- Appearance: owl-like face; long, rounded tail with white band; small, sharply hooked beak; yellow legs with large talons, broad wings
- Males have gray heads and backs, black-tipped wings, white undersides, and black bands along wings and tail while females have brown heads and backs, white undersides streaked with brown, and brown bands along wings and tail
- Formerly called “marsh harrier,” males sometimes known as “gray ghosts”
- Males have gray heads and backs, black-tipped wings, white undersides, and black bands along wings and tail while females have brown heads and backs, white undersides streaked with brown, and brown bands along wings and tail
- Length: 18 to 20 inches (about 1.5 feet)
- Wingspan: 40 to 47 inches (about 3.5-4 feet)
- Status: common, but declining
- Large decline in mid-1900s due to DDT use, have not fully recovered
- 47% decline from 1966 to 2014, threatened by habitat loss and pesticide use
- Habitat:
- Most common in large wetlands and grasslands with low, thick vegetation
- Also inhabit deserts, coastal sand dunes, pasturelands, croplands, dry plains, old fields, open floodplains, and estuaries during winter
- Livestock overgrazing trims grass too short for harriers’ prey to hide
- When humans reforest old fields, shade cover increases, which drives away harriers’ prey and forces them to relocate
- Found year-round in Long Island (not upstate), New Jersey, Pennsylvania, Delaware, Maryland, California, and Nova Scotia (Canada), also found in midwest of United States
- Range of migratory populations extends from Alaska to Central America
- Only harrier species found in North America
- Diet:
- During breeding season eat small mammals, reptiles, amphibians, and birds
- During winter mostly feed on voles, but also eat wild mice, house mice, rats, shrews, rabbits, and songbirds
- Pesticides drive prey species away or poisons them
- Unlike other hawks, rely almost entirely on hearing to hunt
- Same hunting strategy as owls, which can explain head shape
- Fly slowly and low over ground to spot prey
- Minimal flapping, mostly soaring to silence their flight
- When prey is spotted, hovers above prey, then pounces and strikes.
- Migration:
- Known for positioning wings in “V” shape during flight
- Breed in Canada, Alaska, and northernmost United States
- Wintering populations are found in all but northernmost United States, Mexico, Cuba, Caribbean, Central America, and Colombia
- Usually migrate alone
- One of few raptors that tend to migrate over water
- Usually fly treetop level or higher, but can fly about 1,000 feet above ground
- Cruising speed is about 18 mph, top speed is about 30 mph
- Nesting:
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- Breed in freshwater and brackish marshes, lightly grazed meadows, old fields, tundra, dry prairies, drained marshlands, and riverside woodlands
- Nest on ground in solitary pairs, sometimes form small, loose colonies
- Sometimes nests are trampled by grazing livestock
- Males have one or two mates at a time
- One male can have up to five mates when food is abundant
- Either sex chooses nest site and bring materials to nest
- Male builds platform of nest, female arranges materials
- Platform is made with thick-stalked plants (cattails, alders, and willows)
- Inner lining uses grasses, sedges, and rushes
- Average brood is 4-5 dull white eggs
- “Young of the Year”
- Juveniles fledge after 30-45 days
- Remain near nest for 3-4 weeks after first flight, dependent on parents while learning to hunt
- Pounce on small, inanimate objects to hone hunting skills
- Undersides of both sexes are pale orange – fades away as they mature
- Females reach maturity after 2 years, males after 3 years
- Males and females look similar until they mature
- Average lifespan is 8 years, but oldest northern harrier was 16 years old.
