Swamp Harrier

The swamp harrier (Circus approximans), also known as the Australasian marsh harrier, Australasian harrier or swamp-hawk, is a large, slim bird of prey widely distributed across Australasia. In New Zealand it is also known as the harrier hawk or by the Māori name . It arrived in New Zealand within the last 700 years, replacing the larger species, the extinct New Zealand endemic Eyles's harrier. The swamp harrier belongs to the sub-family Circinae and genus Circus, which are represented worldwide, except Antarctica. The sub-family and genus are derived from the characteristic behaviour of circling flight during courtship and hawking. Description The swamp harrier is largely dark brown, becoming lighter with age, and has a distinct white rump. It hunts by flying slowly, low to the ground, on upswept wings. The body length is , and the wingspan is . The recorded weights of adults range from . Females are significantly larger than the males. In New Zealand, 54 males averaged and 66 females averaged . Going on mean weights and linear measurements, the swamp harrier may be by a slight margin the largest extant species of harrier but it is only marginally larger than some other species, like the marsh harriers and the Réunion harrier. Distribution and habitat The swamp harrier is widespread through Australasia and many islands in the south-west Pacific region, including much of Australia (except the arid region), New Zealand (where it is common in open country), Fiji, Vanuatu, New Caledonia and as stragglers on some subantarctic islands. It is usually found in wetlands and well-watered open country.