Santino the chimp's stone-throwing tactical war on zoo visitors
A chimp whose behavior gained attention of researchers and earned him notoriety among zoo visitors is back in the news. Santino recently demonstrated what seems evidence of a nonhuman species deploying premeditated tactics in aggressive confrontation.
Santino the chimp is a resident of the Furuvik Zoo, in Gavle, Sweden. He methodically gathers stones in the mornings, piles them up in anticipation of arrival of zoo visitors whom he pelts apparently in protest at their gawking behavior. Santino appears offended at being stared at and throws stones to urge visitors to move on.
reports zookeepers discovered that Santino spent considerable time when the zoo was closed to visitors collecting stones and dragging them across the protective moat that surrounded his enclosure to where he arranges them in piles in anticipation of arrival of zoo visitors.
After zoo keepers removed the stones, Santino was observed trying to fashion new missiles by tapping concrete floor with his fist and releasing chunks of concrete he then fashioned into discs suitable for throwing. According to cognitive scientist Mathias Osvath, "Forward planning like this is supposed to be uniquely human; it implies a consciousness that is very special, that you can close your eyes you can see this inner world. Many apes throw objects, but the novelty with Santino is that he makes caches of these missiles while he is fully calm and only throws them much later on." Osvath concluded: "We are not alone in the world within. There are other creatures who have this special consciousness that is said to be uniquely human."
According The Guardian
, interviews with zoo keepers showed that Santino only gathered rocks and made concrete missiles when the zoo was closed. He gave up the behaviour when the zoo was shut over the winter.
But others scientists expressed skepticism of the belief that the chimp was planning ahead for an emotional outburst. They argued that the chimp might only be displaying a form of behavior known as associative learning, that is, Santino is merely mechanically repeating previously learned responses to zoo visitors.
reports that skeptics pointed out that Santino's behaviour is not altogether unusual among dominant male chimpanzees who throw sticks, rocks, branches and even feces at zoo visitors.
But even more recently, Santino came once again to the center of attention with new claims that he has developed new cognitive skills in his self-declared war on mankind by deliberately concealing stones so that he can get closer to his targets for a better aim. Research observers of Santino's behavior claim he is displaying ability to think and plan ahead.
But the latest claims have raised new controversy over whether scientists are interpreting Santino's behavior correctly. A psychologist at the University of Toronto, Sara Shettleworth, had argued in a 2010 article titled
“Clever animals and killjoy explanations in comparative psychology,” that there is no evidence that Santino began collecting stones with the purpose of pelting zoo visitors. She argued that he might have started throwing stones at the visitors incidentally.
In the most recent study published in PLoS ONE
, primatologist Mathias Osvath of Lund University in Sweden and Elin Karvonen, report new observations of Santino's behavior. According to Science Now
, the scientists report they have observed a new pattern in Santino's stone-throwing behaviour:
"As a zoo guide led visitors toward Santino’s island compound, the chimpanzee began to engage in a typical dominance display: screeching, standing on two feet, and carrying a stone in his hand. The guide and the visitors retreated before Santino began hurling the stones, and then advanced again for a total of three approaches. When the people returned about 3 hours later, Santino advanced toward them, holding two stones, but he did not act aggressively, even picking up an apple from the water surrounding the island and nonchalantly munching on it. But when Santino got within close range, he suddenly threw one of the stones."
An obvious interpretation of Santino's behavior on this occasion is that he is engaging in premeditated action. Science Now
reports that the next day:
"Santino was then observed pulling a heap of hay from inside his enclosure and placing it on the island close to where the visitors approached. He put several stones under the hay and waited until the group returned about an hour later. Then, without performing a dominance display, Santino pulled a stone from under the hay and threw it. Later, he pulled a stone that he had apparently hidden behind a log and tried to hit the visitors with that, as well."
The researchers observed the chimp's behavior over a course of time and recovered stones the chimp had hidden under hay, logs and other strategic spots. The scientists recovered 35 projectiles Santino had apparently deliberately concealed: 15 under hay, 18 behind logs and two behind a rock structure in his enclosure. The researchers concluded that the chimp was deliberately engaging in deceptive behavior, concealing the stones to allow him get within range before striking.
Equally important, according to Wired.com
, was the fact that Santino's behavior may be described as innovative because he had previously not behaved that way. His new pattern of behavior was taken as evidence that the animal had planned his actions ahead of arrival of zoo visitors. By hiding stones and then simulating nonchalance by munching casually at an apple, Santino was deliberately trying to deceive human observers into thinking that his intentions were peaceful.
Osvath and Karvonen asserted: “No matter what mechanisms lie behind the behavior, Santino is engaging in planning for the future, and that is not trivial.”
But again, Shetttleworth, chief of the "killjoy" researchers raises objections. Even though she admits that the latest study is "provocative" she queries: “Did he bring the first hay pile into the arena with the intent of using it to hide projectiles? We cannot know."
According to Shettleworth, the authors should have tried other tests, such as putting a hay pile in his enclosure themselves and “seeing if the animal still persisted in carrying hay,” or “putting the hay piles in unfavorable locations for throwing.”
Another cognitive psychologist at the University of Queensland, Brisbane, Australia, agrees with Shettleworth's reservations. While admitting that the observations do indeed suggest "extraordinary capacities" of “planning and premeditated deception” he insists that we cannot yet rule out "leaner interpretations" without further "experimental study.”