Dr. Valentina Mella with Koala (IMAGE) University of Sydney Caption Dr. Valentina Mella with koala in Gunnedah, NSW, Australia. Credit University of Sydney Usage Restrictions For this story only. 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.