Rough-legged Hawks are one of three hawk species in the United States with feathers all the way to their toes, an adaptation for life in cold climates.
As with most arctic birds of prey, productivity is closely tied to prey. In years with high populations of lemmings and other prey, more eggs are produced and more chicks survive to fledge. In low prey years, they may not breed.
Their plumage colors range from light to dark. The male, female, and juvenile birds have slightly different plumage patterns.
Rough-legged Hawks spend summers in the northern reaches of Alaska, Canada, Scandinavia, Russia and other arctic and subarctic regions. In the winter, they migrate southward across the United States, northern Mexico, and central Europe and Asia.
Lemmings and voles make up the bulk of their diet, but they also hunt other small mammals and birds. They hunt during the day and sometimes at dusk and dawn, pursuing prey from a perched or hovering position.
Stick nests are built high on cliffs, rocky outcrops, riverbanks on a protected ledge with a good vantage, or, more rarely, trees. The female lays 2-7 white eggs with brown markings; the number of eggs depends on the availability of prey. The eggs are incubated for 28-31 days and the young fledge 5-6 weeks later. They reach adulthood in 2 years.