The Northern Harrier (Circus hudsonius) is a slender, long-winged hawk commonly seen gliding just above marshes, fields, and grasslands. Unlike most hawks, it has an owl-like facial disc that helps it detect small animals by sound. Its low, buoyant flight, V-shaped wings, and prominent white rump patch make it one of North America’s easiest raptors to recognize in flight.
Northern Harrier Identification
Northern Harriers are medium-sized raptors with long, fairly broad wings, a long rounded tail, and a small hooked bill. They are smaller and more lightly built than Red-tailed Hawks but larger than Sharp-shinned Hawks.
Identification Features
Look for these key features:
- Long wings and a long tail
- Wings held in a shallow V while gliding
- Large white patch at the base of the tail
- Flat, owl-like facial disc
- Low, wavering flight over open ground
- Small head and slender body
- Frequent side-to-side turns while hunting
Both sexes display the white rump patch, which is often the best field mark when the bird is moving away.
Northern Harrier Size
Male and female Northern Harriers differ noticeably in weight, with females generally being larger.
| Measurement | Approximate size |
| Length | 18.1–19.7 inches |
| Wingspan | 40.2–46.5 inches |
| Weight | 10.6–26.5 ounces |
Their wingspan may exceed three feet, but their lightweight body allows them to fly slowly and remain close to the ground while hunting.
Male vs. Female Northern Harrier
Male and female Northern Harriers look so different that inexperienced observers may think they are separate species.
Male Northern Harrier
An adult male has pale gray upperparts, whitish underparts, black wingtips, and a dark trailing edge along each wing. His tail is pale with several dark horizontal bands.
The adult male is often called the Gray Ghost because his pale plumage can make him appear ghostlike as he silently glides over winter fields and marshes.
Female Northern Harrier
An adult female is considerably browner. She has dark-brown upperparts, a pale underside covered with brown streaks, and a long barred tail.
The female’s brown plumage provides camouflage while she sits on her ground nest among grasses, reeds, or wetland vegetation. Females are also substantially heavier than males.
| Feature | Adult male | Adult female |
| Upperparts | Pale gray | Dark brown |
| Underparts | Mostly white | Pale with brown streaks |
| Wingtips | Black | Dark and barred |
| Body size | Smaller | Larger |
| Common nickname | Gray Ghost | Ringtail |
What Does a Juvenile Northern Harrier Look Like?
Juvenile Northern Harriers resemble adult females but normally have warmer, richer colors. Their upperparts are dark brown, while the chest and belly are buff, cinnamon, or orange-brown with less streaking than an adult female.
Young birds have a dark-barred tail and the same obvious white rump patch seen in adults. Their owl-like face, long wings, and low hunting flight help distinguish them from other immature brown hawks.
Northern Harrier in Flight
A Northern Harrier usually flies only a few feet above the vegetation. It alternates slow wingbeats with buoyant glides while moving from side to side across the landscape.
Its wings are normally raised in a shallow V, called a dihedral. The bird repeatedly tilts, turns, and briefly hovers while searching for movement or listening for prey hidden below. During migration, Northern Harriers may also fly high above ridges and coastlines.
Northern Harrier From Below
From below, an adult male appears mostly pale with black wingtips and a dark trailing wing edge. Females and juveniles show brown barring across the wings and tail.
The white rump is located on the upper side of the bird, so it becomes most visible when the harrier banks, turns, or flies away.
Northern Harrier Habitat
Northern Harriers depend on large, open landscapes with low, dense vegetation. They generally avoid heavily forested areas because their hunting method requires room to fly close to the ground.
Common habitats include:
- Freshwater and brackish marshes
- Wet meadows
- Prairie grasslands
- Old agricultural fields
- Tundra
- Pastures and croplands
- Coastal dunes and estuaries
- Shrubsteppe and open floodplains
Breeding birds favor relatively undisturbed wetlands and grasslands. Western populations may nest in dry upland environments, while populations in the Midwest and Northeast more commonly use wetlands.
Northern Harrier Range
Northern Harriers occur across much of North America. They breed mainly in Alaska, Canada, the northern United States, and parts of the western United States.
Many northern birds migrate south before heavy snow covers their hunting grounds. During winter, they may be found across much of the United States, Mexico, Central America, and the Caribbean, depending on the population. Open marshes, fields, coastal areas, and wildlife refuges are productive places to search for them.
Some populations migrate long distances, while birds living in milder regions may remain near their breeding range throughout the year.
What Do Northern Harriers Eat?
Northern Harriers primarily eat small mammals, especially voles and mice. Their diet changes depending on prey availability, season, and habitat.
Common prey includes:
- Meadow voles
- Deer mice and house mice
- Shrews
- Small rabbits
- Songbirds
- Waterbirds and their young
- Reptiles
- Frogs and other amphibians
- Large insects
During winter in northern parts of their range, meadow voles may make up most of their diet. Birds become more important when small mammals are scarce.
How Northern Harriers Hunt
Northern Harriers hunt by flying slowly over open ground while watching and listening for prey. Their facial feathers direct sound toward the ears, helping them detect rodents moving beneath grass or marsh vegetation.
When a harrier locates an animal, it suddenly drops feet-first into the vegetation. It usually eats captured prey on the ground rather than carrying it to a high perch.
Northern Harrier Call
Northern Harriers are generally quieter outside the breeding season. Around a nest, however, they may produce rapid, high-pitched calls.
A threatened or alarmed bird often gives sharp kek-kek-kek notes. Males may use additional calls during courtship displays and when delivering food to females.
Northern Harrier Nesting
Unlike most North American hawks, Northern Harriers build their nests on or very close to the ground. The nest is usually concealed within dense grass, reeds, cattails, shrubs, or other wetland vegetation. Some nests are positioned over very shallow water.
Nest Construction
Both sexes may collect grasses, reeds, sticks, and other nesting material, but the female performs most of the arrangement. The finished structure is a broad platform with a softer inner cup.
The female handles most incubation and brooding. The male supplies food, sometimes passing prey to the female in midair. A male may mate with more than one female and provide food for multiple nests when habitat and prey are abundant.
Courtship Flight
Male Northern Harriers perform dramatic aerial displays sometimes called sky dances. The male climbs, dives, twists, and completes rolling movements above the breeding territory.
These acrobatic displays advertise his fitness and help establish a pair bond.
Northern Harrier vs. Similar Hawks
Several raptors may be mistaken for Northern Harriers, especially at a distance.
Northern Harrier vs. Cooper’s Hawk
A Cooper’s Hawk also has a long tail, but it has shorter, more rounded wings and normally hunts near trees or inside woodland. Northern Harriers have longer wings, a more buoyant flight, and a white rump patch.
Cooper’s Hawks commonly use quick wingbeats followed by short glides. Harriers fly more slowly and continuously sweep low across open land.
Northern Harrier vs. Red-Tailed Hawk
A Red-tailed Hawk is heavier, broader, and more likely to soar high in circles or watch from a tall perch. An adult usually has a reddish upper tail.
The Northern Harrier is slimmer, flies much closer to the ground, holds its wings in a V, and displays a white rump.
Conservation and Threats
Northern Harriers rely on extensive wetlands, grasslands, and old fields. Wetland drainage, agricultural development, urban expansion, disturbance around ground nests, and the natural reforestation of abandoned fields can reduce suitable breeding habitat.
Protecting large areas of open vegetation benefits harriers and the small mammals, birds, amphibians, and reptiles that support their diet.
FAQs
Is a Northern Harrier a Hawk?
Yes. The Northern Harrier belongs to the hawk, eagle, and kite family, Accipitridae. Its long wings, owl-like face, ground nesting, and low hunting style make it unusual among North American hawks.
Why Is the Male Called the Gray Ghost?
The adult male has pale gray-and-white plumage and flies silently over open fields. In low light, his light coloring and smooth flight can make him appear ghostlike.
Where Is the Best Place to See One?
Search open marshes, wet meadows, grasslands, agricultural fields, coastal wetlands, and wildlife refuges. Look for a slender hawk flying low with its wings held in a shallow V.
Do Northern Harriers Nest in Trees?
No. They normally build concealed nests on the ground in dense grass or marsh vegetation. Some nests may sit slightly above shallow water.
Are Northern Harriers Dangerous to Humans?
Northern Harriers generally avoid people and focus on small animals. As with any nesting bird, observers should remain at a respectful distance and avoid disturbing adults or ground nests.
