This trend-setting thriller put its director, Dario Argento, on the international map and began a flood of imitative mystery-horror hybrids which dominated Italian genre output in the early 1970s. Tony Musante, best known for the television series Toma, portrays an American who witnesses the murder of a woman at a trendy Rome art gallery. Before long, Musante finds himself targeted by a mysterious killer. Based on a story by Byron Edgar Wallace, Bird and hints at the flamboyance which would become Argento's trademark. This and Argento's subsequent two films Il Gatto a Nove Code and Quattro Mosche di Velluto Grigio were much less horror-oriented than his later work.
~ Robert Firsching, All Movie Guide