How far will a behaviourally flexible invasive bird go to innovate?

Corina J. Logan

doi:10.1098/rsos.160247

Abstract

Behavioural flexibility is considered a key factor in the ability to adapt to changing environments. A traditional way of characterizing behavioural flexibility is to determine whether individuals invent solutions to novel problems, termed innovativeness. Great-tailed grackles are behaviourally flexible in that they can change their preferences when a task changes using existing behaviours; however, it is unknown how far they will go to invent solutions to novel problems. To begin to answer this question, I gave grackles two novel tests that a variety of other species can perform: stick tool use and string pulling. No grackle used a stick to access out-of-reach food, even after seeing a human demonstrate the solution. No grackle spontaneously pulled a vertically oriented string, but one did pull a horizontally oriented string twice. Additionally, a third novel test was previously conducted on these individuals and it was found that no grackle spontaneously dropped stones down a platform apparatus to release food, but six out of eight did become proficient after training. These results support the idea that behavioural flexibility is a multi-faceted trait because grackles are flexible, but not particularly innovative. This contradicts the idea that behavioural flexibility and innovativeness are interchangeable terms.

Highlights

While behavioural flexibility is considered a key factor in the ability to adapt to changing environments, it is difficult to quantify because it might be expressed in some contexts but not others [1,2]
No grackle innovated stick tool use even after observing a human experimenter demonstrate the solution many times. Their performance is similar to Goffin cockatoos where most individuals did not innovate stick tool use and some did not learn by observing a conspecific demonstrator [42]
Though grackles are generalist foragers, perhaps they attend to particular features of their environment that differ from generalist foragers in other species where one or more individuals have 7 innovated tool use (New Caledonian crows [43], keas [23] and Goffin cockatoos [42])

Summary

Introduction

While behavioural flexibility is considered a key factor in the ability to adapt to changing environments, it is difficult to quantify because it might be expressed in some contexts but not others [1,2]. Behavioural flexibility is one trait that can contribute to facilitating innovations, defined as inventing a new behaviour or using an existing behaviour in novel circumstances [2]. Because behavioural flexibility is multi-faceted, and because the links between behavioural flexibility, problem solving and innovativeness are rarely investigated from multiple angles in a given species (but see [8]), it is poorly understood how behaviour is used to react to changing circumstances

Methods

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Discussion

Conclusion