Fossey, Dian (1932-1985) was an American zoologist who studied the mountain gorilla of the Virunga Mountains in east-central Africa. She founded the Karisoke Research Center in Rwanda and lived there in near-isolation over an 18-year period. Fossey's research on wild mountain gorillas led to efforts to protect this rare and endangered species. Her 1983 book, Gorillas in the Mist, and a 1988 film of the same name, presented her findings on the habits of these animals and drew world attention to their plight.

Mountain gorillas are one of three types of gorillas, which are the largest members of the ape family. The other two are the western lowland gorilla and the eastern lowland gorilla. A large male gorilla living in the wild may weigh 450 pounds (200 kilograms). Standing up on its legs, it may be 6 feet (1.8 meters) tall. Female gorillas usually weigh about 200 pounds (90 kilograms) and are shorter than males. Mountain gorillas live in the wild only in a small area of mountainous forestland that covers the sides of several extinct volcanoes in Rwanda, Uganda, and Congo (Kinshasa), formerly known as Zaire. There are estimated to be fewer than 450 mountain gorillas in the wild left in the world. They are threatened in part because of the destruction of their habitat and because they are hunted by poachers and inadvertently injured in traps set for other animals by hunters.

Fossey was born in San Francisco. She received a bachelor's degree in occupational therapy from San Jose State College (now San Jose State University) in 1954. After graduating, she accepted a job as an occupational therapist at the Kosair Crippled Children's Hospital in Louisville, Kentucky.

In 1963, inspired by a book about mountain gorillas by the zoologist George Beals Schaller, Fossey got a bank loan for $8,000, took a leave of absence from her job, and went to Africa for seven weeks.

Fossey visited the camp of British anthropologist Louis Seymour Bazett Leakey, in Olduvai Gorge, Tanzania. Leakey was a renowned scientist who had made important discoveries concerning the ancestors of today's humans. He also facilitated the work of several zoologists studying primates, among them Jane Goodall and Birute Galdikas. At Olduvai Gorge, Leakey and his team were excavating fossils of ancient humans. After meeting with Leakey and touring the excavation site, Fossey traveled to Congo (Kinshasa), where she first saw the mountain gorillas.

Although Fossey returned to her job in Kentucky at the end of the seven-week visit, the experience of having observed the gorillas had made a strong impression on her. She wrote several articles on her experiences in Africa, which were published in a Louisville newspaper. In 1966, Leakey came to lecture at the University of Louisville. Fossey met with him during this visit, and he proposed that she return to Africa to undertake a long-term study of the mountain gorilla. In December of 1966, after Leakey had secured funding for the study, Fossey quit her job and left for Africa.

Fossey visited briefly with Jane Goodall, a British zoologist working with chimpanzees in Tanzania. Goodall gave Fossey–who had no formal training in fieldwork or data collection–an informal two-day course in these essential subjects.

By mid-January of 1967, Fossey had arrived at George Schaller's old camp in Congo (Kinshasa). She set up camp in a tent 7 feet by 10 feet (2.1 meters by 3 meters) that served as a combined bedroom, office, and bath. She began tracking and observing three family groups of gorillas. She was forced to abandon this site in July of 1967 because of a civil war being waged in Congo. In September of 1967, she established a research site on the slopes of the Virunga Mountains in Rwanda. Fossey named the site the Karisoke Research Center, after the neighboring Karisimbi and Visoke mountains.

Fossey focused her study on 4 family groups, with a total of 51 gorillas among them. Initially, she observed the gorillas from a distance. But eventually, she decided to attempt to gain the animals' trust and acceptance so she could study them at close range. She learned to mimic the habits and sounds of the animals, hoping these actions would make her seem less like an outsider to the apes. Her approach was successful, and in time the animals became comfortable with her presence, even allowing her to touch them and voluntarily touching her.

Fossey made many important observations about the animals. Her findings dispelled the myth of the gorillas as violent, menacing creatures. She learned that they had strong family ties within each group. They were generally peaceful but would fight to protect an infant in the group. They showed great kindness toward wounded or weaker members of their group. Fossey claimed that the gorillas had distinct personalities, and she named each one she studied.

Fossey also observed that the gorillas had distinct facial characteristics, especially their noses. She cataloged more than a dozen different sounds that the animals made, including chuckling, grunting, and growling. Fossey tracked the distance these nomadic animals traveled each day, and she determined that they are almost exclusively vegetarians.

Fossey did acknowledge that, although the gorillas were generally pacifists, they would fight if threatened. She documented instances where a poacher had to kill a dozen adult apes to capture one baby gorilla. She also reported that the animals were capable of violence toward members of their species, citing evidence of infanticide and cannibalism.

Fossey worked at Karisoke for almost 18 years. At first she worked virtually alone. In later years a variety of student volunteers joined her. During the time she conducted her research, she was plagued by a number of health problems, including asthma, emphysema, and a serious calcium deficiency. She also suffered a number of broken bones and other injuries not easily treated because she was in such a remote area.

Fossey took several hiatuses from her work in Africa. In 1970, she began coursework at Cambridge University in England to earn a doctoral degree in zoology. In 1974, she returned to Rwanda. From March 1980 to August 1982, she was a visiting professor at Cornell University in New York. During this time she wrote Gorillas in the Mist. She resumed her work at Karisoke in 1983, telling reporters she was more comfortable with gorillas than people.

Over the course of her study of the mountain gorillas, Fossey had become very critical of the local government and especially of the poachers who killed and injured gorillas and the herdsmen who encroached on the animals' habitat. Her hostility increased in 1977, when Digit, a young male gorilla who was a favorite of hers, was killed by poachers. She is said to have sabotaged hunters' equipment, dismantling snares and traps, and to have intimidated hunters and their families. Her actions toward the hunters, poachers, and cattle farmers, as well as government officials, became increasingly aggressive over time. She also began raising funds for antipoacher patrols and equipment. In 1977, she founded the Digit Fund, later renamed the Dian Fossey Gorilla Fund.

In December of 1985, Fossey was found dead in her cabin at Karisoke. She had been brutally murdered, her skull split by a large knife. A Rwandan court charged Wayne McGuire, an American graduate student working as a research assistant to Fossey, with her murder. He was tried in absentia, found guilty, and sentenced to death. McGuire, who had returned to America, denies the charges, and since the United States has no extradition treaty with Rwanda, he cannot be forcibly returned there for his sentence to be carried out. Some United States officials believe that Fossey may have been murdered by poachers enraged by her efforts to protect the gorillas and their habitat. She was buried at Karisoke in the cemetery she had created for her gorillas. Today, the Dian Fossey Gorilla Fund works to carry out the mission upon which she embarked in 1966.