The Snowy Owl Invasion of Winter 2017
The snowy owl is coming! This giant rare owl—which breeds in the Arctic tundra—was last seen in the northern U.S. four years ago. If you missed it then, you may be in luck!
Where Do Snowy Owls Live?
These large circumpolar owls live in the Arctic in open tundra. Because it’s flat and treeless, snowy owls tend to perch right on the ground or on short posts.
Some of you may recall when thousands of snowy owls descended four years ago in winter of 2013–14. It was the largest snowy owl irruption (an influx of a species into a place they don’t usually live) that the U.S. has seen since the 1920s. In a typical winter, around 10 Snowies visit Pennsylvania, but in 2013 the state was graced by 400.
In late November 2017, snowy owls were spotted in the Northeast in Massachusetts and New Hampshire. In early December 2017, a small number appeared in the Upper Midwest. Single birds have been spotted as far south as Oklahoma, Missouri, and North Carolina. And they’re still coming—apparently, even more quickly than they did four years ago.
Why Snowy Owls Appear
Snowy owls seem to travel southward every four years. Scientists have debated the cause, some attributing the flights to starvation, unusually cold Arctic temperatures and weather, or an abundance of young hatch-year owlets.
However, Massachusetts Audubon scientist Norm Smith has banded more than 700 snowy owls since 1981 and has never had a single year where hatch-year owls showed any signs of starvation. Some owls can be classified as “morbidly fat” according to Scott Weidensaul, a Project Snowstorm researcher and distinguished author. In other words, it’s unlikely that the owls are starving.
Lemmings, a type of small rodent, are the preferred food of the snowy owl. According to Norm Smith of Mass Audubon, more snowy owls irrupt southward following a lemming boom, not bust year. High lemming birth rates lead to greater nesting success for snowy owls and the vast majority of irruptions include hatch-year owlets. In boom years for lemmings, female snowy owls are known to lay up to 13 eggs, far above the norm of 3 to 5. In years with low lemming densities, the owls do not nest. Snowy owls are very protective around the nest and will even attack wolves and men.
It’s also unlikely that the snowy owls are freezing. These birds are tough. Those that remain in the Arctic can survive temperatures 50 degrees below zero Fahrenheit. In a research project, a snowy owl was subjected to temperatures of -135°F, colder than temperatures ever recorded on the planet. The bird survived these lethal temperatures by burning calories at 5 times its normal rate. That’s a lot of lemmings! New technology has allowed researchers to fit snowy owls with satellite transmitters, which have shown that many of the owls remain in the Arctic, preying on ducks and seabirds in pools of water between Arctic sea ice.
Where Do You See Snowy Owls?
If you spot a snowy owl, it may be perched on the ground—in an open field, on an airplane runway, or even in a shopping store parking lot.
In 2013, one snowy owl was captured at Boston’s Logan Airport. Fitted with a transmitter, the owl was tracked on its spring flight northward from April 18 to June 6th near Baffin Island before returning to Logan Airport five months later.
Adult males are smaller and paler than females. The female owl will be the parent to sit on the nest and requires more coloration for camouflage and larger size for protecting her eggs. Young owls are heavily marked with black and brown streaks. Snowy owls have very thick plumage and their legs are heavily feathered to protect them from the cold.
They hunt during the day and prefer to eat lemmings, rodents, rabbits, and birds. Females attack larger prey. I have observed a snowy owl killing a great black-backed gull and at one time stealing food from a peregrine falcon sitting in a tree in Plum Island, Massachusetts.
Photos by Anne Marie Warren
Man is the primary enemy of the snowy owl. In the early 1900s, 1,000 snowy owls were shot annually in Ontario. Today, they are protected and winter mortality is usually caused by collisions with cars, utility wires and aircraft.
A snowy owl was observed swimming in Hamilton Harbor, Ontario, Canada, after being attacked by a pair of peregrine falcons and one in Wisconsin was observed hauling a common merganser back to land using a butterfly swimming stroke.
Snowy owls are very tame when they appear and allow close observation, offering great opportunities for both naturalists and photographers.
If you see a snowy owl or hear about sightings, please share with the Almanac community below!