Sigourney Weaver is superb in her role as the world famous primatologist Dian Fossey who devoted herself to the study and protection of mountain gorillas in Rwanda.  We witness how she gradually won the trust of the gorillas by spending lots of time living among them and acting like one of them.  She experienced serious conflicts with poachers and surrounding tribes in whose eyes her efforts deprived them of their livelihoods - ultimately ending in her murder.  The film is extraordinary in showing the gorillas in their natural habitat, less so in exploring Dian Fossey's scientific background and compulsion to stay with the gorillas at the expense of close relationships with other human beings.  Interesting local note: Fossey enrolled in a pre-vet course at UCD.  With Bryan Brown as the National Geographic photographer, John Omirah Miluwi as tracker Sembagare, and Iain Cuthberson as Dr. Louis Leakey.