Field Marks: 23in. Unmistakable. A large white owl of the Artic, with striking yellow eyes; resident in tundra and open country. Large, rounded head without ear tufts; heavy build. Active by day as well as night. Flight strong and direct; often glides low over ground. Nests in Far North, where it feeds on lemmings and other small rodents; in irruption years, when prey is scarce, invades southern Canada and United States. Adults nearly all-white or with scattered dark bars above and below; female with more barring than male. Immature resembles adult but more heavily barred and spotted.
Range: Breeds in n. Alaska and n. Canada. Winters south to northernmost United States. Occasionally farther south in years of periodic irruptions.