Broad-winged hawk

The broad-winged hawk inhabits New Jersey’s deep, deciduous forests in the spring and summer months. Arriving in mid-April to early May to breed, they generally depart in mid-September to October for migration. The broad-winged hawk is one of 5 North American birds of prey that are considered complete migrants. The continental population leaves their breeding grounds annually for Central and South America. A year-round resident population exists in the Caribbean. Broad-winged hawks are recorded annually in New Jersey during migration. They are typically seen migrating in large flocks, called “kettles” which can sometimes number into the thousands.

Broad-winged hawks prefer to nest in dense, deciduous or mixed deciduous forests. As perch hunters, the broad-winged hawk favors a canopy with small openings for foraging. They collect sticks and bark chips to build large nest bowls in large, older trees. The use of old crow and squirrel nests by breeding broad-winged hawks has been previously noted. With the fragmentation of our New Jersey forests through human development, the broad-winged hawk is left with fewer places to nest.

An opportunistic predator, the broad-winged hawk forages on amphibians, insects, mammals and juvenile birds. As a perch hunter, the broad-winged spends a large amount of time sitting quietly and scanning for prey. Adults typically hunt more after mid-morning. During the breeding season, small mammals and amphibians are the most common prey. Large insects are an important prey item during their long-distance migration.

Within one week of arrival on their breeding grounds, broad-winged adults are paired-up for the season. Three different courtship flights have been observed in which both the male and female call and respond. Broad-winged hawks are most likely monogamous in the mating season. Pair bonds have been recorded over several years. However, it is not unlikely for a bird to take on a new mate during different years.

From the end of April into mid-May in New Jersey, nest building occurs. The males and females collect sticks and line the bowl with bark, even decorating the nest with fresh greenery. Egg laying begins in May with the females laying an egg every 1-2 days. A complete clutch is typically 2 or 3 eggs. The eggs are white or light blue with brown patches. The female incubates for 30-38 days during which time the male brings her food. When the young hatch, they are helpless and covered in white down. The young fledge the nest at 41 days, but are still dependent on the adults until they reach 50-56 days of age.

Adult and juvenile broad-winged hawks both leave their breeding grounds in August. The juveniles return to breed at 2 years of age, but some juveniles may return to breed the very next year.

Currently, the broad-winged hawk is listed as a species of Special Concern in New Jersey. The reforestation of the northeastern United States has helped to increase breeding habitat for the broad-winged hawk. In areas just north of New Jersey, populations remain stable and are even considered abundant. However, deforestation and the fragmentation of forests through human development is likely contributing a strain on the broad-winged hawk population in New Jersey. With encroaching development and human activity on this typically secretive bird, it is likely that New Jersey’s breeding population is showing a decline.

After leaving their breeding grounds for the season, they also leave the protection North America provides them with. Many birds are often hunted on their wintering grounds. Band recovery on the wintering grounds has shown the serious threat of broad-winged hawks being shot on their wintering range. As if that were not enough for these birds to face after a near 4,000 mile journey, they also face the alteration, fragmentation and complete elimination of their wintering forest habitat.

Presently, much more extensive research is needed on habitat use in migration and wintering areas. Also an important consideration is the role of forest age and size in breeding success. Further reforestation of certain areas in the broad-winged hawk’s breeding grounds would be beneficial as well.