Innovative problem solving in macaws

Laurie O’Neill,Auguste M P Von Bayern,Rahman Rasyidi,Ronan Hastings,Auguste M P Von Bayern

doi:10.3758/s13420-020-00449-y

Abstract

Behavioural innovations with tool-like objects in non-habitually tool-using species are thought to require complex physical understanding, but the underlying cognitive processes remain poorly understood. A few parrot species are capable of innovating tool-use and borderline tool-use behaviours. We tested this capacity in two species of macaw (Ara ambiguus, n = 9; Ara glaucogularis, n = 8) to investigate if they could solve a problem-solving task through manufacture of a multi-stone construction. Specifically, after having functional experience with a pre-inserted stick tool to push a reward out of a horizontal tube, the subjects were required to insert five stones consecutively from one side to perform the same function as the stick tool with the resulting multi-component construction. One Ara glaucogularis solved the task and innovated the stone construction after the experience with the stick tool. Two more subjects (one of each species) did so after having further functional experience of a single stone pushing a reward out of a shortened tube. These subjects were able to consistently solve the task, but often made errors, for example counter-productive stone insertions from the opposing end, even in some of the successful trials. Conversely, multiple trials without errors also suggested a strong goal direction. Their performance in the follow-up tasks was inconclusive since they sometimes inserted stones into un-baited or blocked ‘dummy tubes’, but this could have been an attention-deficit behaviour as subjects had not encountered these ‘dummy tubes’ before. Overall, the successful subjects’ performance was so erratic that it proved difficult to conclude whether they had functional understanding of their multi-stone constructions.

Highlights

In this manner it is possible to examine if the capacity for flexible tool use is a result of a more general cognitive capacity evolved in response to selection pressures not restricted to the physical domain, or whether more flexible tool-using skills have evolved from a more specialised physical-cognition domain (Kacelnik, 2009; McCormack et al, 2011; Taylor & Gray, 2014)
Three subjects were able to consistently manufacture a multistone construction to obtain the walnut reward. These birds were able to create a functional stone-construction by combining multiple stone components one behind the other to push the walnut out of the tube. Due to their successes coming at different stages of the experiment, and because of some of the behaviours associated with their successful manufacture, it is likely that these successful subjects had a different understanding of their stone constructions and innovated them in different ways
Lady (Ara glaucogularis) manufactured her first successful stone construction in critical test 1 after having the functional experience that a stick tool could push the reward out of the tube. At this stage of the experiment, she had not had a specific positive experience that the stones could be used to obtain the reward in this specific apparatus

Summary

Introduction

Visalberghi & Limongelli, 1994; Visalberghi & Trinca, 1989; von Bayern, Danel, Auersperg, Mioduszewska, & Kacelnik, 2018; Weir & Kacelnik, 2006) These tool-use tasks present subjects with a novel apparatus that requires some sort of behavioural innovation to access a reward. Of particular interest is comparing the performance of species that are habitual tool users in the wild and those that are not, investigating both closely and distantly related species (Auersperg et al, 2011; Auersperg, von Bayern, Gajdon et al, 2011; Lambert et al, 2017; Teschke et al, 2013) In this manner it is possible to examine if the capacity for flexible tool use is a result of a more general cognitive capacity evolved in response to selection pressures not restricted to the physical domain (e.g., general intelligence; Burkart et al, 2017), or whether more flexible tool-using skills have evolved from a more specialised physical-cognition domain (Kacelnik, 2009; McCormack et al, 2011; Taylor & Gray, 2014)

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Conclusion