Meet Bruce, the disabled kea parrot who is the boss of his flock

A parrot missing half his beak has become top bird at New Zealand’s Willowbank Wildlife Reserve. Named Bruce, he wins every fight with other kea parrots. He also gets priority access to food.

This observation has made scientists question their ideas about disabilities in animal social groups. Bruce showed that a physical disadvantage doesn’t have to hold an animal back. Sometimes the right moves and a little creativity can make all the difference.

Researchers shared this finding April 20 in Current Biology.

Willowbank’s kea live in a large aviary with trees and a stream. Visitors who stop by often fail to notice the parrots snoozing among the leaves. But when they spot Bruce, they always make the same comment, says behavioral ecologist Alex Grabham: “Look at that poor bird.”

That pity is misguided, says Grabham. He’s part of a team studying kea at the University of Canterbury in Christchurch, New Zealand. That team tracked how Bruce interacted with his flock. (A group of kea is called a circus, reflecting the birds’ playful nature.) Like other parrots, kea have a social hierarchy. This is a ranking system where some birds are in charge; others follow the leader. Birds compete for the top spot by fighting, squawking or puffing up feathers.

Meet Bruce, the disabled kea parrot that managed to become the alpha male of his flock.

Grabham’s team spent four weeks recording 162 physical confrontations between the nine males in Bruce’s circus. Bruce won all 36 of his. Without a doubt, he was the top kea.

What’s more, he’s the first disabled animal to be recorded achieving top status within a group, at least without support from an able-bodied ally. (Faben was a dominant, or “alpha,” male chimpanzee living at Gombe National Park in Tanzania. He lost his top rank after polio paralyzed his arm. Faben’s brother took over his alpha status, but also became his ally. Faben then worked his way back to second place after perfecting a charging technique to bat away rivals.)

Parrot jousting

Also key to Bruce’s success: an unusual combat technique. Other kea tend to rely solely on kicking to repel other birds. Bruce supplemented his kicks with a unique jousting technique. He jabbed at rivals with his exposed lower beak.

Grabham’s team filmed 109 more confrontations between Bruce and the other birds. During these, Bruce kicked slightly more than he jousted. But jousting proved much more effective. Jousting drove off his opponent 73 percent of the time. When Bruce kicked, he drove them off just 48 percent of the time.

As another kea approaches, Bruce (seen here on the right) jabs with his half a beak. This fighting style has helped the disabled parrot win alpha status among his circus in New Zealand.Ximena Nelson

Bruce’s top spot comes with perks. Other male kea will preen Bruce, helping to clean parts of his beak that he cannot reach. This is highly unusual among kea. Normally, they only preen their mates. The lower another male’s rank, the more likely he was to preen Bruce. This behavior mimics hierarchical grooming seen in chimps.

Lower-ranked birds also gave Bruce first dibs on food. The birds’ food was spread mostly between four central feeders. Over the four weeks that Grabham’s team analyzed Bruce, he was the first to dine at those feeders 83 percent of the time. On four days, the other birds gave Bruce 15 minutes of alone time with all four feeders. Later, they ate his leftovers.

Another kea preens Bruce (left). This helps remove food that gets stuck in Bruce’s beak. Alex Grabham

In many animal societies, top status comes at a cost. “An animal that is high up in the dominance hierarchy has to defend that position constantly,” says Amalia Bastos. She’s a comparative psychologist at the University of St Andrews in Scotland who used to study Bruce. Alpha male baboons, for instance, show higher levels of stress hormones called glucocorticoids (Glu-ko-KOR-ti-koids).

Grabham’s team measured those hormones in the birds’ droppings. Bruce, it turns out, was the most chill kea in his circus. It isn’t yet clear why. But Grabham thinks that Bruce is so dominant that other kea don’t mount any serious challenges to his throne. “He isn’t going to be followed around and beaten up or bullied or chased,” Grabham says. And Bruce “knows that.”

It’s unclear whether Bruce would have thrived as well in a wild circus as he has at Willowbank. Bastos points out that with his damaged beak, Bruce might struggle with tougher foods during the winter. In the wild, most kea circuses don’t have a fixed hierarchy. Birds join and depart groups throughout the year, constantly changing the rankings. For now, in Willowbank’s strict hierarchy, Bruce is boss.  

This isn’t the first study to show Bruce is capable of innovation. In 2021, researchers reported his self-preening technique. He uses pebbles to clean his feathers. “Bruce has now shown twice that being different is not necessarily disadvantageous,” Bastos says.

Bruce gained renown a few years ago for showing tool use. To groom himself, the parrot would select a pebble and hold it just so. This pebble “tool” overcame the lack of a part of his upper beak.