the Great Gray

A trip to the land of gray skies, little light, dense spruce and tamarack bogs, and chilly temperatures in north central Minnesota gave us an opportunity to see one of the most iconic animals of the northern Boreal forest, the Great Gray Owl, in action, doing what it does best — hunting mice under the snow.

[Note added after posting: if you’re interested, read the comments below the post for more information about the Great Gray Owl hunt]

A brief glimpse of the sun at sunrise was the only time we saw it during the entire time we were in this gray landscape, where the intensity of light in the dense overcast was about 1/50th of what it would be on a sunny day.
You have to look really carefully at every snag as you drive down the snowy roads of the black spruce forest where Great Grays like to hunt. The owls blend in so well with the conifer bark, they often go unnoticed.

Great Grays are the largest (by total body length, not weight) owl in North America. Their over-sized heads with huge facial disks are essential for hearing what is going on under the snow cover.

Great Gray Owls are mouse specialists, adept at crashing through crusty or powdery snow to depths of 18 inches to snare a vole in their talons.

The arrangement of facial feathers in two parabolas collects infra-sounds of mice running through their burrows under the snow cover and reflects it to their asymmetrically placed and shaped ears. The intensity and time difference of sound arriving at their two ears allows the owls to “focus” on the direction of the sound.

They scan the landscape under their perch by moving their head back and forth to hone in on the sounds of mice under the snow from up to 100 feet away, then quickly descend to the ground to trap their prey, completely silently. The mouse never knows the owl is coming.
Despite weighing only 2.5 pounds, these owls can break through snow crust strong enough to hold a human’s weight to get at the prey hiding below. Sharp talons snare the mouse, and the owl can quickly bring it up to its head and swallow it, head first.
Their hearing is so acute, they are able to successfully capture their prey about 60% of the time. In fact, they are more successful catching voles through snow than they are at catching gophers through loose dirt in the summer.
Great Gray Owls can hunt visually as well, and can cover hundreds of feet distance with a burst of wing flaps to grab a vole or mouse off the surface of the snow, and carry it off.