The Pink-eared Duck is a species of duck

Duck

Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...

 found in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

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It has a large spatulate bill like the Australasian Shoveler

Australasian Shoveler

The Australasian Shoveler is a species of dabbling duck in the genus Anas. It ranges from 46–53 cm. It lives in heavily vegetated swamps. In Australia it is protected under the National Parks and Wildlife Act, 1974...

, but is smaller at 38–40 cm length. Its brown back and crown, black and white barred sides and black eye patches on its otherwise white face make this bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 unmistakable. Juveniles are slightly duller, but otherwise all plumages are similar. Its vernacular name refers to a pink spot in the corner formed by the black head pattern; it is only noticeable at close distance however, making the seldom-used Australian name of Zebra Duck more appropriate.

Taxonomy and systematics

It is the only living member of the genus Malacorhynchus; a closely related, but slightly larger extinct form from New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 was described as Scarlett's Duck

Scarlett's Duck

Scarlett's Duck is an extinct duck species from New Zealand which was closely related to the Australian Pink-eared Duck . The scientific name commemorates the late New Zealand ornithologist and palaeontologist Ron Scarlett who discovered the holotype in 1941...

 (Malacorhynchus scarletti). This peculiar duck may be most closely related to the shelducks

Tadorninae

The Tadorninae is the shelduck-sheldgoose subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans....

 but its relationships are enigmatic. It may be closer to the Musk Duck

Musk Duck

The Musk Duck is a highly aquatic, stiff-tailed duck native to southern Australia. It is the only living member of the genus Biziura. An extinct relative, the New Zealand Musk Duck or de Lautour's Duck , once occurred on New Zealand, but is only known from prehistoric subfossil bones...

 and the stiff-tails (Sraml et al. 1996) and, formerly placed in the paraphyletic "perching duck

Perching duck

The perching ducks were previously treated as a small group of ducks in the duck, goose and swan family Anatidae, grouped together on the basis of their readiness to perch high in trees...

s" it is in any case not close to the dabbling ducks.

The Pink-eared Duck was reportedly known as the New Holland Duck by early colonists in Western Australia.

Distribution

Widely distributed throughout Australia and highly mobile, these ducks can appear anywhere there is standing water, especially in dry inland regions, where annual rainfall rarely exceeds 15 inches.

Food

They are dependent on plankton

Plankton

Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

, as well as crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s, mollusks and insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s. Their bill is well designed for straining minute organisms, with pliable mandibular

Mandible

The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...

flaps that channel water in a manner that allow the ducks to filter algae and other plankton efficiently. They also feed by vortexing, in which two ducks spin about a central point with the head of one opposite the tail of the other, concentrating food in a gyrating water column.

Breeding

Nesting is stimulated by the drying and filling of pools that promote increased levels of organic material. In good years, large numbers of Pink-eared ducks concentrate in shallow flood plains. However, when conditions do not meet specifications, reproduction may be completely curtailed.