Parrots and crows show their inventive side

A team of researchers from the Universities of Oxford and Vienna have tested the technical skills and innovation abilities of two of the most intelligent birds known, kea parrots and New Caledonian crows. New Caledonian crows regularly use and manufacture complex tools in the wild to extract food, feats that they repeat in the laboratory. Kea parrots, although not natural tool users, are known for their inquisitiveness, and have recently shown in captivity the ability to use compact objects as tools. Comparing the problem-solving performance of these two animals is helping to reveal how the evolution of differences in intelligence depends on the ecology of each species. A report of the research is published this week in the journal PLoS ONE . Dr Alice Auersperg of the University of Vienna, who led the study, said: 'We confronted members of both species with a 'Multi Access Box' in which a food reward could be acquired by applying one of four different methods: pulling a string tied around the reward, opening a window by pulling a hook-shaped lever, inserting marbles into a curved pathway so that they rolled down and knocked the food reward out of place, or inserting a stick-like tool into the side of the box to poke the food out.' She adds: 'Our aim was to examine the birds' performance in a battery of different tasks. We allowed them to choose which task to tackle first, and once they were proficient with it, we blocked it to see how long and in which way they proceeded to the next solution.' Six kea and five New Caledonian crows participated in the study, but only one of each, Kermit (a parrot) and Uek (a crow), mastered all four tasks.