Early field primatology tended to focus on individual researchers. Researchers such as Dian Fossey and Jane Goodall and Birute Galdikas are examples of this. In 1960, Jane Goodall traveled to the forest at Gombe Stream in Tanzania where her determination and skill allowed for her to observe behaviors of the chimpanzees that no researcher had seen prior. Chimpanzees used tools made from twigs to extract termites from their nests. Additionally, Dian Fossey's work conducted at the Karisoke Research station in Rwanda proved the possibility of habituation among the mountain gorillas. Fossey learned that female gorillas are often transferred between groups and gorillas eat their own dung to recycle nutrients. The third "trimate", Birute Galdikas, spent over 12 years becoming habituated to the orangutans in Borneo, Indonesia. Galdikas utilized statistics and modern data collection to conclude her 1978 doctoral thesis regarding orangutan behavior and interactions. Long-term sites of research tend to be best associated with their founders, and this led to some tension between younger primatologists and the veterans in the field.