Rhesus macaques on Cayo Santiago (IMAGE) University of Pennsylvania Caption Two subadult in proximity. They share a strong friendship bond. Credit Dr. Lauren JN Brent Usage Restrictions Must have attribution when used. 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.