Hen Harrier

The Hen Harrier is a slender, long-winged, long-tailed raptor of open country, showing one of the most striking examples of plumage difference between the sexes among European birds of prey.

Appearance

• Adult males: pale silvery-grey above and white below, with black wingtips and a white rump - earning the nickname 'grey ghost'.
• Adult females and juveniles ('ringtails'): streaky brown above and below with a conspicuous white rump and a banded tail.
• Owl-like facial disc aids in locating prey by sound as well as sight.
• Long wings and tail give a distinctly buoyant, floating flight.

Key field marks

• White rump patch, obvious in both sexes and a key distant identification feature
• Male: pale grey overall with black wingtips (only visible on the outer few primaries, forming a small 'dipped in ink' look)
• Female/juvenile: brown with heavy streaking and a banded tail ('ringtail')
• Low, floating, tilting flight with wings held in a shallow V, close to the ground

Similar species

• Montagu's Harrier male has grey wings but with a black bar across the secondaries and rufous streaking on the flanks, absent in Hen Harrier; female Montagu's is slimmer with narrower wings.
• Western Marsh Harrier is larger, bulkier, and browner with a heavier flight, lacking the bold white rump.
• Pallid Harrier male is very pale with a narrower black wedge on the wingtip; females are very similar to Montagu's and require careful comparison.

Habitat

Breeds on open moorland, upland heather, young conifer plantations, and rough grassland; in winter moves to lowland farmland, coastal marshes, and rough grazing land, often roosting communally on the ground.

Range

Breeds across northern and upland Europe and Asia; in North America the equivalent form is now generally treated as a separate species, the Northern Harrier (Circus hudsonius).

Migration

Northern populations are migratory, moving south to lowland Europe and around the Mediterranean for winter; some upland breeders make only short altitudinal movements to lowlands.

Behavior

Hunts by flying low and slow over open ground in a searching, quartering flight, using both sight and hearing to detect prey before dropping onto it feet-first; roosts communally on the ground, sometimes in large numbers, in winter.

Voice

Mostly silent outside the breeding season; gives a fast, chattering 'chek-chek-chek' near the nest and during the male's spectacular tumbling 'sky-dancing' display flight.

Feeding

Preys mainly on small mammals such as voles, and small to medium-sized birds, especially meadow pipits and other ground-nesting species caught by surprise low over vegetation.

Nesting & breeding

Nests on the ground, typically hidden in heather or long grass; lays 4-6 eggs; males may be polygynous, mating with more than one female, and perform dramatic aerial food-pass displays to their mates.