Rough-legged Hawk (Buteo lagopus)

by Hugh Jennings

The Rough-legged Hawk (RLHA) is 21-22 inches long with a 56 inch wingspan. Its genus Buteo is from the Latin for falcon or hawk. The species lagopus is from Latin for hare-footed, from resemblance of feathers on legs and feet to a hare’s furry foot. This feathering to the toes (a barred pattern in adults, unbarred in juveniles) protects the thin legs, helping retain warmth in frigid weather.

This is the only soaring hawk that is common in cold climates. It has a long, white tail with dark band or bands to help identify this hawk in all plumages. The common light morph have a distinctive black rectangular patch on the wrist when viewed from below. The male has a darker chest than belly while the female has a darker belly than chest. Dark morphs have dark bodies and wing coverts with silvery barred flight feathers with a dark trailing edge.

It nests in the Arctic tundra regions north of the boreal forests. The RLHAs migrate south relatively late in the fall and north in early spring. In the winter only a few move further south than the central U.S. The RLHA is commonly seen in the Samish/Skagit Flats area in the winter.

Its breeding success on the tundra is often determined by the population of lemmings which often provide most of the food for the young. It often hunts by hovering over fields, watching for movement below. It breeds mostly on the tundra in areas having cliffs for nesting. Some breed along the northern edge of the coniferous forest. In breeding season pairs may circle together high in the air. One may perform a sky dance, alternately flapping to a high elevation and then diving steeply.

The platform nest of sticks and grasses is in open tundra or on a cliff and will have 2-6 eggs that are white with dark marks. Incubation is 28-31 days and first flight 39-45 days later. The young remain with the parents for another 3-5 weeks. The female remains with the young at first and the male brings food to the female who feeds it to the young. Later both parents hunt.

The diet is mostly rodents, lemmings and voles, and also includes many birds. Occasionally this hawk eats ground squirrels, frogs and insects.