The Northern Harrier is one of the most widespread and easily recognized diurnal raptors in North America. Both sexes are medium-sized, slender birds with long wings, long tails and white upper tail coverts. The male is gray above, and whitish below, with black wing tips. The female is brown above and streaked below. Harriers forage by cruising low over open ground, slowly and somewhat erratically flapping and gliding, suddenly rising, stalling, turning, hovering, and dropping into the grass to seize a vole or small bird. The Northern Harrier is most commonly associated with wetlands such as marshes, muskegs, and estuaries, but also frequents dry grassland areas. It can respond to high population levels of its favorite prey, the vole, by mating polygamously.
SIZE
The Northern Harrier is a medium-sized raptor. The female is larger than the male. Lengths average 19 inches (48 centimeters) for females and 17 inches (43 centimeters) for males. Wingspans average 46 inches (116 centimeters) for females and 41 inches (103 centimeters) for males. Weights average 1.1 pounds (496 grams) for females and 0.8 pounds (346 grams) for males.
MORPHS
The Northern Harrier has no color morphs.
SPECIFIC DESCRIPTION
Adult Male - Flight
- slender hawk with long wings and tail
- gray upperparts ranging from pure gray to gray with brown mottling
- white upper tail coverts
- wings long with slightly rounded tips
- black wingtips and black tips on secondaries
- underwings mostly white with black wing tips and black tips on secondaries
- underparts white with gray upper breast band and light brown spotting on breast
and flanks
- tail mostly whitish below and gray above, with indistinctive narrow bands
Adult Female - Flight
- slim hawk with long slender wings and long tail
- whitish underparts streaked with dark brown, including the undertail coverts
- underwing shows darkish secondaries, median coverts, and axillars and light primaries with dark brown bars
- underwing linings are buffy with dark spotting
- upperparts are brown with some tawny mottling especially on lower shoulders
- vivid white upper tail coverts
- tail is brown with darker bands
Immature - Flight
- slim hawk with long slender wings and long tail
- underparts are a rich cinnamon (fall) or a washed out cinnamon (spring) including undertail coverts
- upperparts are dark brown with some rusty mottling on lower shoulder
- vivid white upper tail coverts
- underwing shows darkmedian coverts, axillars, and secondaries and whitish primaries with dark bars.
- tail is brown with darker brown bands; can show light cinnamon bands in outer tail feathers
SIMILAR SPECIES
The Northern Harrier is a very distinctive bird but under some conditions can be confused with other species. Over its open ground habitat it might be confused with a light morph Rough-legged Hawk. Both species show white around the tail. However, the Rough-legged Hawk has a black rectangle on the bend of each underwing, usually shows a fairly heavy dark belly band, and shows either a broad subterminal band or a narrower series of dark bands on its tail. The Rough-legged Hawk's tail base is usually whitish. The Northern Harrier always has a generally dark tail which may show indistinctly some dark bands, but it always has white upper tail coverts above the root of the tail.
Both the Turkey Vulture and the Northern Harrier can appear as dark birds with wings held in dihedral. The Turkey Vulture has a broad eagle-like wing that shows two tones, the dark wing linings and the silvery flight feathers. The Northern Harrier has a long slender wing displaying no such effect. Also, harriers in all plumages are much lighter on their underparts than the black Turkey Vulture and harriers show white rumps while Turkey Vultures do not.
A White-tailed Kite and a male Northern Harrier are about the same size and share similar proportions but the kite has pointed wingtips, shows a black oval at the bend of its underwings, black shoulders on its upperwings, and lacks the black bar on the secondaries and the white rump of the harrier.
The Red-shouldered Hawk is similar to the female Northern Harrier. It may show white barring on its uppertail coverts but nothing like the unbroken white upper tail coverts of a harrier. The Red-shouldered Hawk has shorter, broader wings and in both adult and immature plumages shows a much broader, more contrasty tail - black with thin white bands in the adult and gray with thin white bands in the immature. The Red-shouldered Hawk also shows white, or tawny, crescent "window" in the primary feathers. The harrier's tail is long, usually folded and is silvery gray with medium dark bands.
Swainson's Hawks also often show a white crescent on the rump, but it is nothing like the broad unbroken white rump patch of a harrier. The immature Northern Goshawk is similar to the adult female Northern Harrier but the former lacks the dark secondaries and axillars of the harrier.
OTHER NAMES
The North American race of the Northern Harrier was formerly known as the "Marsh Hawk." Other names include the "Blue Hawk", the "Frog Hawk", the "Mouse Hawk", and the "White-rumped Harrier." The Old World race is commonly known as the "Hen Harrier" and the South American race is known as the "Cinereous Harrier."
ETYMOLOGY
The scientific name Circus cyaneus translates into "circle "(Circus from the Greek kirkos) and "dark blue" (cyaneus from the Greek kyaneous) referring first to flying in circles and then to the color of the male's upperparts.
MYTHOLOGY
In various European cultures from the time of Pliny ( ~A.D. 50) harriers have been considered omens of good luck, either in general or specifically for marriage and financial affairs.
