She is the world 's foremost expert on chimpanzees . Goodall is best known for her 45-year study of social and family interactions of wild chimpanzees in Gombe Stream National Park , Tanzania . Considered to be the world 's foremost expert on chimpanzees , Goodall is best known for her 45-year study of social and family interactions of wild chimpanzees in Gombe Stream National Park , Tanzania .