Sampling plants for gorillas (IMAGE) University of California - Davis Caption Tierra Smiley Evans from UC Davis and Gorilla Doctor Fred Nizeyimana collect saliva samples from chewed plants discarded by mountain gorillas in Uganda's Bwindi Forest in 2013. Credit (Gorilla Doctors) Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.