DUXBURY, Mass. -- The snowy owl seemed almost complacent, showing the confidence of a top predator whose bright yellow eyes suggested she might be sizing you up as a weaker combatant -- or perhaps a large snack.
She had been where no bird should safely be -- Logan International Airport in Boston -- and now, regal and imposing, even in brief captivity, she represented the latest of her kind to arrive in a remarkable and growing winter's wandering to the Lower 48.
Not only is the Boston area seeing the largest number of snowy owls ever recorded, they are popping up in territory far from their usual habitat near the Arctic Circle. Ecstatic bird watchers have spotted them perched atop the Chesapeake Bay Bridge and in Washington (where one made headlines for being struck by a bus), in Little Rock, Ark., and northern Florida -- even in Bermuda.
"This year's been bizarre," said Dan Haas, a birder in Maryland. "The numbers have been unprecedented. Historic."
No one is sure why so many snowies are showing up in so many places -- whether it can be attributed to more food in their Arctic habitats than usual, or climate change at the top of the world. "Think about the canary in the coal mine," said Henry Tepper, the president of Mass Audubon, "you think about the snowy owl in the Arctic."
The big birds known as Bubo scandiacus reach a height of 20 to 27 inches and have a wingspan of 54 to 66 inches. They can live more than 30 years in captivity, and have feathers that can range from mottled brown and white to pure white. They have their own movie star -- Harry Potter's Hedwig -- and Internet meme, the image of a snowy asking the impertinent question "O RLY?" as in "Oh, really?"
"It's such a charismatic bird," said David Sibley, the author and illustrator of a series of birding guides.
Some people are less happy to encounter snowy owls -- particularly, the managers of airports that the birds are drawn to. With wide open spaces and short grass, "the airports, to them, look more like the Arctic tundra than anything else," said Norman Smith, who runs the Snowy Owl Project for Mass Audubon. The Port Authority of New York and New Jersey took heated criticism in December when it shot three snowy owls. Since then, the authority has tried trapping the birds, with limited success, and harassing them away from the airport by shooting off fireworks, said Ron Marsico, a spokesman for the Port Authority.
Ornithologists and bird watchers are not sure why the birds have come so far and in such great numbers this year. In decades of study, Smith said, "what I've learned is we know very little about this bird." He suggests that the large population is the result of a bonanza of lemmings and other small rodents that snowy owls feed on, perhaps a consequence of the milder Arctic weather. That led to larger population of hatchlings that must spread farther and farther out to find territory of their own.
The lemming hypothesis does not satisfy Kevin J. McGowan, an ornithologist at Cornell. He noted that tiny transmitters placed on the owls had shown that some of the birds do a surprising thing in winter: Instead of flying to the more temperate south, they fly farther north and scout the Arctic ice pack for pools of open water populated by sea ducks and other waterfowl.
By JOHN SCHWARTZ
The New York Times