BOB DUCHESNE

Snowy owl invasion good for birders, bad for birds

Posted Dec. 09, 2011, at 11:30 a.m.
Last modified Dec. 09, 2011, at 3:10 p.m.

It’s going to be a snowy winter. Snowy owls have invaded Maine. Already this season, Maine has welcomed more owls than a Hogwarts reunion. They started coming before Thanksgiving and show no signs of slowing down. At least three have popped up in Aroostook County. More have appeared in coastal areas and in open fields around Portland. I’m on my toes. The first snowy owl I ever saw — my lifer — was next to Bangor International Airport 23 years ago. The last one I observed was on a barn roof in Corinna in 2007.

Snowy owls are larger than our resident great horned owls. Younger birds and females have dark barring on their white feathers. Older males are almost completely white. Snowy owls span the arctic, from North America through Eurasia. Paintings of these owls have even been found in prehistoric caves in Europe. We tend to think of owls as being nocturnal, but in the land of the midnight sun, owls are sometimes daylight hunters by necessity. They require wide open spaces, sparse snow cover and prominent perches from which to spy their prey.

This year’s snowy owl invasion is good news for birders and bad news for birds. These arctic breeders come down south only if conditions are bad up north. Usually, it’s due to a boom-bust cycle in their natural prey — lemmings.

The population of lemmings varies greatly from year to year, and if there aren’t enough to sustain the owls, they are forced to wander widely. I’ve seen one at Bombay Hook National Wildlife Refuge in Delaware. Ironically, sometimes the problem is too much food. By some reports, it was a boom summer for lemmings in the arctic, which led to a lot of baby owls fledging successfully.

Now that winter is here, there are too many youngsters competing with their parents, and many are being driven to the lower 48 states. In lean winters, even the elder owls come to Maine searching for food. This winter’s phenomenon is being repeated in most of the states bordering Canada, with owl observations from Maine to Minnesota.

Birds from the far north are unaccustomed to people. They can seem quite tame and readily approachable. But if you see a snowy owl, please appreciate it from a distance. First, it’s starving. That’s why it’s here. Second, even if you’re not scaring the owl, you’re scaring its food. Field mice, voles and hares are less likely to emerge from cover when you are near. And third, attracting attention is bad for the owl. Crows may take exception to its presence and harass the owl. A famished owl has little energy left to evade a mob of angry crows.

Remember that advice if any additional northern owls visit us this winter. Two other species cross the border with some regularity. The great gray owl breeds in the deep conifer forests of Canada and a big chunk of mountain forests in the western U.S. One or two seem to materialize in Maine each winter, though they can’t be considered an annual certainty. The great gray is North America’s tallest owl, but there’s not much under all those feathers and it isn’t as powerful as snowy or great horned owls.

Our native barred owl is regularly mistaken for a great gray owl, so if you ever contact me to say you’ve seen one, I’m going to ask you two questions: what color were the eyes and did you see the bow tie? Most owls have yellow eyes, but barred owls have dark eyes. And the great gray owl has a white bow tie (or mustache) under the facial disk, just below the beak. Both field marks are distinctive, and the great gray is significantly bigger than a barred owl.

The other possible invader is a northern hawk-owl. Food scarcity can also drive this boreal forest breeder southward, though not very often. It is the most comfortable owl in daylight, hunting from perches at the tops of trees. It has a longer tail than other owls and does, indeed, resemble a hawk when perched.

Although all of these wandering owls are rare in Maine, if they find a spot they like, they can settle in for several weeks. Word spreads among birders and crowds gather to watch. Join the crowd, but please don’t crowd the bird.

Bob Duchesne serves in the Maine legislature, is president of the Penobscot Valley Chapter of Maine Audubon, created the Maine Birding Trail and is the author of the trail guidebook of the same name. He can be reached at duchesne@midmaine.com.

SEE COMMENTS →

ADVERTISEMENT | Grow your business
ADVERTISEMENT | Grow your business

Similar Articles

More in Outdoors