2 Male Gelada Monkeys Threaten Intruder (IMAGE) University of Pennsylvania Caption Two male gelada monkeys threaten an intruder while grooming with an infant. Credit Clay Wilton Usage Restrictions With 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.