WASHINGTON — It’s a little disappointing, but perhaps not surprising, that a newly documented example of planning ahead by our closest nonhuman relative involves stockpiling weapons.
In a scientific paper published Monday, a primatologist describes an adult male chimpanzee in a Swedish zoo often collects stones before opening time so he can have them ready later on when visitors arrive and he becomes agitated.
On some days, the 30-year-old chimp has barraged visitors with up to 20 projectiles thrown in rapid succession, always thrown underhand. Several times he has hit spectators standing about 30 feet across a water-filled moat.
The behavior, witnessed dozens of times, has made the chimp something of a local celebrity.
The animal’s preparations include not only stockpiling stones he finds, but more recently also fashioning projectiles from pieces of concrete that have broken off artificial rocks in his habitat.
“Many animals plan. But this is planning for a future psychological state. That is what is so advanced,” said Mathias Osvath, the director of the primate research station at Lund University and author of the paper in the journal Current Biology.
Others have also observed great apes planning, both in the wild and in captivity. Some birds in the corvid family, which includes jays and ravens, also plan for future contingencies. In general, though, planning by animals is thought to occur only when the payoff is immediate and more or less certain.
“People always assume that animals live in the present. This seems to indicate that they don’t live entirely in the present,” said Frans de Waal, a primatologist at Emory University in Atlanta, who was not involved in the research.
The chimpanzee, Santino, was born in a zoo in Munich in 1978 but has lived all but five years of his life at Furuvik Zoo, about 60 miles north of Stockholm. He began throwing stones at age 16 when he became the sole — and therefore dominant — male in a group that included about a half-dozen females.
The throwing behavior is part of a normal display of dominance and territorial protection by male chimpanzees, and occasionally involves throwing feces. Osvath doesn’t think Santino is particularly smart or aggressive.
“I don’t think he is unusual in any way,” he said. “If anything, chimpanzees in the wild would plan more, I suspect.”
