The rough-legged hawk (Buteo lagopus) is a large hawk (48-60 cm tall), it is a common summer inhabitant of the mountains and the tundra of mainland NWT and the southern Arctic archipelago. Winters are spent throughout the USA. The population size probably follows a cycle similar to the lemming population cycle.

The adult plumage is variable in colours and marking but usually displays a dark patch or shield on the belly and a light tail with a distinct dark edge. A breeding pair builds a large stick nest on cliff ledges or on the ground, and may maintain several nests that are reused in subsequent years. Two or three eggs are laid in late May.

The young birds (eyasses) are fed lemmings and voles as the relatively small feet of the rough-legged hawk prevent if from capturing larger prey. The young learn to fly about 41 days after hatching.