[2] Formerly placed in the genus Tadorna, it differs markedly from other members in external morphology and mtDNA cytochrome b sequence data, suggesting its status should be reinvestigated.

To communicate, the female utters a harsh rattle while the male emits a breathy, "sore-throat" whistle.

The radjah shelduck is listed as a protected bird in all the states of Australia, and penalties are enforced for harming or disturbing them.

The species prefers the salty waters of mangrove flats and paperbark tree swamps, but will visit all manner of brackish and freshwater swamps, lagoons, lakes, estuaries, river deltas, and billabongs further inland during the wet season.

They nest close to their primary food source, often in the hollow limbs of dead or dehydrated trees, which makes habitat destruction a particular issue.