After breeding on Arctic cliffs and tundra hillsides in summer, Rough-legged Hawks winter throughout the Northern Hemisphere.
Open country is their ideal territory, where the small rodents they depend on are usually so plentiful that the hawks have enough to eat.
But the rodents are cyclic, with lower populations in some years, and in those winters, Rough-legs may migrate farther and be more abundant in the contiguous United States.