The Hen Harrier is 41-52 cm (16-20 in long with a 97-122 cm (38-48 in) wingspan. It resembles other harriers in having distinct male and female plumages. The sexes also differ in weight, with males weighing 290 to 400 g and females weighing 390 to 750 g. It is relatively long winged and long tailed, having the longest wing and tail relative to its body size of any raptor occurring in North America.
Habitat and Distribution
It breeds throughout the northern parts of the northern hemisphere in Canada and the northernmost USA, and in northern Eurasia. It migrates to more southerly areas in winter. Eurasian birds move to southern Europe and southern temperate Asia, and American breeders to the southernmost USA, Mexico, and Central America. In France, Great Britain, and the southern US, Hen Harriers may be present all year. It breeds on moorland, bogs, prairies, farmland coastal prairies, marshes, grasslands, swamps and other assorted open areas.
Hen Harriers hunt primarily small mammals, as do most harriers. Preferred prey species can include voles, cotton rats and ground squirrels. Birds are hunted with some regularity as well, especially by males.
The nest is built on the ground or on a mound of dirt or vegetation. Nests are made of sticks and are lined inside with grass and leaves. Four to eight (exceptionally 2 to 10) whitish eggs are laid. When incubating eggs, the female sits on the nest while the male hunts and brings food to her and the chicks. The eggs are incubated for 31 to 32 days.
Calls and Songs
The female gives a whistled piih-eh when receiving food from the male, and her alarm call is chit-it-it-it-it-et-it. The male calls chek-chek-chek, with a more bouncing chuk-uk-uk-uk during his display flight.