Kea Show Humanlike Ability to Make Predictions
Whether it’s calculating your risk of catching coronavirus or gauging the chance of rain on your upcoming beach vacation, you use a mix of statistical, physical, and social information to make a decision, Virginia Morell writes for academic journal Science. So do New Zealand’s kea, scientists report. It’s the first time this cognitive ability has been demonstrated outside of apes, and it may have implications for understanding how intelligence evolved.
“It’s a neat study,” says Karl Berg, an ornithologist and parrot expert at the University of Texas Rio Grande Valley, Brownsville, who was not involved with this research.
Keas already had a reputation in New Zealand – and it wasn’t a great one, Morell writes. The olive-brown, crow-size birds can wield their curved beaks like knives – and did so on early settlers’ sheep, slicing through wool and muscle to reach the fat along their spines. These days, they’re notorious for slashing through backpacks for food and ripping windshield wipers off cars.
To see whether keas’ intelligence extended beyond being mischievous, Amalia Bastos, a doctoral candidate in comparative psychology at the University of Auckland, and colleagues turned to six captive keas at a wildlife reserve near Christchurch. The researchers taught the birds that a black token always led to a tasty food pellet, whereas an orange one never did. When the scientists placed two transparent jars containing a mix of tokens next to the keas and removed a token with a closed hand, the birds were more likely to pick hands dipped into jars that contained more black than orange tokens, even if the ratio was as close as 63 to 57.
That experiment combined with other tests “provide conclusive evidence” that keas are capable of “true statistical inference”, the scientists report in a recent issue of Nature Communications.
In a final test, keas were more likely to take tokens from a researcher who showed a bias for black tokens – that is, one who always reached for black tokens even though there were more orange in the jar. Previously, only humans and chimpanzees were known to integrate this type of social information to make predictions.
The findings indicate that keas, like humans, have something known as “domain general intelligence” – the mental ability to integrate several kinds of information, the researchers argue.
Original article by Virginia Morell, Science, March 3, 2020.
