The Harris Hawk (Parabuteo unicinctus) is a bird of prey found from southwestern USA south to Chile and central Argentina. There are three subspecies: P. u. superior from Baja California, Arizona, Sonora, and Sinaloa, P. u. harrisi from Texas, eastern Mexico, and much of Central America, and P. u. unicinctus from South America. Its habitat is sparse woodland and semi-desert, marshes (with some trees) in some parts of its range, and mangrove swamps in South America. The Harris Hawk is a permanent resident and does not migrate. This species was formerly known as the Bay-winged Hawk or Dusky Hawk.
The adult is anywhere from 18 to 30 inches in length and generally has a wingspan of 43 inches. In the United States, the male averages 25 ounces, while the female averages 36 ounces. The plumage is dark brown with chestnut colored shoulders, wing linings, and thighs. The tail tip is white. The legs are long and yellow. The young are similar to adults but are more streaked. In flight the undersides of the wings are beige with brown streaking. The vocalizations are very harsh.
The Harris Hawk nests in small trees, shrubby growth, or cacti. Nests are made of sticks, plant roots, and stems, and are often lined with leaves, moss, bark and plant roots. The female does most of the nest building. 2 to 4 white to bluish-white eggs are laid. . Often, there will be three adults attending one nest: two males and a female, though the female does most of the incubating. The eggs hatch in 31 to 36 days. The new hatchlings are light tan and turn a rich brown color in five to six days. They begin to explore outside the nest after 38 days and fledge at 45 to 50 days. The female sometimes may breed two or three times in one year. The young may stay with their parents for up to three years and help raise future broods.
The diet of the Harris Hawk consists of small creatures including birds, lizards, mammals, and large insects. Larger prey, such as jackrabbits, are can also be taken as this bird will hunt in groups of 2 to 6 individuals. This is an adaptation to the desert climate in which it thrives. In one particular hunting technique, a small group flies ahead and scouts, then another group member flies ahead and scouts, and this will continue until prey is captured. Another technique is for the group to surround the prey and one bird flushes it out.
The wild Harris Hawk population is declining due to habitat loss; however, under some circumstances, Harris’s Hawks have been known to move into developed areas. Since about 1980, Harris Hawks have been increasingly used in falconry and are now the most popular hawks in the West (outside of Asia) for that purpose, as they are the easiest to train and the most social.
John James Audubon gave this bird its English name in honor of his ornithological companion, financial supporter, and friend Edward Harris.