The Radjah Shelduck (Tadorna radjah) is a species of shelduck more commonly known as a Burdekin Duck. This species can be found throughout coastal tropical northern Australia, from central Queensland through northern Northern Territory (including Kakadu National Park) to the Kimberley in Western Australia.
The species prefers the brackish waters of mangrove flats and paperbark tree swamps, but will visit freshwater swamps, lagoons, and billabongs further inland during the wet season.
Both sexes are almost all white, with dark wingtips and a distinctive “collar” of dark feathers. Seen from above in flight, the birds have green bands on the tops of their wings. The female has a harsh rattle and the male has a breathy, sore-throat whistle.
The Burdekin Duck is listed as a protected bird in all states of Australia and extremely harsh penalties exist for harming or even disturbing them.
The Burdekin forms long-term pair-bonds, and is usually seen in lone pairs or small flocks. During the wet season the males commonly become very irritable, and have been observed attacking their mates.
Their diet consists mainly of mollusks, insects, sedge materials and algae. Pairs start searching for nesting sites during the months of January and February. They nest close to their primary food source, often in the hollow limbs of trees, which makes habitat destruction a particular issue.
Burdekins don’t use nesting materials except for some self-supplied down feathers. Egg-laying is usually done by May or June, but depends on the extent of the wet season. The clutches range from 6 to 12 eggs. Incubation time is about 30 days.