Mitch Irwin and Karen Samonds (IMAGE) Northern Illinois University Caption Northern Illinois University scientists Mitch Irwin and Karen Samonds have been studying Madagascar's diademed sifakas for the past 20 years. Credit Mitch Irwin, Northern Illinois University Usage Restrictions Please use proper credit. 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.