The pink-eared duck (''Malacorhynchus membranaceus'') is a species of

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form t ...

found in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It has a large spatulate bill like the

Australasian shoveler The Australasian shoveler (''Spatula rhynchotis'') is a species of dabbling duck in the genus ''Spatula''. It ranges from 46 to 53 cm. It lives in heavily vegetated swamps. In Australia it is protected under the National Parks and Wildl ...

, 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 Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

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

The pink-eared duck was first described by the English ornithologist John Latham in 1801 under the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Anas membranacea''. It is the only living member of the genus ''Malacorhynchus''; a closely related, but slightly larger extinct form from

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

was described as

Scarlett's duck Scarlett's duck (''Malacorhynchus scarletti'') is an extinct duck species from New Zealand which was closely related to the Australian pink-eared duck (''Malacorhynchus membranaceus''). The scientific name commemorates the late New Zealand ornith ...

(''Malacorhynchus scarletti''). This peculiar duck may be most closely related to the shelducks but its relationships are enigmatic. It may be closer to the

musk duck The musk duck (''Biziura lobata'') 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 (''B. delautouri ...

and the stiff-tails (Sraml ''et al.'' 1996) and, formerly placed in the

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

perching duck The term perching ducks is used colloquially to mean any species of ducks distinguished by their readiness to perch high in trees Until the late 20th century, perching ducks meant ''Cairinini'', a tribe of ducks in the duck, goose and swan family ...

s"; it is in any case not close to the

dabbling duck The Anatinae are a subfamily of the family Anatidae ( swans, geese and ducks). Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a yo ...

s. This species is the only member of the order Anseriformes known to have carotenoid pigments in its feathers, in the characteristic pink "ear" spot. 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 .

Food

They are dependent on

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

, as well as

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s and

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

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

mandibular In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

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.

References

*Sraml, M.; Christidis, L.; Easteal, S.; Horn, P. & Collet, C. (1996): Molecular Relationships Within Australasian Waterfowl (Anseriformes). ''Australian Journal of Zoology'' 44(1): 47–58. (HTML abstract) *MacDonald, J. D. 1987. ''The Illustrated Dictionary of Australian Birds by Common Name.'' Reed Books, Australia. {{Taxonbar, from=Q917578 Tadorninae

pink-eared duck The pink-eared duck (''Malacorhynchus membranaceus'') is a species of duck found in Australia. It has a large spatulate bill like the Australasian shoveler, but is smaller at 38–40 cm length. Its brown back and crown, black and white barr ...

Endemic birds of Australia Birds described in 1801