Radjah Shelduck

The Radjah Shelduck, also known as the Raja Shelduck, Black-backed Shelduck, or Burdekin Duck in Australia, is a striking species of waterfowl. Both sexes exhibit a predominantly white plumage contrasted with dark wing-tips and a unique collar of dark feathers. When in flight or with wings extended, a green speculum becomes visible, adding to their distinctive appearance.

Identification Tips

To identify the Radjah Shelduck, look for the white body with dark wingtips and collar. The green bands on the wings are a key feature, particularly noticeable in flight. The species exhibits sexual dimorphism in vocalizations rather than in plumage.

Habitat

These shelducks favor the saline environments of mangrove flats and paperbark tree swamps. They are also found in a variety of wetlands including brackish and freshwater swamps, lagoons, lakes, estuaries, river deltas, and billabongs, especially during the wet season.

Distribution

The Radjah Shelduck is native to the mangrove forests and coastlines of New Guinea and Australia, with some populations in the Moluccas of eastern Indonesia. In Australia, they are predominantly found in the tropical northern regions, extending through Queensland, the Northern Territory, and as far as the Kimberley in Western Australia.

Behaviour

These birds are typically seen in pairs or small flocks, forming long-term bonds. The males can become quite aggressive towards their mates during the rainy season. They are protected across Australian states, with penalties for harm or disturbance.

Song & Calls

The female Radjah Shelduck produces a harsh rattle, while the male emits a breathy whistle reminiscent of a sore throat.

Breeding

Pairs begin to seek nesting sites in January and February, often in hollow tree limbs near food sources. They do not use nesting materials other than their own down feathers. Egg-laying concludes by May or June, with clutch sizes ranging from 6 to 12 eggs and an incubation period of about 30 days.

Diet and Feeding

Their diet mainly consists of mollusks, insects, worms, aquatic vegetation, sedge, and algae. They forage close to their nesting sites, making habitat preservation crucial.

Conservation Status

The Radjah Shelduck is currently listed as Least Concern on the IUCN Red List, indicating a stable population without immediate threats to its survival.