Broad-Winged Hawk

## Description

The broad-winged hawk (Buteo platypterus ) is a medium-sized hawk of the genus Buteo. During the summer, some subspecies are distributed over eastern North America, as far west as British Columbia and Texas; they then migrate south to winter in the Neotropics from Mexico south to southern Brazil. Other subspecies are all-year residents on Caribbean islands. As in most raptors, females are slightly larger than males. Broad-winged hawks' wings are relatively short and broad with a tapered, somewhat pointed appearance. The two types of coloration are a dark morph with fewer white areas and a light morph that is more pale overall. Although the broad-winged hawk's numbers are relatively stable, populations are declining in some parts of its breeding range because of forest fragmentation.

## Appearance

The Broad-winged hawk is a small bird of prey found in the Americas. As in most raptors, females are slightly larger than males. Broad-winged hawks' wings are relatively short and broad with a tapered, somewhat pointed appearance. Adult birds are dark brown with a white belly and chest containing horizontal barring. Their tail can be a dark grey-black with white lines along the middle, base, and tip. The young hawks have a slightly different coloring with more white and longitudinal barring instead of horizontal barring. The two types of coloration are a rare dark morph with fewer white areas and a light morph that is more pale overall.

## Distribution

Broad-winged hawks have a wide range in North America and South America, from southern Canada to southern Brazil. They breed in the northern and eastern parts of North America, and some migrate in the winter to Florida, southern Mexico, and northern South America. Some subspecies are native to the Caribbean and do not migrate. Broad-winged hawks breed in deciduous forests good for nesting and forage primarily in wetlands and meadows. In the winter, they settle in similar habitats staying in deciduous and mixed forests as well as cloud forests, and arid tropical scrub.

## Behavior

Broad-winged hawks are generally solitary and territorial birds; however, during migration, they become highly gregarious and migrating flocks can contain thousands of individuals. Broad-winged hawks are active during the day. To catch their prey, they watch from low branches, hiding in the foliage, until a target is spotted. From their roost, they do a short, fast glide to capture the prey. These birds give special attention to preparing their food for consumption, skinning frogs and snakes and plucking prey birds' feathers. Most small mammals, though, are eaten whole. They rarely drink water and are able to survive solely with the water present in their prey. Broad-winged hawks use vocalizations for communication with their mates and offspring, and in territorial displays towards intruders. Their call sounds like a very high-pitched kee-ee, almost like a whistle. When confronted with a threat, Broad-winged hawks emit an alarm call consisting of stuttered and squealing whistles.

## Diet

Broad-winged hawks are carnivores and their diet depends on the time of year. During the summer or nesting season, these birds eat small mammals, such as chipmunks, shrews, and voles, frogs, lizards, and sometimes even other nesting birds. In the winter, they feed on insects, frogs, snakes, crabs, and some small mammals.

## Reproduction

Broad-winged hawks are monogamous and pairs usually stay together more than one breeding season. They breed between April and August. To attract and court females, the males perform a courtship display flight including cartwheels, dives, and other aerial acrobatics. Birds meet in the air, hook their feet together and spiral down together. The males also compete and fight with each other for the chance to mate with a female. Both the male and female build the nest out of sticks and twigs in a deciduous tree. The female lays 1 to 4 brown-spotted eggs that weigh about 42 g (1.5 oz). The female then develops a brood patch and incubates the eggs for 28 days or longer before they hatch. The chicks hatch semialtricial; they are not able to move on their own or leave the nest but have open eyes and are covered in down feathers. While in the nest, the female gives most of the parental care, protecting and providing food for the chicks. The male may provide some food for the female and offspring, but his visits are short-lived. The chicks need around 5-6 weeks before they are able to leave the nest; however, some young, even after that time, remain in the area of the nest for several weeks more. They usually reach reproductive maturity at about two years of age.

## Population

### Population threats

The largest threat to the Broad-winged hawk is forest fragmentation, particularly within its breeding range. Other main causes of this species population decline include eggs and nestlings predation, hunting, trapping, and vehicle collisions.

### Population number

According to the What Bird resource, the total Broad-winged hawk population size is 1,800,000 individuals. According to the Hawk Mountain Sanctuary resource, the total population size of the species is around 1.5 to 2 million birds. Overall, currently, Broad-winged hawks are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.

### Ecological niche

Broad-winged hawks play an important role in local ecosystems by controlling populations of small mammals, such as rodents and rabbits. They, in turn, provide food for their predators such as raccoons, crows, porcupines, and American black bears.

## Fun Facts for Kids

Broad-winged hawks were named for their short but broad wings.

Broad-winged hawks are known for their spectacular migrations of swirling flocks. Flocks consist of more than 40 up to several thousand birds that fly at heights from 550 to 1,300 m (1,800 to 4,270 ft).

The enormous flocks of soaring Broad-winged hawks are called "kettles" and are characteristic of many hawk migration spectacles in North America, such as at Hawk Cliff in Ontario, Hawk Ridge in Minnesota, Hawk Mountain in Pennsylvania, and the River of Raptors in Veracruz.

Fall migration of Broad-winged hawks lasts for 70 days during which birds migrate about 100 km (62 mi) per day from North America, through Central America to South America without crossing saltwater.

To conserve energy during migration, Broad-winged hawks soar using thermals to carry them through their journey of 3,000-6,000 km (1,900-3,700 mi).

Broad-winged hawks sometimes use abandoned nests of crows or even squirrels.