In a park next to the stately New York Public Library, a hawk named Starbuck swoops down from a tree. Frightened pigeons scatter in all directions.

On this blustery morning, Starbuck is hard at work in a pilot program to drive a growing number of pigeons out of Bryant Park, where about 5,000 people spend their lunch hours each day.

"New Yorkers used to complain about muggers and drug dealers here. Now they're complaining about pigeon droppings on their business suits," said Daniel Biederman, executive director of the Bryant Park Restoration Corp., a private, nonprofit organization that helps maintain the 19th-century park.

Falconer Thomas Cullen, 51, was hired to let his trained Harris hawks scare pigeons out of the eight-acre patch of landscaped greenery. The Harris hawk, about 18 inches long with a 45-inch wing span, generally preys on small ground animals.

The restoration group is covering the initial investment of as much as $15,000.

If the hundreds of pigeons at Bryant Park start to find greener pastures -- a trend already noted after just a few days -- the program will continue at the park through the warm-weather months with five hawks, plus a falcon.

"All animals have an instinctive fear of their predators. The idea is that the presence of a hawk will persuade pigeons to settle elsewhere," said Steve Jones, editor of American Falconry, a magazine based in Dayton, Wyo.

In 1996, Cullen set up a bird abatement program at New York's John F. Kennedy International Airport, where as many as 18 hawks and falcons are used to control the gull population above the seaside tarmac. Before the predators were brought in, collisions of birds and planes had caused about $4 million in damage, Cullen said. The damage has been reduced by 60 percent, he said.

In Bryant Park, the hawks work from 9 a.m. to 5 p.m., and Cullen keeps them well-fed so they will scare pigeons for sport rather than food -- and stay within the park.

Still, hawks do wander -- like Galan, who ended up atop a nearby 18-story building. He was found through a radio transmitter Cullen attached to the hawk's leg.