A Closer Look at Snowy Owls
Published: February 29, 2012
Despite decades of research, including by Mass Audubon, there is much that remains mysterious, even mystical, about snowy owls. No wonder Harry Potter and Hedwig the Snowie got along so famously! And in the winter of 2012, snowy owls have been migrating southward in greater numbers than usual, and across a much greater dispersal area, prompting a lot of discussion among experts and bird enthusiasts alike.
Please remember: When observing snowy owls, view them from a distance that allows them to continue their natural behavior of feeding or roosting without being dispersed.
A Blizzard of Snowies
Snowy owls migrate in fall and winter, to regions ranging from Washington State and the northern Great Plains to the Massachusetts coast.† But we’ve been witnessing an “invasion” of snowies, with the raptors showing up as far south as Arkansas, across all of the northern U.S.—and even in Hawaii.
The conventional wisdom has been that the owls migrate because of short food supplies. But scientists are beginning to look at more complex causes. That’s because research indicates that even in years when prey (primarily small rodents called lemmings) is plentiful, snowies have been known to depart in big numbers. A related theory suggests that when lemmings are abundant, owls respond by producing many young that head south.
Big on the Bay State
In Massachusetts, the owls spend winters on coastal areas that resemble their flat, treeless arctic summer home—Plum Island in Newburyport, Duxbury Beach, and Logan Airport—where they find familiar lemming cousins (voles and mice) to feed on.
Expertise and Education
Mass Audubon’s Blue Hills Trailside Museum Director Norman Smith, a snowy owl expert for more than 30 years, has banded hundreds of snowies at Logan and other places, so that we all may learn more about these remarkable creatures. Smith also participates in an international project† to fit healthy birds with small satellite transmitters that relay valuable data about their travels and other behaviors.
You Call This Cold?
With their thick layers of feathers that extend to their talons, snowy owls can thrive in temperatures of minus-40 degrees or colder. Indeed, satellite tracking devices reveal some† snowy owls fly north in winter, far above the Arctic Circle, where they feed on ducks that find small areas of open water in the pack ice.
Snowy owls, with their five-foot wingspans, are among the largest owls. Females can weigh more than six and a half pounds while the smaller males top out at about five pounds. Researchers speculate females’ size (and associated strength) may be tied to their parental responsibilities as providers and protectors.
Size AND Speed
Despite their imposing size, snowies are falcon-like in their ability to chase down and take prey in the air. They are fast and maneuverable flyers, aided by streamlined wings that are more pointed, unlike other large owls with rounded wingtips. Snowy owls have been known to snatch from the air birds ranging from great blue herons and ducks to other raptors including American kestrels, northern harriers, and short-eared owls.
To learn more about snowy owls and the research Mass Audubon is doing, visit our Snowy Owl Project.†