Harriers are slender hawks with distinctive owl-like faces. This facial shape aids their sense of hearing and allows them to locate rodent prey by sound. Harriers are found throughout the world, but the only representative of this group in North America is the Northern Harrier.
Northern harrier (Circus cyaneus)
Northern Harriers, also known as Marsh Hawks, are long-winged, long-tailed birds of open terrain. They can be seen coursing low over fields, pastures and marshes in search of prey. Their buoyant, veering flight is very distinctive.
Harriers are slender birds, 18 to 23 inches in length, with wingspans of about 4 feet. Although large, they are light in weight, weighing approximately one pound. Adult male Harriers are silvery-blue with black wingtips; adult females are dark brown above and have brown streaks on their white underparts. The young (both male and female) resemble the adult females. All Harriers have a white rump patch. Their diet consists chiefly of small mammals especially meadow voles, but also includes frogs, insects, and small birds.
Unlike most hawks, Harriers nest on the ground. Their nests are built of dry grasses and small sticks, hidden among the weeds and vegetation in fields and marshes. At present, due primarily to loss of habitat, New Jersey’s breeding population is considered endangered. Some Harriers winter in the state but most will be seen during fall migration, often in large numbers along the coastline.