Eastern Hoolock Gibbon (IMAGE) Duke University Caption The Eastern hoolock gibbon is an IUCN-listed endemic species threatened by the spread of tree plantations in Southeast Asia. A new study identifies hundreds more unlisted species that are also threatened. Credit Binbin Li Usage Restrictions None 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.