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.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.