Swamp Harrier

Circus approximans

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 kāhu. Its arrival in New Zealand happened recently within the last 700 years, replacing its extinct larger New Zealand endemic sister species 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 behavior of circling flight during courtship and hawking.