As with many people here, I seen the movie The Birds in advance of reading the story. It has only been recently I have become a Du Maurier fan and whilst the movie says that it is based on Du Maurier's short story, and that there are birds in it, that is basically where the comparisons end.
Du Maurier's story is much more chilling. Whilst Hitchcock is a master of suspense, there is something more real about Du Maurier's tale, centering around a family and set in England, than there is about Tippi Hendron chasing after a man on a whim with budgies.
It is a short story and very easily readable and Du Maurier has this ability that most film directors lack in images, that she can convey in words, and it is that true suspense, that chilling factor that so many horror movies and books fail to truly encapsulate.