Self-care tooling innovation in a disabled kea (Nestor notabilis)

• Published in: Scientific reports 2021-09, Vol.11 (1), p.18035-18035, Article 18035
• Main Authors: Bastos, Amalia P. M., Horváth, Kata, Webb, Jonathan L., Wood, Patrick M., Taylor, Alex H.
• Format: Article
• Language: English
• Subjects: 631/477; 631/601; Activities of daily living; Animals; Animals, Wild; Behavior, Animal; Birds; Cognitive ability; Grooming; Humanities and Social Sciences; Mandible; multidisciplinary; New Zealand; Parrots - physiology; Science; Science (multidisciplinary); Self Care - instrumentation; Self Care - methods; Species
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-97086-w

Tooling is associated with complex cognitive abilities, occurring most regularly in large-brained mammals and birds. Among birds, self-care tooling is seemingly rare in the wild, despite several anecdotal reports of this behaviour in captive parrots. Here, we show that Bruce, a disabled parrot lacking his top mandible, deliberately uses pebbles to preen himself. Evidence for this behaviour comes from five lines of evidence: (i) in over 90% of instances where Bruce picked up a pebble, he then used it to preen; (ii) in 95% of instances where Bruce dropped a pebble, he retrieved this pebble, or replaced it, in order to resume preening; (iii) Bruce selected pebbles of a specific size for preening rather than randomly sampling available pebbles in his environment; (iv) no other kea in his environment used pebbles for preening; and (v) when other individuals did interact with stones, they used stones of different sizes to those Bruce preened with. Our study provides novel and empirical evidence for deliberate self-care tooling in a bird species where tooling is not a species-specific behaviour. It also supports claims that tooling can be innovated based on ecological necessity by species with sufficiently domain-general cognition.