|Australian Bush Birds|
|HOME INDEX THUMBNAILS||BACK|
|Australian Shelduck - Tadorna tadornoides|
|Pair of Australian Shelduck on a waterhole in the Derwent Valley, Tas. The female (leading) has white rings around her eye and beak with a more subdued white ring around the base of the neck. The male has a longer head and prominent white band around the lower neck. The male is a slightly different colour below the neck band.|
|Left. Shelduck dabbling with its tail in the air and neck stretching to reach food underwater.|
Right. Pair of Shelducks on land; note how the chestnut breast abruptly changes into the dark underside.
The Australian Shellduck (Tadorna tadornoides) is a mainly black bird with white and chestnut markings.
Male and female adults are approximately similar in colouring. Males have a black head and neck (often glossed green) with a broad, white ring at the base of the neck. Breast is buff but in eclipse males the breast is paler coloured (59 to 72 centimetres, span 1 to 1.3 metres). Females are slightly smaller (55 to 68 centimetres) with a white ring around the eye and around the base of the bill; the white band around the neck is thinner, sometimes not present. Females have slightly darker coloured breast.
In both sexes, the bill is black, eye dark brown, legs and feet dusky. Neck ring is less clearly defined in non-breeding birds. Rump and tail black, underside dark
Prominent white panels are visible on the wings in flight.
|Australian Shelduck - page 2|
Lives in pairs and family parties or large flocks in which pairs persist. Grazes on short green grass; in shallow water dabbles or upends to reach plants on the bottom.
They graze many grasses, clovers and herbs, as well as duck-weed, sedges, pondweed, ribbon weed and algae. Insects and molluscs are also taken. Birds on Rottnest Island in Western Australia eat brine shrimps. In western Victoria they damage cereal and vegetable crops.
Flocks rest in loose groups at the edge, or in the middle, of large water bodies. They swim strongly, often high on the water, but seldom dive except to escape danger during the moulting period when they cannot fly. Can walk fast and well.
If disturbed they rise quickly with a harsh warning call; on a small lake they leave the area entirely, on a large body of water they settle in the centre in a large raft and swim back to the former resting place later.
Seasonal movements are regular. In summer shelducks gather on large lakes to feed and moult (they cannot fly while moulting) then disperse to widespread breeding areas in autumn and winter. Some journeys are long; birds from south-east South Australia are found throughout Victoria and Tasmania after the breeding season and birds from near Canberra reach Tasmania and the south-eastern tip of South Australia.
Habitats include large shallow water; fresh, brackish, saline and tidal. Also found on farmland, pastures, stubble paddocks, young crops, irrigation areas, open woodland and occasionally at sea.
Shelducks probably pair for life. In south-eastern New South Wales they move to a breeding area in March and define breeding territories in April and May when they become pugnacious. Breeding territory may be a small pool of part of the shoreline of a large lake. The pair selects the nest site, often returning to the same nesting hole year after year. The nest is usually in a hollow limb of a tall tree, 2 to 25 metres above the ground; but may be on the ground in a rabbit hole or the floor of a cave, often far from water. Five to 15 eggs are laid; oval, cream, lustrous, 62-74 by 45-51 millimetres. The female incubates the eggs for 30 to 35 days.
While the female incubates the eggs the male establishes a separate territory where the young will be reared; this territory may be two kilometres or more from the nest and is defended against other shelducks. The female visits the male's territory during her feeding breaks from incubation. After the young hatch they are led overland to the male's territory and remain there.
Shelducks form pairs when sub-adults but do not breed until they are at least 22 months old.
|Left. Male Shelduck with a prominent white ring around the base of the neck Right. Female Australian Shelduck with a less obvious ring around the lower neck than in the male. The white patch on the bird's back is folded wing. (Mildura, Vic)|