Introduction

The Cotton Pygmy-goose (Nettapus coromandelianus) is a very small perching duck of freshwater wetlands across South and Southeast Asia, extending southwards into northern and eastern Australia. It is also known as the Cotton Teal in some regions. Despite its goose-like proportions, it belongs to the duck family Anatidae and is one of three living species of pygmy-goose.

Physical Description

The Cotton Pygmy-goose is a compact waterbird, generally about 30 centimetres long, with a short bill, rounded head and relatively short legs. It is adapted for swimming but can also perch and nest in tree hollows.

Adult males are strongly patterned. They have a largely white face, neck and underparts, a dark green crown and upperparts, and a contrasting dark band across the breast. The wings are dark with conspicuous white markings, especially in flight. Females are duller, with brownish-grey plumage, a paler face and a prominent dark line through the eye. Juveniles resemble females but are generally less sharply marked.

Plumage varies geographically. The Australian form, traditionally treated as the subspecies N. c. albipennis, is notably pale and has extensive white in the wing. Subspecies treatment and the limits of geographic variation may differ between taxonomic authorities.

Range and Habitat

The species occurs from the Indian subcontinent eastwards through mainland Southeast Asia and parts of Indonesia and the Philippines, with a southern range extending into northern and eastern Australia. In Australia, it is concentrated mainly in coastal and subcoastal Queensland, with occasional records farther south.

Cotton Pygmy-geese favour deep, permanent or semi-permanent freshwater wetlands with open water and abundant floating or submerged vegetation. Typical habitats include lagoons, marshes, floodplain waterholes, farm dams and large impoundments. Water lilies, pondweed, hydrilla and similar aquatic plants are particularly important for feeding and cover.

The species is not regarded as a long-distance migrant throughout its range. Many populations are resident or make local movements in response to water levels, seasonal rainfall and food availability. In Australia, local and seasonal movements may be noticeable when wetlands dry or water conditions change.

Behaviour and Diet

Cotton Pygmy-geese are usually encountered singly, in pairs or in small groups, although larger flocks may gather on productive wetlands, particularly outside the breeding season. They spend much of their time swimming among floating plants and may rest on logs, banks or emergent vegetation.

The diet consists mainly of aquatic plant material, including seeds, flowers, leaves and other soft parts of floating and submerged plants. They feed at the water’s surface and may dip the head and neck below the surface while picking vegetation. Small aquatic animals, including insects and other invertebrates, may also be taken, but plant material forms the main part of the diet.

Breeding usually occurs near suitable permanent water. Nests are placed in natural tree hollows, often in dead or living trees close to, or standing within, wetlands. The female incubates the eggs, while the male remains nearby and helps guard the territory. Reported clutch sizes vary between regions, with commonly cited Australian records ranging from about 6 to 11 eggs and some regional sources reporting larger clutches. Pairs may remain together outside the breeding season and can join small flocks.

Identification Tips

Look for a very small duck with a rounded head, short bill and a habit of swimming among floating vegetation. The adult male is recognised by his white face and neck, glossy dark-green crown and back, dark breast band and strong white wing markings.

Females and immature birds are less striking. Their most useful features are the small size, pale face, dark eye-line and compact shape. In flight, the white wing pattern is especially helpful.

In northern Australia, compare it carefully with the Green Pygmy-goose (Nettapus pulchellus). The Cotton Pygmy-goose generally shows a much whiter face and neck, whereas the Green Pygmy-goose has more extensive green on the head and upperparts. Wing pattern, head colour and the amount of white are useful when the birds are swimming or flying together.

Conservation Status

The Cotton Pygmy-goose is currently assessed as Least Concern on the IUCN Red List. This global category does not mean that all populations are secure. Local populations may be affected by wetland drainage, altered water regimes, declining water quality, agricultural expansion, urban development and the loss of mature or dead trees containing suitable nest hollows.

Invasive aquatic plants can change the structure and quality of feeding wetlands, while the removal of standing dead timber near water can reduce nesting and roosting opportunities. Conservation measures include protecting permanent freshwater wetlands, maintaining natural hydrology, retaining hollow-bearing trees near water and controlling invasive aquatic weeds. Local monitoring is important because population conditions can vary substantially between regions.

Frequently Asked Questions

Where does the Cotton Pygmy-goose live?

It occurs across South and Southeast Asia and extends southwards into northern and eastern Australia. It is most often found on freshwater lakes, lagoons, marshes, floodplain waterholes and farm dams with abundant aquatic vegetation.

Is the Cotton Pygmy-goose a goose or a duck?

It is a duck in the family Anatidae. The common name refers to its compact, goose-like appearance, but pygmy-geese are small perching ducks rather than true geese.

What does the Cotton Pygmy-goose eat?

It feeds mainly on aquatic vegetation, including seeds, flowers, leaves and other plant parts. Small aquatic invertebrates may also be eaten.

Where does the Cotton Pygmy-goose nest?

It nests in natural tree hollows, usually in or near freshwater wetlands. The availability of suitable hollow-bearing trees can therefore be important for local breeding populations.

How can the Cotton Pygmy-goose be identified?

The adult male is a tiny duck with a white face and neck, dark green crown and back, dark breast band and prominent white wing markings. Females and juveniles are browner, with a distinctive dark eye-line.

Is the Cotton Pygmy-goose endangered?

The species is globally classified as Least Concern, but habitat loss and changes to wetland water regimes can threaten local populations. Protecting freshwater wetlands and suitable nesting trees remains important.

References

• BirdLife International. n.d. Cotton Pygmy-goose Nettapus coromandelianus. BirdLife DataZone species factsheet. Available at: https://datazone.birdlife.org/species/factsheet/cotton-pygmy-goose-nettapus-coromandelianus (accessed 8 September 2026).
• International Ornithologists’ Union. 2025. IOC World Bird List, version 15.1. World Bird Names. Available at: https://www.worldbirdnames.org/new/ioc-lists/master-list-2/ (accessed 8 September 2026).
• Cornell Lab of Ornithology. n.d. Cotton Pygmy-Goose Nettapus coromandelianus. eBird species account. Available at: https://ebird.org/portugal/species/copgoo1/TH-83 (accessed 8 September 2026).
• Queensland Department of the Environment, Tourism, Science and Innovation. n.d. Identifying waterbirds. WetlandInfo. Available at: https://wetlandinfo.detsi.qld.gov.au/wetlands/ecology/components/biota/fauna/fauna-taxon/birds/other-bird/ (accessed 8 September 2026).
• Marchant, S. and Higgins, P. J., eds. 1990. Handbook of Australian, New Zealand and Antarctic Birds. Volume 1, Ratites to Ducks. Oxford University Press, Melbourne.
• Beruldsen, G. 2006. Breeding behaviour and status of Cotton Pygmy-goose Nettapus coromandelianus in south-east Queensland. The Sunbird 36(2): 1–21. Available at: https://birdsqueensland.org.au/sunbird_issues/articles/Vol_36/Beruldsen_2006_v36_2_1-21.pdf (accessed 8 September 2026).
• Lavery, H. J. 1966. Pygmy geese in Australia. Queensland Agricultural Journal 92: 294–299. Available at: https://era.dpi.qld.gov.au/id/eprint/6157/1/Vol_92NS_No_5_1966eRA.pdf (accessed 8 September 2026).
• Queensland Government. 2024. Native animals of Queensland: Cotton pygmy-goose Nettapus coromandelianus. WetlandInfo and WildNet species information. Available at: https://wetlandinfo.detsi.qld.gov.au/wetlands/facts-maps/wildlife/?AreaID=queensland&Kingdom=animals&SpeciesFilter=Native (accessed 8 September 2026).