By Jane O'BrienBBC News, Washington
It's William Shakespeare's 450th birthday - but in the US not everybody is celebrating his legacy.
Birds feature prominently in Shakespeare's plays and poetry. Choughs, wrens, cormorants, owls, nightingales, larks and some 60 other species all have their place in the canon.
Such references have inspired bird lovers for centuries.
So much so that in 1890, a German immigrant named Eugene Schieffelin decided it would be a great idea to introduce as many of Shakespeare's birds as possible to North America.
One cold winter's day he released 60 starlings into New York's Central Park in the hope they would start breeding.
Unfortunately, they did.
"The cormorant is a voracious fishing bird," says Shakespeare Theater Company's Drew Lichtenberg. In Coriolanus there's reference to the "cormorant belly of Rome".
Sometimes Shakespeare uses birds because their names conjure an image or simply sound interesting. In The Tempest one character says he can "make a chough of as deep chat".
After Romeo and Juliet consummate their marriage they hear a bird singing. They argue over whether it's a nightingale, a bird of the night, or a lark which means it's morning and Romeo must leave.
"When the wind is southerly I can tell a hawk from a handsaw," says Hamlet, seemingly describing how he can feign madness when it suits him.
In Macbeth, Shakespeare turns to birds of the night, says Lichtenberg. After the murder of Duncan, Lady Macbeth hears the screech of an owl and never regains her sanity. It was the owl that shrieked, the fatal bellman which gives the sternest goodnight.
The US is now home to an estimated 200 million European starlings. Thickset and pugnacious, starlings are the bruisers of the avian world.
And they are now such a nuisance they are one of the few bird species unprotected by law.
"Starlings are lean and mean. In the industry they're often called feathered bullets," says Michael Begier, National Coordinator for the US Department of Agriculture (USDA) Airports Wildlife Hazards Program.