On August 18, 1961, residents in the town of Capitola, California, awoke to find sooty shearwaters slamming into their rooftops, and their streets covered with dead birds. News reports suggested domoic acid poisoning (amnesic shellfish poisoning) as the cause. According to the local Santa Cruz Sentinel, Alfred Hitchcock requested news copy in 1961 to use as "research material for his latest thriller". At the end of the same month, he hired Evan Hunter to adapt Daphne du Maurier's novella, "The Birds", first published in her 1952 collection The Apple Tree. Hunter had previously written "Vicious Circle" for Alfred Hitchcock's Mystery Magazine, which he adapted for the television anthology series Alfred Hitchcock Presents. He also adapted Robert Turner's story "Appointment at Eleven" for the same television series. Hunter later suspected that he was hired because he had demonstrated he could write suspense (with the 87th Precinct novels, as Ed McBain) and because his novel The Blackboard Jungle had received critical acclaim. The relationship between Hunter and Hitchcock during the creation of The Birds was documented by the writer in his 1997 autobiography Me and Hitch, which contains a variety of correspondence between the writer, director and Hitchcock's assistant, Peggy Robertson.
Hunter began working on the screenplay in September 1961. He and Hitchcock developed the story, suggesting foundations such as the townspeople having a guilty secret to hide, and the birds an instrument of punishment. He suggested that the film begin using some elements borrowed from the screwball comedy genre then have it evolve into "stark terror". This appealed to Hitchcock, according to the writer, because it conformed to his love of suspense: the title and the publicity would have already informed the audience that birds attack, but they do not know when. The initial humor followed by horror would turn the suspense into shock.
Hitchcock solicited comments from several people regarding the first draft of Hunter's screenplay. Consolidating their criticisms, Hitchcock wrote to Hunter, suggesting that the script (particularly the first part) was too long, contained insufficient characterization in the two leads, and that some scenes lacked drama and audience interest. Hitchcock at later stages consulted with his friends Hume Cronyn (whose wife Jessica Tandy was playing Lydia) and V.S. Pritchett, who both offered lengthy reflections on the work.
Hitchcock decided to do without any conventional incidental score. Instead, he made use of sound effects and sparse source music in counterpoint to calculated silences. He wanted to use the electroacoustic Mixtur-Trautonium to create the birdcalls and noises. He had first encountered this predecessor to the synthesizer on Berlin radio in the late 1920s. It was invented by Friedrich Trautwein and further developed by Oskar Sala into the Trautonium, which would create some of the bird sounds for this film.
The director commissioned Sala and Remi Gassmann to design an electronic soundtrack. They are credited with "electronic sound production and composition", and Hitchcock's previous musical collaborator Bernard Herrmann is credited as "sound consultant".
Source music includes the first of Claude Debussy's Deux arabesques, which Tippi Hedren's character plays on piano, and "Risseldy Rosseldy", an Americanized version of the Scottish folk song "Wee Cooper O'Fife", which is sung by the schoolchildren.
The special effects shots of the attacking birds were done at Walt Disney Studios by animator/technician Ub Iwerks, who used the sodium vapor process ("yellow screen") which he had helped to develop. The SV process films the subject against a screen lit with narrow-spectrum sodium vapor lights. Unlike most compositing processes, SVP actually shoots two separate elements of the footage simultaneously using a beam-splitter. One reel is regular film stock and the other a film stock with emulsion sensitive only to the sodium vapor wavelength. This results in very precise matte shots compared to blue screen special effects, necessary due to "fringing" of the image from the birds' rapid wing flapping.