Preliminary investigation of foot preference for a string-pulling task in zoo macaws

Cognitive abilities have been found to vary widely among parrots, within and between species, and seem to be related to motor lateralization. Indeed, as shown in Australian parrots and other species, lateralized psittacines perform better in cognitive tests than non-lateralized subjects. The aim of this study was to assess foot preference of seven macaws of three different species (red-and-green macaw, Ara chloropterus; blue-and-yellow macaw, A. ararauna, scarlet macaw, A. macao) during two string-pulling tasks of different complexity (Experiment 1: parallel string, Experiment 2: crossed strings). We also investigated the correlation between the foot preference and the performance of the macaws (as proportion of correct choices during the first pulling-up of the string of the apparatus). Per experiment and per subject, we did ten 1 -h sessions. We video-recorded all pulling-up events during the interaction with the apparatus and collected data from the videorecording using a continuous focal animal sampling. In both experiments, all macaws that interacted with the apparatus solved the tasks. The percentage of correct pulling-up responses ranged from 86 % to 100 % in Experiment 1 and from 40 % to 79 % in Experiment 2. We found foot preferences at the individual level in most of the macaws in both experiments, with the presence of right-footed, left-footed and ambi-preferent subjects. No group-level biases were found. No correlation between foot preference's indices and the percentage of correct choices emerged, suggesting that neither the direction nor the strength of lateralization seem to affect the performance of the subjects. However, as most of the macaws were lateralized and were able to solve the tasks, particularly in Experiment 1, there is a possible correlation with lateralization on the cognitive performance at individual level. Our results increase the knowledge of parrots’ cognitive abilities. However, future studies should be done to increase the sample size and investigate the effect of age, sex and species on foot preference during specific tasks in macaws.