The Blue Billed Duck of Australia, also known as Blue Bill, or Blue-billed Duck, bluebill duck, blue beak duck, or duck with blue bill (Oxyura australis), can be found in southeastern Australia, from the coast of Victoria up to north Queensland and New South Wales. It has one blue bill, making it easy to identify from other ducks.
This duck, from the Anatidae Family, lives near small ponds and rivers in forested areas or open plains where there are clumps of short grasses or shallow water to hide in during predators attacks and from bad weather like rain and winds.
There are spine-like shafts on both male and female tail feathers. Defense usually involves keeping the tail erect or flat over the water’s surface. It is also common for the male to hold his tail erect during courtship displays. Swimming and diving are made easier by their powerful feet.
In comparison with other ducks, this duck seems to sit lower in the water. Males have a bright-blue bill, glossy black head and neck, and rich chestnut back & wings during the breeding season. As the non-breeding season approaches, the head becomes glossy black, with gray speckles, while the body becomes chestnut and dark grey.
The breeding plumage of some males lasts all year round. The female’s plumage remains the same throughout her life as opposed to the male’s. Despite the National Parks and Wildlife publication describing bands of feathers rather than a single feather-tip coloration, the bird’s head, back, and wings have black feathers with a light-brown tip.
There is a dark grey-brown color to the female’s bill, and her feet are grey-brown instead of grey. Both sexes have brown iris. Although it’s paler than its father, the immature blue-billed duck’s bill is gray-green, unlike that of the adult female.
Blue billed duck scientific name
The scientific name of the blue billed duck is Oxyura australis
Range and habitat
Deep water and dense aquatic vegetation are preferred habitats for the Blue billed Ducks. There is no land component to this species, and it swims low in the water along the edges of dense cover. Whenever disturbed, it will fly, but when approached, it prefers to dive.
Blue billed duck size and weight
The blue billed duck is a small species of ducks having an average size of 35 to 45 cm (13.8 to 17.7 inches) in length, with a wingspan of around 60 cm (23.6 inches), and its weight can range between 800 to 850 g (28 to 30 oz).
Feathers and plumage
During the breeding season, adult male Blue billed ducks have a rich chestnut back. There is a dark brown color to the wings. A brown-black coloration is found at the top of the tail feathers, which are flecked with chestnut.
Chestnut also covers the underparts. A chestnut color dominates the neck, top breast, and flanks. There is a paler appearance to the lower breast, belly, and vent, flecked with brown patches.
There is a dark brown speckling on the under tail feathers. A greyish color covers the underwings. When the plumage is fresh, the head and neck of the bird are glossy black, sometimes with a chestnut tinge. The bill is bright blue and the nail is grayish. They have brown eyes. Webbed feet and legs are gray.
Males in eclipse resemble females, with darker heads and necks, and pale brown flanks.
The blue billed duck molts once a year, as all birds do. Molting is when feathers are changed or replaced and is necessary for maintaining healthy plumage. This molt starts in the breast area, then down over the head, finally spreading out to the wings and tail.
It takes about two weeks and in that time it cannot fly. You can see their new feathers coming through as they shake themselves dry after a bath. When this process is completed, they will be ready to start all over again!
Even though Blue billed ducks typically nest alone, There can be a large group of Blue Billed Ducks congregating outside of the breeding season, sometimes amounting to a thousand birds or more, with the majority of these birds being juveniles.
Foraging can be found in large, deep lakes, where they filter soft mud for food by diving deep underwater, mostly by diving deep underwater to search for aquatic vegetation and aquatic invertebrates. They walk with a penguin-like gait when they are on land, and they are usually seen on the water, feeding, swimming, or loafing around.
A cumbungi (bullrush, Typha sp.) bed or other vegetation over water is used as a nesting site in secluded, densely vegetated areas. Typha leaves are usually used to construct nests, which can be lined down thinly.
Diet and foraging
If a central area of a wetland that has dense cover is available, Blue billed Ducks may feed far from the shore during the day. During the summer, they eat buds, seeds, stems, fruits, leaves, as well as caddisflies, midges’ larvae, and dragonflies that is found on the bottom of swamps.
Sounds and vocal behavior
Blue billed ducks are mostly silent, but when males display, they utter rapid, low pitch rattling sounds, while females utter a soft, low-female whistle.
Blue billed ducks are monogamous creatures that stick together for life. Usually, Blue billed Ducks breed from August through November, but their mating and breeding season may vary.
They nest over water, among reeds or dense vegetation near the beach. Dead leaves (Typha) are used to make bowl-shaped nests. Solitary nests are built by these species, and there may be a slight down liner inside the nest. As far as nesting is concerned, the male does not participate.
Five to six eggs are laid by the female bluebill duck and the incubation period lasts around 27 days. Approximately 35 days after hatching, the young fledge.
During the months of April and May, juvenile blue beak ducks disperse to areas outside of their breeding ranges to molt.
Baby duck with blue bills is relatively independent of their parents, being able to feed themselves immediately. The female duck blue beak will protect her brood, including hatchlings from dump clutches of other females.
At 8 weeks, baby blue beak ducks are of a similar size to their parents. Within one year, most have full adult plumage. Yearlings in captivity were observed to be able to breed.
This particular species has a lifespan of up to 10 years in the wild but is known to live for 15 years or longer in captivity.
Movements and migration
The Blue billed duck is a migratory bird that primarily feeds on aquatic vegetation and invertebrates in fresh or brackish water. It is found throughout southern Asia and sub-Saharan Africa and parts of Australia, including the east coast of Tasmania.
Its natural habitat includes open wetlands, permanent lakes, reservoirs, irrigation canals, rice paddies, and ponds. During periods of drought, it may also venture into marshes and taro fields.
Occasionally it will visit slow-moving rivers where there are large patches of exposed mud. One such example is the eastern end of the Murray River near Echuca where it comes to feed on exposed areas during low river levels after summer rains.
Other Australian locations include Barham Swamp in Victoria and Lake Lonsdale at Kerang in northwestern Victoria.
Diseases and threats
The blue billed duck is a rare and beautiful creature. Threats to this bird include predators such as foxes, cats, snakes, and birds of prey; hunting; pollution; habitat loss; fishing nets; floods; drought; and disease outbreaks.
There is no significant change in the Blue billed duck population trend over the last ten years or three generations, so the population trend does not meet the thresholds (>30% decline over ten years or three generations).
There are over 10,000 mature individuals in the population, but the decline is estimated to be greater than 10% in the next ten years or three generations, there is a specific population structure, but the population is large and does not meet the thresholds for Vulnerable under the population size criterion. This is why a Least Concern rating is assigned to the species.
Conservation and management
Blue billed ducks are impacted significantly by two significant land uses. In addition to regulating wetlands through drainage, flood mitigation, and water harvesting, other factors are clearing, overgrazing, and salinization which result in the loss of vegetation. As a result, both species are capable of living in smaller habitats.
To counteract these impacts, the Department of Environment and Conservation has devised several strategies. Plans for salinity management and farm management are among those necessary to maintain sustainable water flows.