Marsh Harrier

Circus aeruginosus



This is an elegant raptor, similar in size to the Buzzard but a little more slender; it's the largest European Harrier. Its wings are lengthy and wide, its legs and tail are long; the sexes are dissimilar. Male birds are reddish-brown with a blue-grey head that's streaked with dark brown. The tail is grey and the wings are a combination of three colours – brown with black tips and big grey patches. The female is larger and is mostly dark brown; she has a pale head, chin and leading edge on the wings, and her tail is red-tinged at close range. Juvenile birds are similar to females but they usually don't have the pale marks on wings, nor the pale head.


Most commonly found in wetlands with an abundance of reedbeds and marshes. It usually breeds in the reedbeds, but recently has expanded habitat to include arable fields. Most birds of the region breed in eastern Britain, particularly in East Anglia and Kent.


Often seen soaring over the ground slowly and at a consistent height, until it stalls and drops to attack prey; wings are usually in a V-shape. Courtship includes aerial displays of rhythmic flight, the passing of food from male to female, and the female endures mock attacks from the male.


Relies on animals that live near wetlands, primarily small birds and mammals (rabbits in particular).


Nesting begins in April, when the female creates a nest amidst thick vegetation, and the male makes a 'fake' nest on a nearby platform. Males may be bigamous. Female lays 4 or 5 eggs at 2-3 day intervals, and the male brings her food. Each egg takes 31-38 days to hatch, so the age of the young varies; young can fly at 35-40 days and the female stays with them for 15-25 days after that.


A small number of birds stay in the UK for the whole winter, but most breeding birds head towards North and West Africa and return to the region by April. Breeding numbers have increased steeply since 1970 when there were just 2 or 3 females; recent numbers are approximately 400.

Observation Tips

Due to its habitat and nature, this bird is best observed when in flight. East Anglian wetland reserves in spring may also provide opportunities, as well as Titchwell and Minsmere.


Displaying birds may have a whining call: kweooo.
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