Migration dates map (IMAGE) Cornell University Caption This map shows the peak migration date across zones in the United States. Turning out lights and making glass safer February 15–June 15 will prevent collisions throughout spring migration. Credit BirdCast. Usage Restrictions Only for use with articles on the subject of this release. 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.