New Zealand Parrot With Half a Beak Turns Handicap Into Strength

A little over a decade ago, the future looked bleak for a young New Zealand parrot who was crippled and frail. Defying all odds, Bruce has today established himself as a dominant male.

The Unexpected Rise of Bruce

Discovered in 2013 in the Canterbury region, this young kea (Nestor notabilis) had lost the upper portion of his beak under mysterious circumstances. With the species deemed threatened, the bird was taken in by the Willowbank Nature Reserve team near Christchurch.

Although caretakers initially believed they were dealing with a female named Kati, DNA analyses revealed that he was in fact male. Renamed Bruce, the bird quickly established himself within the Willowbank kea group, which comprised nine males and three females.

According to Ximena Nelson of the University of Canterbury, Bruce has transformed his handicap into a genuine strength, using the lower part of his beak, straight and sharp, as a weapon. “Even though the other males are considerably larger [normally exceeding a kilo], their upper jaw, which is rounded, covers him,” explains the researcher. “Their pecking blows do not have the same impact as Bruce’s.”

Involved in 36 of the 162 documented aggressive interactions among Willowbank’s male keas, the resilient parrot consistently came out on top. Other indicators of his status included priority access to the four feeders inside the enclosure and receiving care from individuals of lower rank, who helped to clean the underside of his beak or to smooth his feathers. “A unique treatment within the enclosure,” notes Nelson.

A Well-Established Status

Blood analyses revealed notably lower corticosteroid levels (the stress hormone) in Bruce compared with the other males. According to the authors of the new study, published in the journal Current Biology, his status was so firmly established that he only needed to display aggression for a fraction of the time recorded for his rivals.

“With the exception of humans, this represents the first example of a physically compromised individual capable of attaining and sustaining a dominant male status solely through behavioral adaptation,” the researchers write.

“A handicap is not always a weakness, and in Bruce’s case, outfitting him with a beak prosthesis would likely have worked against him,” notes Nelson. “I deeply admire this bird, who fights with determination when necessary, yet does not harass the other males.”

Earlier this year, unlikely behaviours were documented in male kakapos, another New Zealand parrot species.