Necessity may be the mother of invention, but for Bruce the parrot, it is the essence of survival. Despite having a broken beak, the kea from New Zealand has learned to use tools he developed on his own to preen himself.
Bruce was found without the upper half of his beak as a juvenile in 2013. He was nursed back to health at the Willowbank Wildlife Reserve in Christchurch, where he now resides with a flock of kea, an alpine parrot found only in New Zealand. It is not known how Bruce lost his upper beak, though it is suspected it happened in an animal trap.
After his recovery, researchers noticed Bruce was using small pebbles to rid his plumage of mites and dirt—a practice that has never been observed before. Keas traditionally use their beaks to preen themselves.
“Kea do not regularly display tool use in the wild, so to have an individual innovate tool use in response to his disability shows great flexibility in their intelligence,” study author Amalia Bastos, a Ph.D. student at the University of Auckland School of Psychology, tells Eva Corlett for the Guardian. “They’re able to adapt and flexibly solve new problems as they emerge.”
Corlett and her fellow researchers studied Bruce for nine days to learn how he developed his self-care technique on his own and published their findings in the peer-reviewed journal Scientific Reports.
They observed Bruce selecting specific sizes of pebbles that he could fit in his still-intact lower beak. Using his tongue, the parrot holds the small stone in place to preen his plumage. Other scientists were at first skeptical of the findings, but videos show Bruce continually doing what Bastos and others have claimed.
“The main criticism we received before publication was, ‘Well, this activity with the pebbles may have been just accidental—you saw him when coincidentally he had a pebble in his mouth,’” Bastos tells Nicholas Bakalar of the New York Times. “But no. This was repeated many times. He drops the pebble, he goes and picks it up. He wants that pebble. If he’s not preening, he doesn’t pick up a pebble for anything else.”
Kea are a highly intelligent species of parrot, the only one existing in alpine regions. The inquisitive bird has been known to peck apart window trim and wiper blades on cars—and even steal passports from tourists. However, none has ever been observed using pebbles to clean themselves.
As a control, the researchers also watched other kea at the Willowbank Wildlife Reserve. Although many use sticks and other objects for play, no others were seen using small pebbles for preening.
“Kea do not regularly display tool use in the wild, so to have an individual innovate tool use in response to his disability shows great flexibility in their intelligence," Bastos says in a University of Auckland statement. "They’re able to adapt and flexibly solve new problems as they emerge."
At the reserve, Bruce receives soft foods from the staff so he can eat. However, he has also been observed eating harder foods by scraping them against other objects.
“He’ll pick up a piece of carrot and push it against a hard piece of metal or rock and use that to scrape with his lower bill, which again is a feeding behavior we haven’t seen in the other birds,” Bastos tells the Guardian. “It’s not tool use but it is another interesting way he has adapted to his disability.”