Voice of America
03-26-07
Science in the News
VOICE ONE:
Research scientists say they have seen chimpanzees making and using
weapons to hunt other animals. The researchers say they saw more than twenty
cases of chimpanzees in Senegal hunting with sharp tools. Their observations
were made between March of two thousand five and last July.
A report on the chimpanzee study was published in Current Biology magazine.
Jill Pruetz of Iowa State University led the researchers. She says it is not
uncommon for chimpanzees to use simple tools. Chimps often use such tools to
open nuts or to find small insects within trees. However, until now, no one has
ever reported seeing the animals using tools for hunting.
VOICE TWO:
Miz Pruetz says the chimps made the tools from tree branches. She says they
removed leaves from the sticks and sharpened the ends with their teeth. Then
the chimps used their tools in a stabbing motion like a person would.
The researchers say they saw chimps stabbing the sharp tools into open holes in
tree trunks. In one case, they saw a West African chimp kill a tree creature called
a bush baby. Chimpanzees eat fruit more often than meat. But they also eat
insects, monkeys and other small mammals for protein.
VOICE ONE:
During their time in Africa, the researchers saw at least ten chimps making sharp
tools for hunting. They witnessed the activity mostly among young female
chimps, ages ten to thirteen years old.
Adult male chimps are considered hunters. But only one adult male was
observed in the tool-assisted hunting. Miz Pruetz notes that the adult males are
stronger and larger than the females. As a result, she says, they are able to kill
smaller animals easily without the use of weapon-like tools. She says the young
females must compete with the stronger males for food.
Chimpanzees are genetically the closest living relatives to human beings.
Because of these ties, the researchers suggest the study may also provide clues
into early humans and their use of tools for hunting.