(IMAGE) University of Vienna Caption The choice was between new and familiar images -- it was tested wether the cockatoos act according to the exclusion principle. Credit Copyright: Mark O'Hara Usage Restrictions The image may only be used with appropriate caption or credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.