Northern Harrier

The Northern Harrier is a common raptor of open wetlands, fresh and saltwater marshes, meadows and upland grasslands. Its long tail, white rump and low relaxed flight are distinctive. In Europe and Asia it is called the Hen Harrier or Marsh Hawk. This species is widespread, breeding throughout North America and Eurasia. It is widely but locally distributed in North America (primarily south of tundra) when breeding. It winters in parts of the U.S., the pacific coast of B.C., Mexico, Central America and parts of the Caribbean.

Adult Male (spring/summer)

Dark gray hood with distinctive owl-like facial disk. All gray above except white uppertail coverts in all plumages. Tail is gray with black bands. Below, whitish with black wingtips and a black trailing edge to wing, especially on secondaries and tertials. In flight wings are raised in dihedral. Eyes are yellow.

Adult Female (spring/summer)
Dark brown head with distinct facial disk. Hooded look especially in flight. Brown above with black bands on tail and white uppertail coverts visible in flight in all plumages. Buffy underparts are heavily streaked dark brown. From below there are noticeable white bands through secondaries and the long tail shows even-width dark and light bands when spread. Eyes are yellow.

Juvenile

Similar to adult females but have rufous underparts with dark streaking on upper breast and sides. By spring, colour of underparts fades to creamy. White uppertail coverts visible. Eyes are dark brown on female juveniles and pale gray-brown on male juveniles.

General:

Slender, medium size raptor with distinctive owl-like face which often fly with wing in a dihedral. Length: 46-50cm. Wing: 102-118cm. Weight: 300-750grams.

Behaviour:

Flies low over marshes and fields while hunting with languid, heavy wing beats. Wing beats are followed by a short glide, with wings held in a strong dihedral and teetering from side to side. Drops quickly on prey in grasses or marsh. Feeds on ground.
Perches on stumps, fence posts and, occasionally, on the ground. Eats rodents, small birds, insects, and snakes.

Habitat:

Open wetlands, fresh and brackish marshes, grasslands, tundra and farmland.

Information:

The Northern Harrier is a specialized ‘mouser’ in tall vegetation. It catches prey by sound as well as sight. Its owl like facial disk of facial feathers may function to help locate sounds.
Birds may roost communally on the ground when not breeding.
Nest is a platform of sticks and grasses lined with fine materials placed above water or on a knoll on the ground. 3-9 eggs of bluish white, sometimes with dark marks, are laid.

Similar species:

Cooper’s Hawk, Rough-legged Hawk, Short-eared Owl.

Conservation Status:

Listed as Least Concern but their numbers are showing a slow decline.

Capture Rates:

An infrequent but not rare sighting at Colony Farm, the Northern Harrier uses the open grasslands of the park to hunt. Low capture rates are indicative of the infrequent visits to the banding area, size, and of the slow flapping flight near the ground allowing them to avoid mist nets, shown by a capture of a single male.

Complex Basic Strategy, absent-limited (Dec-Apr in HY/SYs), Prebasic 2 incomplete-complete (Apr-Nov in non-breeding SYs), Definitive Prebasic Molt incomplete-complete (Jun-Dec in breeding AHYs); Prealternate absent. The Preformative can include up to 50% of body feathers but is absent in most individuals. The Definitive Prebasic Molt can be incomplete in some individuals. Look also for some underwing coverts to be retained. Females average more feathers replaced than males.