Chestnut Teal Anas castanea Scientific name definitions

35–46 cm; male 562–816 g, female 505–766 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 ). Only likely to be confused with A. gibberifrons and A. rhynchotis, but latter has obviously different bill and former has much less colourful plumage than male of present species; <em>A. gibberifrons</em> is overall much paler, with greyish, rather than brown, tones to plumage, and always has much more obvious white chin/throat patch than present species, even juveniles. Breeding male has iridescent bottle green head , which may appear bronze or black in certain lights, slight crest on nape, dark brown back, black rump and tail, rich chestnut breast to vent, with prominent dark blotching on flanks , dark brown wings with prominent white wedge along leading edge of black speculum  , narrow white tips to trailing edge and bronze-green oval patch on inner speculum, brown underwing with black-brown leading edge, conspicuous white axillaries and central wing-coverts; blue-grey bill with darker culmen ridge, grey legs and feet, and crimson-red eyes. Adult female is streaked and scalloped dark brown, generally with richer tone to body plumage than A. gibberifrons but less obvious pale chin and more streaked head ; often has slight chestnut tone to underparts and some green iridescence in crown. Non-breeding (eclipse) male much like female, but has darker head, with smudgy white near white and darker undertail-coverts. Juvenile resembles female but is generally paler, with breast and belly streaked (rather than blotched) and has dull brown eyes.

• Pacific Black Duck x Chestnut Teal (hybrid) Anas superciliosa x castanea
• Gray x Chestnut Teal (hybrid) Anas gracilis x castanea

SW, N, E & SE Australia, and Tasmania.

Favours estuaries, coastal lagoons and marshes. Also along coast (e.g. in saltmarshes and mangrove swamps) (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, regularly but less commonly, in inland waters, including lower reaches of rivers, saltpans and saltwater lakes (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 ); locally also recorded in large numbers at sewage treatment lagoons (2 Murray, C.G. and Hamilton, A.J. (2010). Perspectives on wastewater treatment wetlands and waterbird conservation. Journal of Applied Ecology. 47: 976–985. Close ).

Mostly sedentary, with small-scale dispersion inland and following coast on both sides of Australia. However, vagrants have occurred throughout Australia and in S New Guinea (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 ), as well as on Lord Howe I (where bred in 1994) and in New Zealand (first records Jun–Jul 1991 and May–Jul 1992, but has been almost annual recently) (3 Moore, J. and Moore, M. (1992). A Chestnut Teal at the Manawatu River estuary – a new bird for New Zealand. Notornis. 39(4): 289–292. Close , 4 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 ).

Feeds by dabbling, upending (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 mud filtering in very shallow waters, and presumably takes similar kinds of food (perhaps with greater proportion of invertebrates) (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 ) to that taken by A. gracilis, with which it often forms mixed flocks. Study in S Victoria found that birds spent on average 21·2% of daytime feeding and 55·3% resting, with clear peaks in foraging activity around sunrise and sunset (especially the former), and upending (48·7%) and dipping (40·3%) were the commonest foraging methods (5 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 ). Usually observed in pairs year-round, but in non-breeding season also forms very large 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 ).

Generally noisy in flocks, calling almost constantly at low intensity, especially during display and in flight; most characteristic is loud, laugh-like “Decrescendo” call of female and clear, sharp, whistled “gedee-oo” of male in display (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 ). Repertoire considered identical to that of A. gracilis, although latter has display call slightly higher-pitched than that of present species, but there is no evidence that the two species can easily be separated using voice, especially as considerable individual variation exists in both (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 ).

Starts Jun/Nov, mainly about Aug, typically following sustained rainfall and associated flooding, especially if several months have elapsed without possibility to breed (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 ); often double- and perhaps triple-brooded, with replacement clutches also laid, if first brood lost (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 ). Monogamous and forms long-term, probably life-long, pair-bonds, with no evidence of sustained polygamous bonds or promiscuity; pairs usually first form in first autumn or winter (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 concentrations; nest (site selected by both pair-members) (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 ) is lined with down, situated on ground among vegetation or in natural cavity (usually tree hollows) (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 7–10 pale cream eggs  (5–17), laid at 24-hour intervals, size 35–57 mm × 35–41 mm, mean mass 44 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 23–29 days by female alone, guarded by male , commencing when clutch complete (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 brown down  on upperparts , paler below and on spot at sides of rump, and weight at one day old 21–34 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 ); fledging c. 56–80 days, with young typically cared for by both adults, sometimes by male alone, e.g. if female initiates second clutch prior to first brood fledging, and dispersal of young thereafter is gradual (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 ). Predators can include feral cats (Felis catus) (6 Kirkwood, R., Dann, P. and Belvedere, M. (2005). A comparison of the diets of feral cats Felis catus and red foxes Vulpes vulpes on Phillip Island, Victoria. Austr. Mammalogy. 27: 89–93. Close ). Sexual maturity at c. 1 year. Hatching success of 65–78·3% recorded.

Not globally threatened (Least Concern). Outnumbered c. 8:1 by A. gracilis, with an overall population most recently estimated at > 45,000 birds, perhaps even as many as 250,000 individuals, with no evidence of long-term trends, either positive or negative, over last two decades of 20th century (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 ). Widely scattered, but only locally common, especially in SE Australia, where considered the most abundant duck in Victoria and on Tasmania (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 ); scarce or rare elsewhere, being generally much less common inland of Great Divide in E Australia, with only scattered records in more arid parts of New South Wales and SE Queensland (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 ). Population in extreme SW Australia estimated at just 1000 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 ). Hunting, and destruction or modification of coastal wetlands caused decline in earlier parts of 20th century. Partial censuses in Victoria yielded 19,143–31,446, where it represents 6–10% of total ducks counted there, and 465–1140 birds in SW Australia, while during period 2000–2007 up to 10,147 birds were recorded at Coorong South Lagoon, in SE South Australia (7 Paton, D.C., Rogers, D.J., Hill, B.M., Bailey, C.P. and Ziembicki, M. (2009). Temporal changes to spatially stratified waterbird communities of the Coorong, South Australia: implications for the management of heterogenous wetlands. Animal Conservation. 12(5): 408–417. Close ). The nestbox instalment programme has been seen to be very useful in helping this species. Between 58–74% of the population is found in waters open to shooting, and the species is an important target of wildfowlers in Victoria and Tasmania (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 ).