The Great Grey Owl (Strix nebulosa), or great gray owl, is a large and widely distributed species of owl. It can be found in boreal forests throughout the Northern Hemisphere, both in North America and Eurasia. It is the world's largest owl in terms of length, though is surpassed in mass by the Eurasian eagle-owl. Despite its large size, the great grey owl primarily feeds on small rodents, but will also hunt squirrels, rabbits, birds, and frogs in some areas.