Monarchs in Mexico (IMAGE) University of California - Riverside Caption Monarchs overwintering in Mexico closely observed by a black-headed grosbeak, a known monarch predator. Credit Lincoln Brower/Sweet Briar College Usage Restrictions post with credit 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.