Raven with GPS-tracker (image) University of Vienna Share Print E-Mail Caption Raven with GPS, tracking the position of the animal every hour. Credit Matthias Loretto, University of Vienna Usage Restrictions The image may only be used with appropriate caption or credit. Share Print E-Mail 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.