Northern Harrier

Northern Harrier

The Northern Harrier, also called the Marsh Hawk, is a slender, long-winged raptor of open grassland, marsh, and agricultural fields across North America, easily recognized by its low, buoyant flight with wings held in a shallow V. Males and females look strikingly different, a pronounced sexual dimorphism unusual among North American raptors.

Its owl-like facial disc, formed by stiff, sound-directing feathers around the face, reflects a hunting strategy that relies heavily on hearing prey rustling in dense grass, in addition to sight.

Identifying Northern Harrier Feathers

• Primaries/secondaries: long and fairly narrow; pale grey in males, brown in females and juveniles, both with darker barring toward the tips.
• Tail feathers: long and narrow with several evenly spaced dark bands on a grey or brown ground.
• Rump feathers: a bold, contrasting white patch above the tail, present in males, females, and juveniles alike, one of the most reliable feather-based clues for this species.
• Facial disc feathers: short, stiff feathers arranged in a disc around the face, giving an owl-like appearance useful for sound-based hunting.
• Body feathers: males are pale grey above and white below with black wingtips; females and juveniles are brown above with buffy, streaked or rufous underparts.
• The combination of a white rump feather patch with long, narrow, banded flight and tail feathers is distinctive among open-country raptors in its range.

Plumage

Adult males are pale grey above with black wingtips and white underparts, quite different from the brown, streaked females, which along with juveniles show warmer brown and rufous tones below. All ages and sexes share the bold white rump patch. Juveniles resemble females but often with a richer rufous wash below that fades over the first year. This sexual and age-related plumage difference is more pronounced in this species than in most other harriers.

Habitat & Range

Breeds across open grassland, prairie, and marshland in Canada and the northern United States, wintering across a broader area of open habitat including marshes, fields, and grassland further south into Mexico and Central America. Northern populations are migratory, while some southern populations are resident.

Behavior & Field Notes

Northern Harriers hunt low over open ground and marsh, gliding with wings held in a shallow V and relying on both sight and hearing to detect small mammals and birds hidden in vegetation. They nest on the ground in dense grass or marsh vegetation, unusual among raptors. Calls include sharp, repeated whistles near the nest. A long, narrow banded feather along with a white rump feather found in open marsh or grassland is a strong indicator of this species.