studying wild
chimpanzees in Africa. One day, she observed a chimp poking pieces of grass into a termite mound. T en the chimp raised the grass to its lips. At first, she wasn’t sure what the chimp was doing. To unravel the mystery, she poked a piece of grass into a termite mound to see what would happen. T e termites inside the mound bit into the grass with their jaws. T ey clung to the grass as she pulled it from the mound. T e chimp had been using the grass as a tool to “fish” for termites! Soon aſt er, Goodall saw chimps picking up
leafy twigs. T ey stripped off the leaves and used the stems to hunt for insects. T e chimps changing a leafy twig into a tool was a major discovery. Before this, scientists didn’t think animals could make tools. T ey thought that the ability to make and use tools was a skill that separated humans from other animals. Goodall discovered that chimps make tools
from twigs, branches, leaves, and rocks. T e chimps use these tools for eating, drinking, and cleaning themselves. Sometimes they even use tools as weapons.
4 NATIONAL GEOGRAPHIC EXPLORER
A Matter of Survival Scientists have come to realize that making and using tools is a behavioral adaptation. T ese are traits, or features of an animal that help it to survive in its environment. Some tool use is learned, but some of it is inherited. T at means an animal is born knowing what to do. For example, many birds are born
knowing how to make and use tools. T e Galapagos woodpecker finch is a good example. T is finch eats small, wood-boring insects and grubs. Yet its beak can’t always squeeze into the small spaces where these insects live. Also, the finch doesn’t have a long tongue, like a true woodpecker. So, it needs a little help reaching its food. When the finch finds food,
it flies to a cactus, breaks off a spine, and returns to spear its prey. If there are no cacti around, the finch might break off a twig from a bush or tree. If the twig isn’t sharp enough, the finch will trim it with its beak. T e Egyptian vulture uses tools,
too, but nothing so delicate as a cactus spine. One of this bird’s favorite foods is ostrich eggs. T e giant eggshell can be difficult to break, though. T e vulture uses a tool
to break the eggshell. It picks up a stone with its beak. T en, it snaps its head forward to hurl the stone on the egg. Oſt en, it takes more than one try to crack the egg!
A rock makes a good tool for an Egyptian vulture to crack open an egg.
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