Narwhal release (IMAGE) University of California - Santa Cruz Caption In this drone image, researchers in the water watch as a narwhal swims away with a physiological monitoring tag (yellow instrument attached with suction cups on the back), which will record heart rate, breathing rate, stroking frequency, and depth for 1-3 days. Credit Photo credit, Eva Garde, Greenland Institute of Natural Science. Usage Restrictions For use only with news coverage 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.