Swamp Harrier, Circus approximans Click to enlarge image
Swamp Harrier, Circus approximans Image: ronigreer

Fast Facts

  • IUCN Conservation Status
  • Classification
  • Size Range
    Body Length: 50 cm to 60 cm; Wingspan 120 cm to 145 cm

When approached by people, Swamp Harriers can get extremely startled and will abandon their nest, eggs and even downy young.


Also known as the Marsh Harrier, the Swamp Harrier is a large bird of prey with long, thin legs and a long, rounded tail. The species is mostly dark brown, with a distinct white rump. Its face mask resembles the face mask of an owl. In flight, the wings are long and broad, with five 'fingers' on the wing tips. The females are larger and have rufous underparts, whereas the males are smaller and have lighter underparts. Adult birds have yellow legs and eyes, while juvenile birds have dark brown eyes. This species flies low over water in a steady sailing flight with up-swept wings. It is also known as the Marsh Harrier.


In Australasia and the South Pacific, the Swamp Harrier is common. It is New Zealand's most common raptor.


In tropical and temperate Australia and New Zealand, the Swamp Harrier is found in terrestrial wetlands and open areas. It can be found in both fresh and salt marshes, frequently in deep swamps with emergent reeds and over open water. It is more widely distributed in New Zealand, not only in wetlands.


Swamp Harriers are partly migratory. Part of the population in Australia move north in late summer and autumn, with other individuals over-wintering in Tasmania. They may migrate in groups and sometimes roost communally (in groups) on the ground. These harriers can also disperse inland after heavy rain.

Feeding and diet

Swamp Harriers hunt for birds and eggs, large insects, frogs, reptiles and small mammals up to the size of hares or rabbits. When hunting they 'quarter', which means that they systematically search for prey by gliding low to the ground or water, then drop down on to their quarry. In New Zealand, Swamp Harriers often feed on carrion (dead animals).


Usually silent during the non-breeding season. During breeding displays, male gives high pitched descending whistle; the female call is lower pitched.

Breeding Behaviour/s

The nest of the Swamp Harrier is made of straw and grasses, hidden above the water in dense reeds in a swamp or in crops or long grasses near water. They usually nest in single pairs. The female builds the nest, incubates and broods the young, and guards the nest; while the male hunts for food. He transfers the food to the female in the air, before she feeds it to the young.

Breeding Season: In Australia, main laying period between October - December