Swamp harrier

The swamp harrier, also known as the Australasian marsh harrier, is a large bird of prey that roams across Australasia. In New Zealand, it is commonly referred to as the harrier hawk or "kāhu" in Māori. This species arrived in New Zealand around 700 years ago, succeeding the now-extinct Eyles's harrier. It belongs to the sub-family Circinae and the genus Circus, noted for its graceful circling flight during courtship and hunting.

Sporting dark brown feathers and a distinctive white rump, the swamp harrier boasts an impressive wingspan of 120 to 145 cm and a length of about 50 to 58 cm. It hunts by gliding slowly and close to the ground, maintaining a keen eye for prey. This bird is widespread across Australasia, including Australia, New Zealand, Fiji, Vanuatu, and New Caledonia, and prefers wetlands and open countryside.

Despite its prowess, the harrier faces threats from Australian magpies, masked lapwings, and European starlings. Its diet is diverse, comprising ground and water birds, small mammals, reptiles, frogs, and fish. In winter, carrion becomes a major part of its diet. The swamp harrier typically nests on the ground, often selecting swamps or dense vegetation, and lays between two to seven eggs per clutch.

In New Zealand, the swamp harrier is a common sight in open farmland and is sometimes used in falconry, particularly for hunting pukeko and young rabbits. The species has adapted well to European settlement and is well-known for its distinctive hunting behavior and habitat preferences in the region.