In an attempt to discuss the mechanism of suspense in his films, Alfred Hitchcock coined the term “MacGuffin.” The technical definition of a MacGuffin, now a common cinematic term, is the plot device upon which the tension of a film is hung—the often intangible item which drives the narrative and maintains an element of suspense. Or, as Hitchcock would describe it: nothing.

Hitchcock’s films typically build a heightened element of suspense for the characters through other cinematic means. As the story unfolds, the reason behind their struggle—the MacGuffin— becomes irrelevant. We merely wish to see the character overcome their obstacles. The MacGuffin of the film, therefore, becomes nothing more than the kickoff point of the character’s struggle. In Psycho (1960), for instance, it is the money stolen by Marion Crane—the theft is her catalyst for ending up at the Bates Motel. In North by Northwest (1959), there are two famous MacGuffins: the government secrets which were being protected, and the true identity of George Caplan. At the conclusion of the film, we never know what the government secrets were and we find out George Caplan doesn’t exist. But by then, those things have become background details to a larger story.

In The Birds (1963), Hitchcock’s primary MacGuffin is hard to identify. Some argue one does not exist, while others suggest the underlying reason why the birds are attacking is the MacGuffin. The avian attacks serve as the chief narrative push and the item upon which all the film’s suspense hangs, but the reason for them never becomes clearly defined.

Others offer the romance between Melanie (Tippi Hedren) and Mitch (Rod Taylor), or, more specifically, the lovebirds from the film’s opening scenes that signify that romance as the film’s MacGuffin. That, however, feels a bit specific. As Hitchcock defines the MacGuffin as “the thing which the characters are after but the audience doesn’t care about,” the relationship between Melanie and Mitch doesn’t quite fit. There is a genuine interest established in the couple’s love affair, as the film spends the first half hour of its runtime primarily on that subject. The first bird attack is a gull which hits Melanie in the head as she leaves Mitch’s lake house after 30 minutes, and it is not until Cathy’s (Veronica Cartwright) birthday party that the full-on assaults start, at over 50 minutes into the picture. Before that, the film is largely a clever story of a girl and a guy shielding their blossoming feelings for one another.

The reason behind the birds attacks, while a curious thing to ponder, doesn’t truly matter. Hitchcock intentionally left the attacks unexplained, which is the primary reason people enjoy theorizing about their symbolic nature, but which also speaks to motivation as the film’s MacGuffin. The characters in The Birds are all after an explanation, they deliberate and converse and accuse about the reasons for the occurrences, but receive no answer. That plot-pushing conflict is exactly the type of power a Hitchcockian MacGuffin holds.

What’s more is the reason for the attacks truly doesn’t matter. By the end of the film, it becomes irrelevant— our sympathies shift to the survival of Melanie and the others. The bird attacks have pushed the characters into a state of concern and suspense, fulfilling the duties of the MacGuffin and transferring our emotional investment to the characters more than an explanation for how the situation started.