Stimulus enhancement in kea, Nestor notabilis, in an object choice task

Previous studies illustrated that kea, Nestor notabilis, can apply socially acquired information to solve both simple and complex tasks. However, evidence of which social learning mechanisms kea utilize is still vague. Therefore, in this study, we investigated the role of stimulus versus local enhancement as mechanisms of social learning in an object choice task. We presented 10 kea individuals with objects of four different shapes and nine different colours and tested whether observer kea would copy the object and/or apparatus choice of two demonstrator kea, which were given free choice. This experimental setup significantly decreased training rotations for demonstrators and led to randomization across trials, thus presenting a promising new technique for future studies. Overall, observer kea chose the same objects more often than expected by chance, suggesting some evidence for stimulus enhancement as the primary social learning mechanism. Meanwhile, we find no evidence for local enhancement. These results are in line with kea behavioural ecology as an inquisitive island species that spends a lot of time gathering information about objects (i.e. stimuli). Additionally, highly fluctuating resource availability and depletion rates in their natural environment could make the information of locality less valuable to them. This study helps explain ambiguous results from past experiments and supports distinguishing the different processes at play in the social learning of kea. To understand the full picture of social learning in kea, less complex mechanisms, such as stimulus enhancement, will need to be tested and excluded in future experiments. (c) 2025 The Author(s). Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/).

• Motor Imitation in Kea (Nestor notabilis) Parrots.

Veterinärmedizinische Universität Wien