Alfred Hitchcock had a terrific eye for suspense and dramatic tension that he employed while directing over 50 movies. His career, which began in the mid-1920s, started to wind down in the 1960s, but not before his last big hit with the nature horror film, The Birds.

Based on Daphne du Maurier’s 1952 novella of the same name, the environmental attack takes evil out of human hands and makes animals that aren’t typically frightening into monsters. The Birds starts with San Francisco socialite Melanie Daniels (Tippi Hedren) attempting to woo lawyer Mitch Brenner (Rod Taylor) in a small town in Northern California. But her amorous pursuits take a backseat when birds of all kinds start attacking people.

Not only was the movie based on du Maurier’s story, it was also inspired by a real life event. In August 1961, the seaside town of Capitola, California was attacked by flocks of seabirds who crashed into cars and dove into homes while also vomiting anchovies. It was later determined that the birds had eaten toxic algae, causing their erratic and violent behavior. For Hitchcock, it was the opportunity to gather research material that he applied to his horror movie about foul fowl.

Most of the birds in the film were actually real ravens, seagulls, crows, and sparrows that were trained and wrangled by Ray Berwick. The special effects became a team effort handled by multiple studios. At Disney, Ub Iwerks created the effects for the children’s party, the sparrows flying through the chimney, and the first two cuts of the crow attacks; at MGM, Bob Hoag worked on the scene in which Melanie is attacked inside a phone booth. Film Effects of Hollywood founder Linwood Dunn created the attic scene; and Bill Abbott at Fox handled the crow attack sequence.

The Birds reached theaters on March 28, 1963, surprising and frightening audiences with its surprising premise and unwavering intensity. It is considered one of Hitchcock’s greatest films and has been the inspiration for countless animal attack horror movies.