Northern Harrier

The Northern Harrier, known scientifically as Circus hudsonius and colloquially as the marsh hawk or ring-tailed hawk, is a captivating bird of prey. It is distinguished by its sexual dimorphism, with males and females sporting markedly different plumages. The male Northern Harrier, sometimes referred to as the "Grey Ghost" for its ethereal appearance, is cloaked in shades of darker grey, while the female is adorned in darker and more rufous tones. This raptor is notable for its elongated wings and tail, which are proportionally the longest of any North American raptor relative to its body size.

Identification Tips

Adult males are characterized by their slate-grey plumage and can be identified by their ghostly aura as they glide through the air. Females and juveniles are browner with a streaked breast and a conspicuous white rump patch that is visible in flight. When observing these birds, look for their distinctive flight pattern, with wings held in a shallow V and a buoyant, gliding motion.

Habitat

The Northern Harrier favors open landscapes where it can soar low to the ground. Its preferred habitats include prairies, marshes, grasslands, and other open areas that provide ample hunting grounds.

Distribution

Breeding across the northern reaches of the Northern Hemisphere, this species can be found in Canada and the northernmost United States. Come winter, the Northern Harrier migrates to the American South, Mexico, and Central America, although some populations may remain year-round in the midwestern, mountain west, and north Atlantic states of the U.S.

Behaviour

This raptor is known for its polygynous mating system, where one male may mate with several females. The male defends a territory that can vary greatly in size, and the nesting site is typically on the ground or atop a mound of vegetation. The Northern Harrier is a solitary hunter, employing its acute hearing and low, contour-hugging flight to surprise prey.

Song & Calls

The female Northern Harrier emits a whistled "piih-eh" when receiving food from the male, and her alarm call is a rapid "chit-it-it-it-it-et-it." The male's call is a "chek-chek-chek," which becomes a rhythmic "chuk-uk-uk-uk" during his display flight.

Breeding

Nests are constructed on the ground or mounds, using sticks and lined with grass and leaves. Clutches typically consist of four to eight whitish eggs, which are incubated primarily by the female for about a month. The male provides food during this period and continues to assist with feeding the chicks post-hatching.

Similar Species

The Northern Harrier can be confused with other harrier species, but its long wings and tail, as well as its unique flight pattern and sexual dimorphism, usually allow for accurate identification.

Diet and Feeding

A proficient hunter, the Northern Harrier primarily preys on small mammals like voles and ground squirrels, but will also take birds, amphibians, reptiles, and insects. It occasionally hunts bats and can overpower larger prey such as rabbits and adult ducks.

Conservation status

The Northern Harrier is classified as "Least Concern" by the IUCN, with a large range and a population that is not believed to be declining at a rate that would trigger conservation alarms.

Relationship with Humans

Historically, the Northern Harrier has been viewed favorably by farmers for its role in controlling rodent populations and protecting crops. However, heavy pesticide use in the past has led to declines in harrier populations. Some Native American tribes hold the belief that sighting a hawk on one's wedding day heralds a long and happy marriage.