Bruce, a kea parrot at New Zealand's Willowbank Wildlife Reserve, lost his upper beak in an accident as a young bird. This, however, did not stop him from becoming the dominant male in his 12-member 'circus' (9 males, 3 females), a feat documented in a new paper in Current Biology. His secret? A unique fighting method researchers have dubbed 'beak-jousting'.
Bruce was already known for his ingenuity. In 2021, scientists from the University of Auckland's Kea Animal Minds Lab observed him using small pebbles to preen himself - a behavior he invented independently, as other keas only played with larger pebbles and never used them for grooming. This evidence of problem-solving and potential deliberate tool use is why his caretakers have never fitted him with a prosthetic, believing it would cause him stress and force him to re-learn his adaptations.
Now, Bruce is challenging 'contest theory,' which assumes the larger, better-armed opponent usually wins. Over four weeks, researchers observed 162 male-male interactions. Bruce was involved in 36 and won them all, securing his alpha status. He also had the lowest stress hormone metabolites, priority access to four central feeding stations, and was the only bird to have a non-mate clean debris from his lower beak.
The key to his success and chill demeanor is his jousting technique. At close range, he thrusts with his neck; from farther away, he adds a run or jump. While other males mostly bite downward onto an opponent's neck, Bruce uses forward thrusts targeting the back, head, wings, and legs. He kicks at the same rate as others but uses his half-beak much more frequently.
There are only two other comparable cases in scientific literature: a chimpanzee named Fabian, observed by Jane Goodall, who achieved beta status after losing arm use by developing unusual charging displays, and an old Japanese macaque who maintained alpha status by allying with the alpha female. Bruce, however, achieved alpha status on his own through dominance.
"Bruce shows us that behavioral innovation can help bypass physical disability, at least in species with the cognitive flexibility to develop new solutions," said co-author Alexander Grabham of the University of Canterbury. He noted the findings raise a welfare question: "if a disabled animal can innovate its way to success, well-intentioned interventions like prosthetics might not always improve their quality of life. Sometimes the animal can do better without help."