Credit (or blame) the Bard for the much-admired, much despised starling

Of the 35,000 lines in Shakespeare's plays, only one mentions the diminutive, sinewy, and talented European starling.

But that solitary reference led to a misguided attempt to import starlings for a Shakespeare festival in New York in the late 19th century. The birds evidently fell in love with the New World, and very definitely with each other.

Today, 250 million starlings inhabit North America from Mexico to the Yukon, bedeviling homeowners, car owners, farmers, and birders. In recent winter censuses, one in every six birds in Philadelphia was a starling.

"They came into a country, and took it over," said Jeffrey Homan, a U.S. Department of Agriculture research biologist.

Sometimes flying in undulating swarms of thousands - the sunset light glinting spectacularly off their wings - they are aggressive, noisy, raucous, and disrespectful of other bird life. They are prodigious consumers of almost anything and prodigious producers of droppings.

A USDA study about to be published blames starlings for up to $68 million in annual losses to Pennsylvania's top dairy-producing counties, which include Chester County. Starlings are eating feed intended for cows. Garden State farmers have similar complaints.

Despite attempts to control them, including an infamous one in New Jersey, starlings rule the roosts in the suburbs and the city.

"They're the ultimate adaptive species," said Keith Russell, a Philadelphian and ornithologist with the National Audubon Society.

Like other bird specialists, he has mixed feelings about them. He admires their intelligence. Members of other species routinely die crashing into glass facades and windows, which they fail to identify as barriers. But not the starling. "Starlings have learned what glass is," he said.

If you're walking around Center City these days, high above you in building nooks and crevices starlings are breeding and nesting. Expect a new generation next month.

Russell says their resourcefulness probably wells from those hard, ancestral days in the old country when they had to make homes in rocks and cliff faces. For the modern starling, a city is almost too good to be true.

Starlings can nest almost anywhere they find an opening, and Russell says Center City offers "trillions" of potential homes.

Birders don't like them because they are ruthless in evicting other species, such as purple martins, from their tree-hole homes.

Russell says the first starling appearance in Philadelphia was documented in 1904 at Woodlands Cemetery. "That would have to be those New York birds," Homan said.

Those birds - estimates range from 40 to 100 - were imported to add authenticity to a Shakespeare festival in Central Park. Other attempts had been made to introduce starlings, said Doug Wechsler, bird specialist at the Academy of Natural Sciences, but this one was a rousing success.

The starling had made a cameo in  Henry IV, Part I, when the character Hotspur conceives a plan to drive the king nuts. While the king sleeps, Hotspur plots: he will stick a starling next to his ear to repeat "Mortimer," the name of Hotspur's brother-in-law, whom the king is holding captive.

Their screeching voices notwithstanding, starlings have remarkable abilities as mimics. Mozart was known to have a pet starling who allegedly learned his melodies and composed its own variations.

"They like a lot of flats and sharps," said Cornell University ornithologist Kevin McGowan. "Their music isn't quite as tonal as we like." McGowan said his sister-in-law taught a starling to tweet "La Cucaracha."

"I do appreciate their talent," he said, "and you have to admire their success."

However, they have been implicated in $800 million of annual crop-related losses nationwide; swarms of them have been sucked into plane engines, causing damage; and only a car-wash owner could love the droppings.

Those droppings and their effects on the spread of disease have become hot research topics, said George Linz, of the USDA's National Wildlife Research Center in North Dakota.

The agency does get involved in starling-control attempts when requested. After a USDA pesticide operation in central New Jersey two years ago, hundreds of dead birds rained from the sky, to the surprise of the local populace.

But Harris Glass, Pennsylvania's USDA wildlife services director, says the agency typically proposes nonlethal methods, such as cutting down starling-friendly trees and setting up nest barriers on buildings. "We're not out to eliminate the species," he said.

Serious birders such as Frank Windfelder, head of the Delaware Valley Ornithological Club, wouldn't mind seeing fewer of them.

"There's kind of a history of animosity between birders and starlings," said Cornell's McGowan.

With Windfelder, the animosity has a personal aspect. Starlings keep eating the suet he puts out for the woodpeckers. And he recalled that years ago he unwittingly had parked his car under a starling-populated tree near Northeastern Hospital, where his wife was giving birth to their daughter.

"I came out after a couple of hours," he said, "and the car was a different color."