In the early 1850s, New York City’s trees were being ravaged by the larvae of the linden moth. Faced with a tireless pest, the city imported a creature from Europe — the house sparrow — to devour them. The scheme worked, but those same sparrows also grew and propagated, spreading across North America to become a ubiquitous brown pest, eating butterflies, destroying flowers, and killing native bird species and evicting them from their nests. Ever since, the American ecosystem has been engaged in an ongoing battle against an enemy numbering some 540 million strong.

The house sparrow represents the first of two major bird infestations to strike United States in the late 19th century. After the house sparrow, humans brought in the European starling, which, unlike its brown, larvae-eating relative, was imported for reasons more appreciative than utilitarian. Both species, since first being set free in city parks in New York and elsewhere, have seen their populations balloon into the hundreds of millions, exacting untold damage to crops, structures, ecosystems, and native species.

Oddly, both the house sparrow and starling invasions have in common a man named Eugene Schieffelin, the scion of a prosperous pharmaceutical enterprise and noted bird enthusiast. In 1852, Schieffelin became one of the first people in the country to import house sparrows, intended to preserve the trees around his family’s Madison Square home. (His actions inspired a panegyric by the poet William Cullen Bryant, who wrote “A winged settler has taken his place/With Teutons and Men of the Celtic race.”) For Schieffelin, it would mark the beginning of a dubious, decades-long career introducing Old World birds to the New, culminating in the almost singlehanded introduction of a most costly (and even deadly) pest: the European starling.

Eugene Schieffelin passed many of his leisure hours as a member of New York’s clubs and societies. In 1871, the 44-year-old founded one of his own: the American Acclimatization Society. The organization sought to introduce to the New World “such foreign varieties of the animal and vegetable kingdom as may be useful or interesting.” At the time, there was little evidence available to suggest just how misguided his mission was.

The American Acclimatization Society had allies elsewhere, like in Ohio, where from 1872–1874 the Cincinnati Acclimatization Society spent $9,000 on importing songbirds — including song thrush, wagtail, and skylark — from Europe. One public release saw the birds flutter through a suburban window, producing “a cloud of beautiful plumage,” and “a melody of thanksgiving never heard before and probably never heard since.” The Portland-based Society for the Introduction of European Songbirds invested $2,000 in setting loose two lots of birds in 1889 and 1892, including some starlings.

Starling murmuration. (YouTube)

The American Acclimatization Society introduced more house sparrows to New York in 1864, which “multiplied amazingly.” Organization members also introduced chaffinches, blackbirds, titmice, Java sparrows, and pheasants to New York, to middling success. Skylarks fared slightly better in their new home, and were seen for some time in the city after their release. It is also evident from a report taken from the society’s 1877 meeting that members had already been releasing starlings in Central Park.

Yet the date generally considered the ground zero of the North American starling invasion is March 6, 1890, when Eugene Schieffelin released 60 members of the species in Central Park. In April of the following year, he imported and liberated 40 more starlings, doubling down on the environmental contribution that would become his most lasting legacy.

Most iterations of Schieffelin’s starling story place his presumptive Bardolatry front and center. Schieffelin, it is often said, introduced the starling to America as part of a larger, whimsical campaign to bring all of the birds mentioned in Shakespeare’s work to the New World. But those who have looked into the matter have taken air out of the seductive factoid. “Neither the biography, the bylaws of the Acclimatization Society, nor other contemporary sources mention any such Shakespearean project. The story is probably a later speculation,” observes author Edward Tenner. And Schieffelin’s obituary, though it references the sparrow’s purpose against pesky larvae, does not mention Shakespeare’s influence over the starlings he introduced. The best evidence we have for the Shakespearean hypothesis is the knowledge that Schieffelin, already a noted club enthusiast, founded his own society called the Friends of Shakespeare.

Shortly after Pandora’s ornithological box was opened, critics finally began speaking out against acclimatization societies and importers of foreign animals. An 1898 paper from the Department of Agriculture lambasted the house sparrow as “one of the worst of feathered pests,” dealing untold damage to crops as it spread to 42 of the country’s then 45 states. The economic cost was already considerable. Between 1887 and 1895, the states of Michigan and Illinois spent a collective $117,500 on eradicating the new bird. They remain a significant problem today — in an editorial in the New York Times, writer Peyton Marshall describes his mother’s practice of trapping house sparrows in a garbage bag and asphyxiating them on the tailpipe of their car to protect the local bluebird population.

By the time the report was written, the starling was also migrating outward from New York City, on its way to becoming its own monumental pest. By the turn of the century, the lustrous, dark, polka-dotted birds were seen regularly in New Jersey and Connecticut. By 1916, they had spread to upper New England down to Washington, D.C., reaching Oklahoma by 1929. By the 1950s, they were in the mainland 48 states, ravaging crops, eating grain, seed, and cattle feed, and seizing nesting space from native birds.

Despite the use of teddy-bear-scarecrows by homeowners in 1914 Connecticut, and electrified wire outside in the Capitol building, the starling’s campaign has scarcely slowed down. Today, there are an estimated 220 million starlings in North America, causing $800 million in agricultural damage each year.

Though individually attractive birds that fly in entrancing murmurations, the case against starlings continues to mount. The invasive birds often nest in tractors and cause fires. Not only do they eat livestock feed, posing a particular stress to small farmers, they have been found to spread E. Coli to cattle as well. They are known to fight other birds for their nests, even throwing out eggs and chicks to take over, a practice some attribute to the demise of native species like blackbirds. Governments, farmers, and businesses killed 2 million starlings in 2013, sometimes using a poison that poses its own risks to the ecosystem. Even the Audubon Society has considered whether it’s okay to hate starlings.

In 1960, a flock of starlings even brought down a jet airliner, destroying the engines and sending the plane crashing down. Sixty-two people on board were killed.

For now, it seems nearly impossible that the hundreds of millions of starlings will disappear any time soon, though the U.S. has seen its share of massive and sudden die-offs before. In the meantime, we can expect the large and singing masses of starlings to continue to influence ecosystems, and attest to the dubious legacy of an ecologically naive time and one prodigiously misinformed man, now considered “an eccentric at best, a lunatic at worst.”