“To the mouse, snow means freedom from want and fear…. A rough-legged hawk comes sailing over the meadow ahead. Now he stops, hovers like a kingfisher, and then drops like a feathered bomb into the marsh. He does not rise again, so I am sure he has caught, and is now eating, some worried mouse-engineer who could not wait until night to inspect the damage to his well-ordered world. The rough-leg has no opinion why grass grows, but he is well aware that snow melts in order that hawks may again catch mice. He came down out of the Arctic in hope of thaws, for to him a thaw means freedom from want and fear.” Aldo Leopold, January Thaw-A Sand County Almanac, 1949.
Leopold’s description of a hunting Rough-legged Hawk is a near perfect description of many naturalists’ first sighting of this winter visitor. Rough-legged Hawks migrate south from their Arctic breeding grounds first arriving in Ohio between October 20 and November 10 in most years. Over the next month or so they begin to establish their wintering ranges in reclaimed strip mines of eastern Ohio, large grasslands and hayfields, and wildlife areas such as Killdeer Plains Wildlife Area in Marion County. In the larger strip mines of eastern Ohio, daily numbers can range between 5 and 20 individuals. Other areas such as Killdeer Plains and along the western Lake Erie lakefront produce up to six birds per day. Observations near the Ross-Pickaway County lines during the Kingston Christmas Bird Counts of 1974-1975 and 1975-1976 produced an incredible 72 and 87 individuals respectively.
Rough-legged Hawks are circumpolar breeders, meaning they breed in the Arctic of North America, Europe, and Asia. In the Arctic, they occupy open treeless tundra building nests on cliffs and rock outcrops. In years when the abundance food in the Arctic is high, they may extend their range to the forested Taiga region and place nests in the tops of trees and tree stumps. The nests are large and bulky, consisting of a mass of small sticks and twigs 24-36 inches across and 20-24 inches deep. Clutch sizes average 3-5 young in many years except when prey abundance is low, then they may only produce 2-3 young.
Rough-legged Hawks are part of the genus Buteo, from Latin meaning “a kind of hawk or falcon” and are closely related to our permanent resident Red-tailed Hawk, Red-shouldered Hawk and summer breeding Broad-winged Hawk. Their specific name, lagopus, is from Latin meaning “hare’s foot or hare-footed”, referencing the resemblance of their feathered legs and feet to hare’s furry foot. The feathered legs and feet are an adaption to maintain warmth in the high Arctic frigid temperatures.
Rough-legged Hawks exhibit a general bulky appearance, which would usually be perceived as a fairly powerful bird. They are very strong fliers, and even display a great degree of agility when hunting. Their feet, however, are considered weak and are adapted for catching the smaller prey such as mice, lemmings, pocket gophers and larger insects found in their tundra habitat. They have been observed occasionally feeding on carrion.
On their Ohio wintering grounds, they mainly prey on meadow voles and other mice and occasionally rabbits. Hunting Rough-legged Hawks are wonderful to watch. When perched they are usually found on the highest limb, even tip-top of a tree or shrub, poised in a very erect posture. This is a good field characteristic as Red-tailed Hawk often perch lower in a tree or tree line. On the wing, their flight is slow, graceful and leisurely as they drift across an open field. They often quarter the ground back and forth like a Marsh Hawk (Northern Harrier) hunting closer to the ground. They frequently hang in the air, hovering, by rapid vibration of the wings turning their head from side to side while looking down. From this hovering flight position, they drop towards the ground pursuing prey. Oftentimes, they will pull back up into the air, reposition and then partially close their wings drop straight to ground to pounce on a mouse or vole.
Rough-legged Hawks have few predators. They are considered to be very tame hawks, which historically led to many being shot on their wintering grounds in the United States by gunners and sport shooters in the late 1800’s. Their large size, leisurely flight and general unsuspicious character made them very easy targets even for the untrained shooter. Noted Ornithologist William Brewster described shooters systematically taking up to 20 birds per day during fall migrations for over 15 years along Connecticut migratory routes in the 1870’s and 1880’s. This practice was eventually discontinued in 1890 largely as a result of fewer birds as targets.
Rough-legged Hawks display different plumages (left to right): buffy, melanistic, light.
The plumage variations of the Rough-legged Hawk place it as possibly our most attractive and striking of our hawks. Basic field marks include a white rump when viewed from above, a large black band across the upper belly, black patches near the wrist in the white underwing surfaces and black-wing tips; plumages can range from very light to intermediate to a black “melanistic phase”. In Ohio, black Rough-legged Hawks can represent between ten and twenty-five percent of Ohio’s winter population. During flight years these melanistic birds may outnumber the lighter phased individuals. Plumages also differ between adults and juveniles and differ slightly for males and females. When in doubt of their identification, always fall back on the basic field marks.
Rough-legged Hawks are generally found in association with other grassland birds of prey. Areas that support them will also likely produce Northern Harriers (Marsh Hawks), American Kestrels and Red-tailed Hawks. Visiting these areas during late afternoon, dusk, and dawn may also reward you with Short-eared Owls. Many of these birds are best seen in or near your vehicle, so it provides a great activity for many of us on those colder, blue sky winter days. Checking reclaimed strip mines, grasslands, pastures and wildlife areas, such as Killdeer Plains in Marion County, should provide you the opportunity to observe this winter visitor from the far north.
John Watts is a retired Resource Manager, Columbus Metro Parks, and a member of the Ohio Natural Areas and Preserves Association (ONAPA) Board Advisory Committee.
References:
Bent, Arthur Cleveland. 1964. Life Histories of North American Birds of Prey, Part One. Dover Publications Inc., New York. 244p + plates. pp. 269-284.
Ferguson-Lees, James and David A. Christie. 2001. Raptors of the World. Houghton Mifflin. Boston & New York. pp. 704-710.
Leopold, Aldo. 1966. A Sand County Almanac. Oxford University Press. New York.
Peterjohn, Bruce G. 2001. Birds of Ohio. The Wooster Book Company. Wooster, Ohio. pp. 127-128.
Terres, John K. 1980. The Audubon Society Encyclopedia of North American Birds. Alford Knopf. New York.