Snowy owls — large, fluffy, white birds typically found in the Arctic and rarely seen south of the Great Lakes — have swooped down upon the eastern United States in greater numbers than at any time in at least 50 years, one bird expert says. The owls have been spotted as far south as Bermuda, the Carolinas and Missouri, according to news reports.
This migration of snowy owls southward is called an irruption, and this is the "largest of its kind in recent memory," said Kevin McGowan, a bird expert at the Cornell Laboratory of Ornithology at Cornell University.
Snowy owls — the same species as Hedwig, Harry Potter's fictional letter-carrying bird — are magnificent to behold, standing 3 feet (1 meter) tall and sporting a 5-foot (1.5 m) wingspan. "Snowy owls are an Arctic bird adapted to live at the top of the world, and they usually spend the winter up there," as well as the summer, McGowan told LiveScience's OurAmazingPlanet. (Whooo's in There? Amazing Images of Owls)
But why are these birds showing up in such large numbers in the Midwest and eastern United States? Typically, such winter migrations take place when the owls' food — mainly rodents, such as lemming — are unavailable. Although nobody knows yet why there are so many snowy owls showing up this year, it could be due to a crash in these lemming populations, or because the rodents are more difficult to hunt when there is more snow on the ground, McGowan said. In addition, more snowy owls may have been born this year compared to in other years, leading to more competition for finite food resources, he said. But scientists likely won't know for a while what factor or factors are behind the large irruption this year.
As for why they're going to the places they've been seen, scientists note that snowy owls are attracted to large, open plains like those found in the Arctic. "They were hatched 1,000 miles from any tree," McGowan said. For this reason, they often end up in coastal plains or at airports, where they can cause problems. This month alone, five airplanes have struck or been hit by snowy owls in the New York City region, according to the Port Authority of New York and New Jersey.