Can Ravens Think in the Abstract? (IMAGE) University of Houston Caption This sketch describes the experimental setup, showing ravens a) in the observed condition, with the window open and the subject caching food in the visual presence of another raven; b) with the cover of the window closed, and the subject caching food in visual isolation, and c) with the window cover closed but a peephole open, as the subject caches food in the absence of behavioral cues but with audio playback of raven sounds. Credit T. Bugnyar Usage Restrictions None 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.