National Geographic : 1933 Jul
THE NATIONAL GEOGRAPHIC MAGAZINE AMERICAN ROUGH-LEGGED HAWK (Buteo lagopus s.johannis) From its summer home in the north, the American rough-leg comes into the United States in fall migration, often traveling in flocks. As the name indicates, the rough-legged hawks differ from our other species in having the leg feathered to the toes. The American rough-leg is large and powerfully built, but, in spite of its strength, it feeds principally on mice, lem mings in the north and meadow mice in the south being staple foods. Rabbits are eaten where they are abundant, and large insects, such as grasshoppers, are eaten occasionally. The bird is entirely harm less, as it seldom kills other birds or poultry. This hawk nests in the far north, rang ing there in open country, seldom coming into densely forested areas. The nests are composed of sticks, the cavity lined with dry grass and feathers, and are built on ledges along bluffs or are placed in trees. The same location may be used for years, and the nest grows in bulk until it is of large size. Eggs are two to five in number, with three or four making the usual set. They are pale greenish white, fading to dingy white, spotted and blotched with brown of different shades, and shell markings of lavender and gray. One brood is reared each season. FEATHER LEGGINGS KEEP OUT THE COLD The birds vary considerably in colora tion from light to dark, but may always be distinguished by the feathered legs, or tarsi. The feather growth is heavy, par ticularly in fall and winter, so that the severest cold may be withstood. In the West they remain in the Northern States during the coldest weather of winter. The note, heard mainly during the nest ing season, is a low mewing call, suggest ing the sound made by a young kitten. The American rough-leg nests from the Aleutian Islands, the Arctic coast of Alaska, and northern Quebec, south to northern Alberta and Newfoundland. In winter it is found from southern British Columbia, Colorado, and southern On tario south to southern California, Texas, and North Carolina. Closely allied races are found in Europe and Asia. FERRUGINOUS ROUGH-LEGGED HAWK (Buteo regalis) This handsome hawk, so large that it is often called an eagle, is found in regions of prairies and plains, avoiding heavy tim ber. It lives only in the western part of our continent, and in uninhabited sections still remains fairly common. However, when an increase in agriculture takes place in any part of its nesting ground, it is crowded out. In much of its range it is known as "squirrel hawk," as ground squirrels and prairie dogs form a considerable part of its food. It also eats many pocket gophers. Birds, particularly meadowlarks, are cap tured during the summer season, and an occasional grouse may be taken, but these hawks are not known to harm poultry. They also eat large snakes. They are considered beneficial because of their de struction of harmful mammals. Frequently hunting in pairs, they cap ture game that might otherwise escape. In hunting prairie dogs, the hawks rest until the animal is away from its burrow, when one gets between the prairie dog and its hole, thereby making capture an easy matter. The birds are strong and pow erful and can carry rabbits to their nests with ease. The nests are placed on cliffs, on sloping hillsides, or in trees, sometimes in locali ties difficult of access, sometimes where they can be approached without trouble. They are often occupied for years, and occasionally grow to large size, Taverner recording one about ten feet high. They are composed of sticks, those in the base being often of large size, with a lining of grass and other soft materials. The eggs are two to five and are green ish or creamy white, blotched and spotted handsomely with brown and lavender. One brood is reared each season. On their nesting grounds these hawks utter screaming calls that have been lik ened to those of eagles, and the young are said to be quite vociferous. The ferruginous rough-leg breeds from southern Alberta and Manitoba to north eastern California, New Mexico, and Kan sas. It is found in winter from California and Montana to Baja California and northern Mexico, and has been observed casually in Wisconsin and Illinois.