Andrew DeWoody, Purdue University (IMAGE) Purdue University Caption Andrew DeWoody studies eagles by using DNA in their feathers to track their movements and habits. This technique allows DeWoody to study larger populations and prevents injuries to birds because they aren't captured. Credit Purdue Agricultural Communication photo/Tom Campbell 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.