Red Colobus in Tree (image) University of California - Berkeley Caption A red colobus monkey prepares to munch on the bark of Eucalyptus grandis, a non-native estrogenic tree in Kibale National Park. Greater consumption of estrogenic plants is linked to altered hormone levels and changes in behavior, according to a new UC Berkeley-led study. Credit Julie Kearney Wasserman Usage Restrictions All rights reserved. Commercial use prohibited. 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.