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]
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.
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.