Mute and whooper swans (IMAGE) University of Exeter Caption Mute and whooper swans along with other species at Caerlaverock Credit Paul Rose Usage Restrictions This image may only be used with reports of this research License Original 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.