Harris's Hawk

The Harris's hawk, known scientifically as Parabuteo unicinctus, is a medium-large bird of prey with a striking appearance. It is intermediate in size between a peregrine falcon and a red-tailed hawk, with a length ranging from 46 to 59 cm and a wingspan of approximately 103 to 120 cm. The plumage is predominantly dark brown, complemented by reddish shoulders and thighs. The tail feathers are distinctive, with a white base and tip, and the legs are long and yellow, as is the cere.

Identification Tips

Adult Harris's hawks can be identified by their chestnut shoulders, wing linings, and thighs, along with their dark brown plumage. The white at the base and tip of the tail is a key feature. Females are roughly 35% larger than males, a common trait known as sexual dimorphism. The harsh vocalizations of this species are also a notable characteristic for identification.

Juvenile

Juvenile Harris's hawks are lighter in color, with buff streaking, and may initially appear quite different from adults. However, the chestnut plumage remains a consistent identifier. When in flight, the undersides of the juveniles' wings display buff coloring with brown streaking.

Subspecies

There are three subspecies of Harris's hawk:

• P. u. superior: Found in Baja California, Arizona, Sonora, and Sinaloa, this subspecies was once thought to be more blackish and larger than P. u. harrisi, but further research suggests minimal physical differences.
• P. u. harrisi: Inhabits Texas, eastern Mexico, and much of Central America.
• P. u. unicinctus: Smaller than its North American counterparts, this South American subspecies has proportionally longer tail and wings, and adults have a dark brown ventrum streaked or flecked with white.

Distribution and Habitat

The Harris's hawk resides in sparse woodlands, semi-deserts, marshes with trees, and mangrove swamps across a range from the southwestern United States to Chile, central Argentina, and Brazil. They are permanent residents, not prone to migration, and rely on scattered larger trees or other features for important perches and nest supports.

Behaviour

Harris's hawks are known for their social nature and cooperative hunting strategies, often seen in groups of two to seven. A dominance hierarchy is present within these groups, with the mature female at the top, followed by the adult male and then the young. They are also known to assist each other in nesting.

Breeding

These hawks build compact nests made of sticks, plant roots, and stems, often lined with leaves and other soft materials. The female primarily constructs the nest, where she lays two to four white to blueish-white eggs, sometimes speckled with pale brown or gray. The young are initially light buff but turn a rich brown within a week. The female may breed multiple times a year, and young may stay with their parents for up to three years to help raise subsequent broods.

Diet and Feeding

Harris's hawks primarily prey on mammals such as ground squirrels and rabbits, including the larger black-tailed jackrabbits. They also hunt birds ranging from small passerines to adult great egrets and half-grown wild turkeys. Reptiles and large insects are part of their diet as well. When hunting in groups, they can take down larger prey effectively, utilizing their strong feet, long talons, and prominent hooked beak.

Conservation Status

The Harris's hawk is currently listed as Least Concern by the IUCN. However, the wild population is experiencing a decline due to habitat loss. In some cases, these hawks have adapted to developed areas when their natural habitats are compromised.

Relationship with Humans

Falconry

Since the 1980s, Harris's hawks have become increasingly popular in falconry due to their ease of training and sociable disposition. They have been employed in various human environments, including cities and airports, to control unwanted bird populations.

In Art

The Harris's hawk was immortalized by John James Audubon in The Birds of America as the "Louisiana Hawk," a testament to its enduring appeal and significance in avian art.