If you like a good whodunnit, here's one of the avian variety that just may stump you. How did European starlings become one of America's most numerous songbirds?

Wherever you live, you've undoubtedly seen them, heard them, read about them and, perhaps, even cursed them. European starlings are stocky black birds with feathers that are covered in white spots during winter that turn black and glossy in summer. They tend to show up almost everywhere, often in very large and aggressive numbers, in shade trees over houses, on lawns, in agricultural fields where they devour grain crops and, even, in airplane engines. On Oct. 4, 1960, Eastern Air Lines Flight 375 slammed into a large flock of starlings while taking off from Boston's Logan Airport, killing 62 of the 72 passengers on board.

But how, you might wonder, did they get across the Atlantic Ocean in the first place and, once in the New World, how did they become so numerous?

You can thank Shakespeare and a self-described Shakespeare fanatic by the name of Eugene Schieffelin.

A common starling sings from tree branch One Shakespeare character thought to use a starling to drive his adversary mad. (Photo: Spinus Nature Photography/Wikimedia Commons)

The merry birds of Shakespeare

Schieffelin was a late 19th century New York pharmacist and by 1877 was the chairman and driving force of the American Acclimatization Society. The group was founded in New York City in 1871 for the purpose of introducing European flora and fauna to North America. Schieffelin, by popular accounts, went a step further. He was an avid Shakespeare admirer and decided the group should introduce to North America every bird species that the Bard of Avon mentioned in his works. That would be roughly 60, give or take a species.

"It is not easy to come up with a complete list of bird species Schieffelin's American Acclimatization Society tried to introduce into the United States," said Joe DiCostanzo, a bird specialist at the American Natural History Museum. "It is not clear that a comprehensive list was ever published."

Some species which Schieffelin's group apparently did bring to America, DiCostanzo said, were the sky lark (Alauda arvensis), the nightingale (Luscinia megarhynchos), the song thrush (Turdus philomelos), the common chaffinch (Fringilla coelebs) and, notably, the European starling (Sturnus vulgaris). Shakespeare only mentioned starlings once, in Henry IV, Act 1, when Hotspur is rebelling against the king. Hotspur wants to get back at the ruler, so in the third scene Shakespeare has him fantasize about teaching a starling to torment the King by saying the name of one of his highness's enemies, Mortimer.

"Nay, I'll have a starling shall be taught to speak nothing but Mortimer, and give it to him to keep his anger still in motion."

That was all the prompting Schieffelin needed.

He imported 60 starlings to New York and on March 6, 1890, brought them from his country house to Central Park. Reportedly, other introductions of birds from Shakespeare's poems and plays had not fared well in America. So what could possibly go wrong with releasing five dozen little black birds with stubby tails in the middle of New York City on what has been described as a snowy and cold spring morning? More than 125 years and 200 million starlings later, we know the answer.

A small group of starlings on the ground The starlings Eugene Schieffelin started, or became over time, fairly aggressive and messy nesters. (Photo: Daniel Plazanet/Wikimedia Commons)

Much ado about starlings

"The starlings, or at least the ones that were brought over were, or became, quite aggressive," said Walt Koenig, a senior scientist at the Cornell Lab of Ornithology at Cornell University in Ithaca, New York. As a species, Koenig said that starlings are omnivorous, meaning they eat pretty much anything — insects, seeds and even occasionally baby birds — and are able to survive and thrive in a wide range of habitats. Schieffelin, undoubtedly, could not have imagined that the birds he released would multiply into several hundred million and become what Koenig calls "probably the single most successful introduced, or non-native, bird species in the United States, if not the world."

The starlings are cavity nesters and became very successful at competing for nesting sites with native bird species, such as bluebirds, that also nest in the cavities of trees and other places. "There are numerous reports of them usurping nests of native cavity-nesting species, unambiguously demonstrating their ability to displace a variety of species," added Koenig, who has a study site in California and has written a paper about the effects of starlings on native cavity-nesting species.

What makes starlings such a problem, he said, is that they are extremely messy nesters. "They bring in all sorts of sticks, the kids defecate all over the cavities and, generally, leave the cavities in worse shape than they found them," he said. "That makes it harder for other species to reuse the cavities later on. I think of them as 'using up' cavities in a way other species do not."

"What is more debatable," he continued, "are the demographic effects of starlings on native species. They certainly can cause native species to delay nesting, and there are studies suggesting that they have had, or are having, significant negative effects in some local cases. But, the evidence for them having driven widespread declines in any North American native bird species (based on analyses of Christmas Bird Counts and Breeding Bird Surveys) is oddly weak given the behavioral observations." This oddity, he said, is a topic that interests him and one that he may very well revisit in the near future.

[Until then, there's always time to train a starling to irritate someone you're not very fond of.]