Fossey's highly personal, detailed account of the ecology and behavior of the mountain gorilla based on her 13 years among "the greatest of the great apes." These highly endangered gorillas are restricted to just six extinct volcanoes in the Virunga mountains, an area 25 miles long and only 6-12 miles wide. She describes habituating her study group. Having named the animals, she follows the life history, diet and sex life of each, offering insight into both the study animals and researcher. Originally published in 1983.