Photographs of Bruce handling objects larger than his preening pebbles, namely: (a) a slice of carrot, (b) a stone, (c) a piece of bark, (d) a black token used in previous cognitive experiments he was a part of; a close-up image (e) demonstrates how he uses his tongue and lower mandible to hold these objects. Image credit: Bastos et al., doi: 10.1038/s41598-021-97086-w.
“Most reports of tooling in birds revolve around foraging,” said study lead author Amalia Bastos, a Ph.D. candidate in the School of Psychology at the University of Auckland, and colleagues from the University of Auckland and the ELTE Eotvos Lorand University.
This behavior is more common in captivity. For example, greater vasas use smaller stones to break down shells and then eat them. Kea parrots (Nestor Notabilis ) Learn to insert sticks and other objects in traps for pest species.
” In captivity, kea can also learn to use stick tools to extract food in experimental setting.
“Bruce was found as a juvenile by a researcher at Arthur’s Pass in 2013 with the upper half of his beak missing,” they explained.
It’s unclear how the injury occurred but it was likely caused by a trap .”
” He was taken to South Island Wildlife Hospital where he was treated and returned to health. Bruce now lives in Willowbank Wildlife Reserve Bruce can hold various objects between his lower lip and his lower mandible .”
To prove that his behavior was intentional, scientists monitored Bruce for nine days.
They recorded Bruce manipulating objects and preening, and were able five lines of evidence that proved his intentional tool use.
The first line of evidence the team found was that in over 90% of instances where Bruce picked up a pebble, he then went on to use it to help preen.
Secondly, in 95% of instances where Bruce dropped a pebble, he retrieved or replaced it before continuing to preen.
Third: They also noticed that Bruce chose pebbles that were suitable for preening and not randomly picking pebbles from his environment.
Additionally, from observations of the other 12 kea in the aviary, they also found that no other bird used pebbles while preening, and that when the other individuals did interact with objects, they selected stones of different sizes to those Bruce used.
Bruce’s use of tools highlights the intelligence and versatility of this species alpine parrot,” Bastos stated.
Kea don’t often display tool use in nature, so for someone with a disability to use a tool to help them is a sign of their intelligence. They are able to adapt and solve new problems
This is the first observation of self-care tool usage in a kea. This is the first scientific observation that a parrot uses a pebble to self-care.
A.P.M. Bastos et al. 2021. Self-care tooling innovation for disabled kea Nestor Sci Rep 11, 18035; doi: 10. 1038/s41598-021-97086-w