When audiences left the U.K. premiere at the Odeon, Leicester Square, London, they were greeted by the sound of screeching and flapping birds from loudspeakers hidden in the trees to scare them further.
Alfred Hitchcock revealed on The Dick Cavett Show (1968) that 3,200 birds were trained for the movie. He said the ravens were the cleverest, and the seagulls were the most vicious.
Sir Alfred Hitchcock saw Tippi Hedren in a 1961 commercial aired during the Today (1952) show and put her under contract. In the commercial for a diet drink, she is seen walking down a street and a man whistles at her slim, attractive figure, and she turns her head with an acknowledging smile. In the opening scene of this movie, the same thing happens as she walks toward the bird shop. This was an inside joke by Hitchcock.
Sir Alfred Hitchcock approached Joseph Stefano (screenwriter of Psicosis (1960)) to write the script, but he wasn't interested in the story. The final screenplay (from a Daphne Du Maurier short story) was written by Evan Hunter, best known to detective story fans under the pen name Ed McBain.
Several endings were being considered. One that was considered would have shown the Golden Gate Bridge completely covered by birds.
Alfred Hitchcock: at the start of the movie, man walking two dogs out of the pet shop. The dogs were actually his white terriers named Geoffrey and Stanley.