Northern Harrier

Formerly known as the “Marsh Hawk,” the Northern Harrier is a raptor of open fields and wetlands, where, unusual for a hawk, it nests on the ground. It probably benefitted from early European clearing in northern New England, but since the mid-1900s has been largely restricted to areas in Coos County. Up to 10 pairs now breed in the state each summer, roughly half as many as in the 1980s, and nesting south of the White Mountains is extremely rare. They are threatened primarily by loss of habitat, which can result from development, changes in agricultural practices, and natural succession.

If you happen to be in harrier habitat in May, watch for their “sky dance,” a mating display in which the male makes a series of looping flights and is sometimes joined by the female. If the pair sticks around to nest, they will lay 4-6 eggs which the female will incubate for a month. The young hide in dense grass or shrubs and are near-impossible to detect until they fledge in August. This is the best time to confirm harrier nesting, since the chicks are now larger, more vocal, and apt to fly around begging their parents for food.

Harriers tend to hunt low over fields and marshes, using both sight and hearing to detect prey in the tall grass. Small rodents are an important part of the diet, especially in winter, but harriers also eat many birds, snakes, and frogs. Like owls, they have prominent feathered facial disks that serve to funnel sound to their ears and assist in locating prey under dense cover. Outside the nesting season, your best chance to see a harrier in New Hampshire is during migration. Birds primarily move along the coast and major river valleys and are also frequently tallied from hawk migration stations. By December, they are rare in the state except for occasional sightings from coastal marshes, where birds likely move freely among Maine, NH, and Massachusetts.