Question: did they use real gorillas in the movie congo

Answer: No, After the success of The First Great Train Robbery, Crichton decided to write a screenplay specifically for Sean Connery, as the character of Charles Munro, an archetypal ``great white hunter'' akin to H. Rider Haggard's hero, Allan Quatermain. The film was envisioned as an homage to classic pulp adventure tales, and Crichton successfully pitched the movie to 20th Century Fox in 1979 without a fleshed out story. The film ran into problems however when Crichton learned that he could not use a real gorilla to portray the character of Amy, which was a breaking point for him and he left the project. From there, it was offered to several directors including Steven Spielberg and John Carpenter who both passed. A brief attempt was made to revive the project in the late 1980s but to no avail. Ultimately Frank Marshall would go on to direct the film in the 1990s with little, if any involvement from Crichton.