The story is bouncing all over the wires today after it broke at the academic journal, Current Biology, this morning.
Apparently the 31-year-old alpha male even made his own makeshift projectiles — pieces of concrete he'd managed to dislodge from boulders in his enclosure. Sneaky, sneaky.
Anecdotal observations have been reported off and on from laboratory studies that have created situations that elicit evidence of planning in nonhuman primates, but so far, this is the only report I know of a chimp spontaneously, and unambiguously, planning an activity. Chimps in the wild have been known to hurl objects — mostly branches — during dominance displays but they've never been observed piling up weapons before such displays. Perhaps the materials are so plentiful they don't have to.
In any case, this observation "implies that they [chimps] have a highly developed consciousness, including lifelike mental simulations of potential events," says the lead author of the study, Mathias Osvath of Sweden's Lund University.
Another primatologist, Josep Call, co-author of the best reference book on primate cognition, cautions against over-generalizing the observation. "It could be that he is a genius, only more research will tell," Call said. Not all chimpanzees plan ahead.
The AP version of the story** says that no visitors were actually harmed — no surprise there given that chimps actually have horrible aim.** And darn it if they didn't mispell Josep Call's name when they quoted him! Grrrr. They think he's Joseph.