Grauer's Gorilla (IMAGE) Smithsonian Tropical Research Institute Caption Smithsonian Tropical Research Institute staff scientist and his team risked their lives to estimate the number of Grauer's gorillas remaining in 1996, 17,000. A new survey puts the number of gorillas at 3,800. Credit Jefferson Hall, STRI Usage Restrictions Credit: STRI 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.