Pink-eared Duck Malacorhynchus membranaceus Scientific name definitions

36–45 cm; male 290–480 g, female 272–423 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); wingspan 57–71 cm. Unmistakable . Sexes basically alike, with grey forehead and crown , white face with large dark brown eye-patch continuing as narrow stripe to nape and forming stripe on hindneck, white eyering, small pink tuft above and behind eye, white underparts broadly barred dark brown from upper breast to vent, the bars becoming broader and darker on flanks, pale chestnut undertail-coverts, barred mantle, back and wings brown finely vermiculated paler, with narrow white trailing edges to wings , white rump , dark brown uppertail-coverts, brown tail with narrow white terminal band, white underwings with pale barring on underwing-coverts and dark brown flight feathers; bill lead grey, with square tip, spatula-like shape and soft membranous flaps at tip of maxilla; legs and feet dark grey; irides brown. Female is smaller and lighter, but differences unlikely to be appreciable in field (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Juvenile duller and browner, with less barring, greyer forehead (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) and pink spot on face hardly apparent.

Australia: main centres of population in SW & SE.

An ecological specialist, exploiting temporary ponds and lakes of shallow saline or brackish waters of inland Australia. Occasionally found in more permanent, deeper waterbodies, as well as at waste stabilization ponds (2 Hamilton, A.J., Taylor, I.R. and Hepworth, G. (2002). Activity budgets of waterfowl (Anatidae) on a waste-stabilisation pond. Emu. 102(2): 171–179. Close , 3 Murray, C.G. and Hamilton, A.J. (2010). Perspectives on wastewater treatment wetlands and waterbird conservation. Journal of Applied Ecology. 47: 976–985. Close ).

Somewhat dispersive and nomadic; can be seen almost anywhere in Australia , and even in Tasmania, but only very rarely in dry inland regions; regularly reaches coastal areas, although inland wetlands of SW & SE are species strongholds (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Its distribution clearly reflects extent of flooding in each area. One record from New Zealand, at Mangere in Jun–Jul 1990 (4 Eller, G.J., Haslett, C.M. and Sibson, R.B. (1991). Pink-eared Duck at Mangere. Notornis. 38(2): 109–110. Close , 5 Gill, B.J., Bell, B.D., Chambers, G.K., Medway, D.G., Palma, R.L., Scofield, R.P., Tennyson, A.J.D. and Worthy, T.H. (2010). Checklist of the Birds of New Zealand, Norfolk and Macquarie Islands, and the Ross Dependency, Antarctica. 4th edition. Te Papa Press & Ornithological Society of New Zealand, Wellington, New Zealand. Close ).

Planktonic organisms (algae, microscopic seeds, crustaceans, molluscs, insects, etc.). Feeds mostly on surface by water and mud filtering with highly specialized bill, sometimes while walking, feeding either alone, in parallel, by spinning or vortexing (in both directions ) in pairs, trios or flocks (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); may also dabble and frequently upends, but never dives (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Study in S Victoria found that birds spent on average 38·7% of daytime feeding and 41·8% resting, with clear peaks in foraging activity around sunrise and sunset, and surface filtering (96·9%) was almost the sole foraging method, although dipping (2·1%) and surface dabbling (1%) were also employed (2 Hamilton, A.J., Taylor, I.R. and Hepworth, G. (2002). Activity budgets of waterfowl (Anatidae) on a waste-stabilisation pond. Emu. 102(2): 171–179. Close ).

Vocalizations usually described as chirruping or twittering, especially when referring to flocks in flight, with no obvious differences between the sexes; four main calls have been described, as follows: (i) a distinctive, trilling “we-we-we-we-we-we-we-ooo” that is variable in its intensity, from a soft purring to frenzied version, often rising and falling in pitch, and is commonest vocalization heard from birds in flocks; (ii) a sharp, ticking   “tu-ick”, “puik” or “tick-uk”, which is probably given in alarm; (iii) a deep nasal “gronk” or “grunk” whose context or function is unknown; and (iv) a loud trumpeted whistle, “whee-ooo”, which is both drawn-out and rises and falls, and is given especially by male in defence of mate, nest-site or brood, but is almost certainly given by both sexes, with a similar call, even more prolonged, given during pair formation; ducklings give piping “shripp shripp” in distress and softer twittering “tititi” in contentment (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Season variable, much dependent on water levels, but in SE Australia breeds mainly in Aug–Feb, following winter rains (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), with records of eggs and young in SW Australia in Nov–Jan (6 Chapman, A. and Lane, J.A.K. (1997). Waterfowl usage of wetlands in the south-east arid interior of Western Australia 1992–93. Emu. 97(1): 51–59. Close ). Monogamous and pair-bonds probably long-term (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). In single pairs or loose groups, especially at height of breeding season (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); nest is mound of down, in tree hollows  , crotches, nestboxes (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) or in old nests of other waterbirds, especially coots (Fulica) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), usually over water. Usually 6–8 white to creamy white eggs  (3–11), size 45–53 mm × 34–38 mm, calculated mass 31 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); incubation c. 26 days by female alone (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); chicks have light grey-brown down above , whitish below  , with prominent dark brown eye-patch and eyestripe  , and characteristic bill flaps already evident (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); fledging 45–60 days, tended by both adults (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Average of 6·4 ducklings hatched and 4·7 fledged per nest in one study involving 122 nests, in New South Wales (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Almost certainly breeds when c. 1 year old (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). No further information, e.g. on annual survival rates or longevity (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Not globally threatened (Least Concern). Widespread and locally abundant. Total population probably several hundred thousand, occasionally > 1,000,000 individuals, but difficult to calculate given nomadic character of this species which is opportunist breeder on inland floodwaters; surveys during 1980s and early 1990s in E Australia found on average 370,000 birds and sometimes > 750,000 birds (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). No long-term trends evident (7 Kingsford, R.T., Curtin, A.L. and Porter, J. (1999). Water flows on Cooper Creek in arid Australia determine ‘boom’ and ‘bust’ periods for waterbirds. Biological Conservation. 88(2): 231–248. Close ). In 1988, 45,536 birds counted in 472 wetlands in Victoria , and 6131 in 1398 wetlands in SW Australia . Hunters may kill large numbers, although only 30–40% of population occurs in areas open to hunting.