Pacific Black Duck –Anas supercillosa Pacific Black Duck –Anas supercillosa

PACIFIC BLACK DUCKS ARE COMMONLY FOUND ON BRIBIE ISLAND IN WETLANDS, PONDS AND CREEKS. A FAMILIAR SIGHT IS MOTHER DUCK WITH BABIES WANDERING AROUND GRASSY AREAS OR SWIMMING.

Pacific Black Ducks are large dabbling ducks 41-60 cm in length and weighing .87-1.4kg. Curiously, they have been named Black Ducks, but their colour is mainly brown. They have a black crown with black and creamy lines across their faces, bright metallic green or purple speculums on the wings (visible in flight) and white patches under the wings (also visible during flight). They are similar to the introduced female Mallard to which they are related. Interbreeding often takes place between the two species when Mallards are present. Their call is a quacking sound. Both sexes are similar with the male being slightly larger. They have no teeth but instead have sharp serrated edges on their bills which helps them to filter food from the water. Feathers are waterproof and kept so by oil glands near the base of their tails. When they preen this oil is spread across all feathers, thus rendering them water-resistant. They are gregarious and are usually seen in pairs, family groups or small social groups.

They can be found almost anywhere in Australia where there is fresh water but rarely venture into salty waters. Their preference is swampy areas with lots of vegetation. Parks and gardens are frequented regularly. Other places where they live are NZ, PNG, Norfolk Island, Indonesia and throughout the Pacific region. Most of their food such as seeds, floating vegetation, crustaceans and molluscs is taken by dabbling in shallow water. Dabbling is a process where food is obtained by the birds plunging their heads underwater, upending and raising tails almost vertically, dredging through the mud for morsels and looking for aquatic plants. They also graze on grassy areas near water to find extra food. Their preferred breeding time is between June and December and takes place near water when there is sufficient food for the duration of the season. Water courtship takes place with the males preening, bobbing and wing flapping. Nests are either in tree hollows lined with down from the females’ breasts or cupshaped grass nests on the ground in the reeds or undergrowth. 8-12 whitish green eggs are laid and incubated by the female. After about 26-32 days the eggs hatch with the downy babies almost immediately able to swim, walk and pick at food. They are cared for by the females only. Males help very little in the tending and rearing process. Babies begin to fly around 58 days of age. Two broods are normally produced each season with a survival rate of only about 20%. Young birds are ready to breed at around 1 year.

An interesting fact is that they were first described in 1785 by English ornithologist, John Latham who obtained a watercolour from Joseph Banks which was painted in NZ by George Foster on Captain Cook’s second voyage.

Predators such as eels and goannas are a huge treat to eggs and ducklings.

Like humans, ducks tend to like food which is not good for them. Feeding ducks bread, biscuits and processed foods can upset their balance and can interfere with their breeding. Lettuce, spinach, small bird seed, milk thistle and worms are foods that will do them no harm.

Conservation is currently considered of the least concern, but their population has decreased due to interbreeding with the introduced Mallard Duck.