<human>:  How many gorillas did the famous gorilla researcher Dian Fossey study?
<bot>: She studied a total of 87 gorillas in her lifetime, including her most famous study subject, Digit. Digit was a western lowland gorilla who lived in the Virunga Mountains of Rwanda. Dian Fossey was the first person to study gorillas in detail, and she published several books about her research. She was killed in 1985 by poachers who were trying to steal her research materials.