Friday, March 11, 2011
Researchers studied a zoo chimp for 10 years and found he was collecting stones to throw at visitors.
"When the chimp first got to the zoo, he didn't throw many stones. But the few times he did got quite a reaction. And his rate of stone throwing picked up. Researchers swept the chimp’s area and found caches of stones. Then a caretaker hid and watched the chimp collect stones to throw later. Eventually the chimp tapped at concrete structures to break off pieces to throw."
The behavior is different from a chimp using a stick to collect termites to eat - which would be meeting an immediate need. The stone thrower is clearly and calmly planning for future events.