Game Birds of the World

The radjah shelduck is a beautiful little white-headed shelduck with nearly white eyes and a blackish breast-band that interrupts its otherwise white underparts. Like other shelducks, it has iridescent green speculums, but in this species they are bordered with a black bar in front and a white bar behind. The back color varies from brown (in Australia) to black (in the East Indian population) and the sexes are essentially identical in appearance, although the female has a slightly narrower black breastband than the male. Only their voices—a querulous rattling in females and a wheezy whistle in males—serve to identify the sexes easily.

These birds are strongly monogamous and probably retain permanent pair bonds after they mature, presumably at two years of age. They breed solitarily, and at the start of the season establish and defend a territory that includes a nest site (usually a hollow tree), a foraging area, and a brood-rearing area. Little is known of this species' biology in the wild, but the birds apparently forage mostly on mollusks and other aquatic invertebrates, and may remain on their breeding territories as pairs or family groups throughout the dry non-breeding season if water conditions permit. The normal clutch-size is uncertain, as it seems to be frequently inflated by dump-nesting, but probably averages fewer than ten eggs. Incubation is believed to last about 30 days, and the young are tended by both parents.