Laura Erickson's For the Birds

Owl Behavior

This winter, owls have become backyard birds for many northlanders. People living in the country may see Great Gray and Northern Hawk Owls just about anywhere. There aren’t many Snowy Owls around this year, but there has been one hanging out at the Duluth International Airport near the runway, drawing birders to the observation lounge to see it, and there’s always a chance that a Snowy Owl will turn up in any open field. Even in my own neighborhood in Duluth, Great Grays are here and there, and some people are seeing them every day. And now that winter’s deepening, tiny Boreal Owls are also urning up in backyards. Boreal Owls nest and roost in cavities, and perhaps the windows or something else about houses works like a super stimulus, appearing like an oversized cavity, in the way that some species try to incubate softballs and other objects that appear like oversized eggs. In the far north, Boreal Owls have even been found in igloos. It makes sense that they’d try hunting near bird feeders, where spilled seed may attract mice, but I get as many reports of them in yards that don’t have a feeder for blocks.

With the thick layer of ice from the ice storm earlier this month, and deep snows on top of that, mice have been few and far between, making it hard for these northern owls to eke out a living, since even the huge Great Gray feeds almost exclusively on mice and voles. Some of them have succumbed to starvation, and quite a few Great Grays have been hit by cars, so focused are they on listening for mice that they don’t even notice traffic. But even though these species really are specialists, people have noticed some of them branching out a bit. One woman in my neighborhood called me earlier this week after watching a Great Gray Owl kill a squirrel. She said the owl was ripping it apart—hawk-like, and taking a long time to finish. I mentioned this on one of the Minnesota birding listserves and got an email from one skeptical owl researcher who doesn’t believe Great Grays are capable of hunting for and eating squirrels, though I myself have seen a Great Gray twice try to catch a squirrel in my own yard.

Another woman called a rehabber simply to report that she saw a Boreal Owl in her yard kill and eat a flying squirrel. The rehabber was skeptical, since flying squirrels are pretty big for such a little owl to subdue, but in good health, Boreal Owls actually weigh half again the 70-140 grams that a northern flying squirrel weighs. Unfortunately, as they get hungrier and weaker, these small owls can be pretty evenly matched by even the smallest flying squirrel. Several years ago, a Boreal Owl spent over a week visiting a feeding station in Saginaw. One morning I arrived to find the owl actively hunting, and a flying squirrel hiding out in the hopper part of a feeder. Not long after I left, another birding group arrived, and witnessed an amazing battle. Apparently the heat or brightness of the rising sun, or the penetrating gaze of the staring owl, made the squirrel restless, and it finally made a run for it. But the owl was quicker, and grabbed it. The group watched for many minutes, not sure which would win the battle, but at long last the little owl managed to kill its prey, though it looked much the worse for wear. The squirrel was too heavy for the owl to be able to just fly off, so it flew at low altitude, making a few false starts, lugging the hapless squirrel to a basement window well. But unfortunately, crows had also been watching the scene, and before the exhausted owl could even start eating, they drew in and stole the squirrel for themselves.

This winter promises to provide us with some richly interesting owl stories. If you have any stories to share, send them to me at chickadee @lauraerickson.com, or mail them to me in care of this station. Also, if you witness any northern owl eating prey larger than mice, try to get a photograph that we could use to document the behavior.