By Joe Rankin
It’s a classic story of unintended consequences. In 1890, Eugene Schieffelin, a drug manufacturer and member of the New York Zoological Society, released 60 starlings in New York’s Central Park with the hope of establishing a breeding population. Worried that the experiment wasn’t successful, he released another 40 the next year.
Schieffelin was a big Shakespeare fan and he wanted to bring to the New World all of the European birds mentioned in The Bard’s plays. (Starlings appear in Part I of Henry IV.) Schieffelin was also a member of the American Acclimatization Society, a group that advocated shifting species around the globe. It apparently seemed like a good idea at the time, and had the support of a lot of scientists. Nowadays we know that it’s not a good idea to move species from their original habitats – but now it’s too late.
Schieffelin’s starlings multiplied and multiplied and multiplied. Today there are millions of them in North America, all descended from the Central Park birds. The species, originally from Eurasia, has also, with human help, been introduced to places as diverse as the Falkland Islands and Fiji, South Africa, and Mexico.
Starlings are a poster bird for species introduction gone wrong. “The starling is undoubtedly one of the least loved birds in North America, for it . . . crowds out other species and its bothersome population growth seems to have no clear end in sight,” wrote Donald Stokes in his Guide to Bird Behavior, Vol. 1. “In these respects, Sturnus vulgaris is very similar to Homo sapiens.”
Even now, more than a century into its occupation of North America, the starling is still the worst of the “big three” imported avian invasive species, said Kevin McGowan of the Cornell Laboratory of Ornithology. The other two are the house sparrow (which Schieffelin also had a hand in introducing) and the common pigeon.
“They’re really active competitors for nest holes which are an attractive commodity. There aren’t enough holes to go around,” McGowan said.
It’s hard to get a grip on the starling population. BirdLife International estimates more than 310 million birds exist around the globe. Partners in Flight puts the worldwide population at 150 million, with 45 million in the U.S. and 12 million in Canada. One U.S. Department of Agriculture research paper published in 2007 put the U.S. population at 200 million, or a third of the global population. But even without exact numbers, we can safely assume it’s a lot.
Starlings are successful as a species because of their toughness and their personality. “Pugnacious” is the word McGowan uses to describe them. Last winter he watched a starling lay claim to his suet feeder during a blizzard and defend it against all invaders including a much-larger pileated woodpecker for an entire day.
McGowan said the starling’s attitude is matched by its physique. A starling weighs about 85 grams, even though a bird that size typically only weighs about 50 grams. “It’s solid muscle. They’re stocky and muscular, which makes them pretty effective competitors against other birds.”
Starlings are also intensely social, gathering in huge flocks at all times of the day and in every season. They swoop through the sky in flocks called murmurations, the shifting black mass looking like smoke in the wind. Starlings fascinate scientists who have spent a lot of time trying to figure out how they position themselves in such huge, constantly shifting airborne flocks without bumping into each other.
The flock mentality has made the starling an agricultural pest. A large group can swoop in and do a lot of damage to crops. The federal government spends serious money every year killing starlings and other blackbirds.
But despite their common status as a pest, starlings actually make good pets, albeit noisy ones.
“I had some friends who had one that would respond when it was called,” said McGowan. “They’re social, so when they’re raised from babies they like people and want to interact with them.”
The starling is not a sweet singer, its vocal repertoire consisting mainly of squeals, squeaks, and chortles. But it is a gifted mimic. The passage which features the starling in Henry IV, makes note of the starling’s powers of mimicry.
“They’re fascinating animals, beautiful, with iridescent feathers, and just as interesting as all get out,” McGowan added. “They do fit into the urban environment. They’ve adapted to do that.”
There is evidence now that the starling’s population explosion might have halted. The U.S. Geological Survey’s Breeding Bird Survey shows a steady decline between 1966 and 2015; BirdLife International’s starling factsheet notes a “moderate” decline in Europe. No one knows why. It could be mechanization of agriculture, the loss of grasslands in the East to regenerating forest, or the ongoing campaign of death waged against them by the Department of Agriculture. Or a combination of those or other factors.
But it isn’t likely that this avian invader will be eliminated from our landscape anytime soon. “I would never say never,” McGowan said.
Joe Rankin lives in Maine and writes about forests and nature. Illustration by Adelaide Tyrol. The Outside Story is assigned and edited by Northern Woodlands magazine, northernwoodlands.org, and sponsored by the Wellborn Ecology Fund.