String-pulling in African grey parrots (Psittacus erithacus): performance in discrimination tasks

Abstract

Abstract Many studies have used the string-pulling paradigm in order to assess causal understanding of the physical domain in a great variety of species of birds, primates and other mammals. Another area of interest is how subjects manage to solve these tasks, i.e., through trial-error learning, relying on perceptual cues, or through some kind of insight. In our study, we tested three juvenile female African grey parrots (Psittacus erithacus) on some string discrimination tasks. Our individuals seemed to base their choices on associations with perceptual cues rather than in a functional understanding of the tasks. They relied on trial-error learning instead of insight, and their performances were influenced by operant conditioning. However, their behaviour was goal-directed, as they frequently changed their first choice once they realized that they had chosen the wrong string.