New York:  Residents of Chicago have been warned to be wary of blackbirds after a spate of dive-bombing attacks on cyclists and pedestrians.

People have complained of being chased for up to 100 yards, being pecked on the head and of having their hair clawed.

The fiercely territorial male red-winged blackbird has been blamed.

It is a common American species and the eight-inch long males have distinctive bright red shoulder patches. Despite their size, they have been known to attack far larger birds, including ospreys, buzzards and hawks. Local ornithologists say similar incidents have happened in previous years during the nesting season.

The attacks bear obvious, though rather less lethal, comparisons to the film The Birds and one of the worst offenders has been nicknamed Hitchcock after the director.

Holly Grosso, a local businesswoman, said she was talking on her mobile phone on a Chicago street last week when Hitchcock went for her. "Something just came down, pecked me in the head, took my hair and started flying away," she said. "It's so bizarre. It's this little bird."

Grosso's colleague, Clare McDermott, said she never cycled to work without wearing a helmet.

Douglas Stotz, an ornithologist, advised anyone targeted by an angry blackbird to stare directly at it. If that failed, barking like a dog should keep it away, he said.