Radjah Shelduck

Scientific name: Tadorna radjah
Family: Anatidae
Order: Anseriformes
Class: Aves

PHYSICAL CHARACTERISTICS:

Both the male and female Radjah Shelducks are similar in their black and white coloring. Their heads, necks and under parts are white. Their wings and a prominent band across their breast are black. The Radjah ducks secondary feathers are metallic green in color with white tips. Their legs, feet and bill are light pink. These shelducks have a body length of 51 to 61 cm. The wingspan is approximately twice the body length. The juveniles of this species are similar to the adults, but the white plumage is duller in color with a brown tinge on the crown and neck. Their legs, bill, and feet are whitish in color. Their iris is dark brown. The Radjah chicks have black markings and a chestnut brown cap, which stretches to the eyes. There are a pair of very distinct white spots on the inside of the wings, each side of the upper back and one on each side of the lower back. These markings are only in the chick stage and they will grow out of it when they reach the juvenile stage. The eggs of this species are creamy white in color and have an average size of 60 x 42 mm.

DISTRIBUTION and HABITAT:

The Radjah Shelducks are divided into two races; Tadorna radjah rufitergum and Tadorna radjah radjah. Tadorna radjah rufitergum, sometimes called Red-backed Radjah or Burdekin Duck, is the Australian race that is found in the coastal tropics of northern Australia. This stretches from northern Queensland across coastal the Northern Territory to Fitzroy River of Western Australia. The majority of this race is found along the coast of Northern Territory and is scarce along the Queensland coast.

Tadorna radjah radjah, sometimes referred to as Moluccan or Black-backed Rajah Shelducks, are found around the coast of New Guinea and on the Molucca Islands, on the Aru Islands, in the western Papua and on Fergusson Island. They inhabit the coastal marshes, lagoons and swamps. They prefer large areas of shallow brackish or saline water.

BEHAVIOR:

This animal is usually seen in pairs or in small flocks. They have long-term pair-bonds. During the rainy seasons flocks break up and the males become aggressive and may even attack their mates. The Radjah ducks feed by grazing in pastures or by dabbling in the water. They feed mostly at night, spend their days roosting in trees. They are relatively slow when in flight. Both of the sexes can be quite vocal, even when flying. The females call resembles a harsh rattle while the males call is a hoarse whistle.

DIET:

Their diet primarily consists of mollusks, insects, sedge materials and algae.

BREEDING AND NESTING:

Pairs start searching for nesting sites during the months of January and February. The nests are typically near the water. They nest in the hollow limbs of trees. They dont use nesting materials except for some down feathers.

The egg-laying is usually done by May or June, but it depends on the extent of the rainy season. The clutches range from 6 to 12 eggs. Incubation time is about 30 days.

There are three primary growth stages; chicks, juveniles, and adults. The chicks can be recognized by their black markings, brown cap and white spots. The juveniles are similar to the adults, but duller in color. The adults have white heads, necks and under parts. There is a prominent black band across their breast and their wings are black.

Wild Population:

The species is not globally threatened, but is unusually vulnerable to destruction from hunting, and is now rare or absent in areas of Australia. More effective protection from hunting will need to established to prevent a serious decline in the populations.