Native Ducks – Mountain Duck Tadorna tadornoides,
Wood Duck Chenonetta jubata,
Tasmania is usually home to around 10 native duck species. Five species, Mountain Duck (Australian Shelducks), Wood Duck (Maned Ducks), Pacific Black Duck, Grey Teal and Chestnut Teal are persecuted by being subjected to an annual duck shooting season. These native ducks have an important role in the local ecology and must be protected for this reason, as much as for their intrinsic value.
These five native ducks all share the common features of waterfowl: long necks; flat blunt beaks; short legs with webs between three toes; and a broad elongated body. The wings are typically short and pointed, and wingbeats are generally rapid, requiring strong wing muscles.
Mountain Ducks are large black-headed ducks with chestnut breasts and white neck rings, the male having a darker chest, the female a white eye ring and base of bill. In flight they show prominent white shoulders and underwing.
Wood Ducks are perching ducks with dark brown maned heads and a greyish appearance, short bills and long legs, the female having a pale stripe above and below the eye. In flight they are the only southern Australian species with dark primaries (outer wing feathers) and white secondaries (inner wing feathers).
Pacific Black Ducks are large brownish ducks with two dark lines on a buff face and a green or purple speculum (coloured patch on wing). In flight they have a white underwing (less pronounced than Mountain Ducks).
Grey Teal are small greyish-brown ducks with pale throats. In flight they display white bars in the secondaries on both the upper and underwing. Chestnut Teal females are darker than Grey Teal and without the pale throat, the males have a bottle green head and speculum, and chestnut breast and belly. In flight they have white bars in the upper and underwing.
Ducks range in size from 35-50 cm (Chestnut Teal), up to 56-72 cm (Mountain Duck). Females of any given species are around 10% smaller than the males.
Mountain Ducks prefer wetlands and dams in southern Australia, and appear as vagrants elsewhere. They are regularly sighted in the eastern parts of Tasmania. Wood Ducks are widespread on wetlands throughout Australia, though have only recently begun regular breeding in Tasmania. In this state they tend to the north, east and the midlands. Pacific Black Ducks are a familiar resident or nomad on wetlands all over Australia, being one of the most commonly seen native ducks. They are quite widespread throughout Tasmania. Grey Teal are probably the most numerous ducks in Australia and occur throughout where conditions suit, typically inland, though they are less common in Tasmania. Chestnut Teal are abundant and widespread on Tasmanian wetlands, less common on mainland Australia, and generally found within 100km of the coast.
All species require suitable nesting and feeding areas. Mountain Ducks favour the salt marshes and brackish swamps of the coast, and are also found on mountain lakes in Tasmania and on southern highlands in summer. Wood Ducks prefer green grassy edges of dams and lagoons, having benefited by the increased number of farm dams close to short pasture, and are also known to use ornamental ponds and pools. Pacific Black Ducks are most likely to be found near fairly deep permanent fresh water with dense vegetation. Grey Teal are usually found on swamps and marshes of inland rivers. Chestnut Teal are likely to be found on brackish and saltwater lakes and estuaries of the coast.
Grey Teal, Chestnut Teal and Pacific Black Ducks are classed as ‘dabbling ducks’ that surface feed on aquatic insects, floating vegetation and seeds. They will upend in shallow waters to filter aquatic vegetation and insects from the mud. They may also graze at the water’s edge, eating fresh and dry grasses. Grey Teal and Pacific Black Ducks are also known to eat some cultivated crops such as rice and young green vegetables. Teal have a diet of around 1/3 animals and 2/3 plants.
Mountain Ducks will graze on pasture near dams and other water, or they upend in shallows to feed on aquatic invertebrates and plants. They eat a large proportion of animal food including shrimps, insects, small crustacea and molluscs. They swim well but they rarely dive, preferring instead to take their food in the shallows.
Wood Ducks are grazers. They prefer short clover and grass, young green herbs and emerging grain. They are believed to be less dependent on water than on fresh grass and herbs.
All species typically breed in spring, though environmental factors may trigger breeding at other times of year (see website for more details). Male Pacific Black Ducks give an impressive courtship display called a ‘grunt-whistle’, common to many ducks. They dip their bills quickly into the water, the upward movement creating an arc of water droplets over the head. As they do this they first whistle then grunt. They also preen and wing-flap to show off their plumage, including the speculum and pale yellow throat. The females will often take the lead in courtship and try to encourage the males to mate.
All five species nest in down-lined tree hollows, the Wood Duck exclusively. The other four species may also nest on the ground amongst grass, reeds, rocks (Chestnut Teal) or sand. The teals also like flood debris.
Clutch sizes are large and variable, anywhere from 5-20 eggs. In all cases young hatch with a fluffy cover of waterproof down that allows them to take to water almost immediately. They leave the nest shortly after hatching, with their parents leading them to water. Those hatched in trees jump from the nest and float to the ground.
Whilst Pacific Black males tend to desert soon after hatching, the
males of the other four species aid females in defending the young from
predators. Parents will protect young by distracting or confusing predators
in various ways. If disturbed they may huddle in a clump, or scatter
in all directions. At other times the adults may feign injury,
The calls of these five species vary widely (see website for more details including audio clips of calls).
Grey Teal have the impressive ability to detect distant drought-breaking or flooding rainfall more than 1000km away. These highly nomadic ducks tend to gather in large flocks to feed on the ‘blooms’ of insects that provide ample food following such rain events.
Ducks typically have two periods of moulting each year to replace old worn feathers (see website for more details).
Threats & Persecution
The most significant threats to all native waterbirds are decreasing habitat, regulation of river flows, and the effects of climate change. Draining of coastal swamps and marshes, combined with vegetation removal is causing waterbird numbers to decline markedly. River regulation is limiting flows to the lower reaches of major river systems and reduces wetland availability. Climatic effects are being seen in the extremes of drought that are causing wetlands to dry out. Most of these five species are affected, though some will utilise artificial water bodies as an alternative as natural wetlands disappear. All five of these species are considered “game” in Tasmania and are exposed to an annual recreational shooting season. Ducks are also shot under crop protection permits issued by the government (see Issues Sheet No. 3).
These threats combine causing decreasing numbers of native ducks. Annual aerial surveys of native waterbirds over south-eastern Australia have been carried out since 1983 and show a large decline in native waterbird numbers during that time.
Photos: © Alan Fletcher
Against Animal Cruelty Tasmania, Tasmanian Conservation Trust & Voiceless © 2012