Australian blue-billed duck

Oxyura australis

Australische stekelstaart / Aus. Ruderente / Erismature d'Australie

The blue-billed duck is a small Australian stiff-tailed duck, with both the male and female growing to a length of 40 cm (16 in). The male has a slate-blue bill which changes to bright-blue during the breeding season, hence the duck’s common name. The male has deep chestnut plumage during breeding season, reverting to a dark grey. The female retains black plumage with brown tips all year round. The duck is endemic to Australia's temperate regions, inhabiting natural inland wetlands and also artificial wetlands such as sewage ponds in large numbers. It can be difficult to observe due to its cryptic nature during its breeding season through autumn and winter. The male duck exhibits a complex mating ritual. The blue-billed duck is omnivorous, with a preference for small aquatic invertebrates. 

This species has a moderately small population and is therefore classed as Near Threatened (IUCN, 2012). It faces a number of threats and the population may be smaller than currently estimated. If it is found that the population size is very small and declining, the species may qualify as threatened.

It occupies permanent deep water-bodies in southern Australia with the population estimated at c.12,000 mature individuals, or c.15,000 birds overall (R. Jaensch in litt. 2005 to Wetlands International 2006). The species is found particularly in the Murray-Darling basin and southern Victoria.

The species is found on terrestrial wetlands in temperate regions, that are freshwater to saline, and may be natural or artificial. It nests in rushes, sedges, Lignum Muehlenbeckia cunninghamii and paperbark Melaleuca, and it lays 5-6 eggs. It feeds on aquatic insect larvae, seeds and plant matter. During autumn and winter the species aggregates in large flocks but disperses to smaller waterbodies when breeding. Aggregations also occur during drought.

The species is not kept in aviculture outside of Australia. The last specimen alive in Europe was kept in the Netherlands untill the 1990's. 

More information: http://www.iucnredlist.org/details/22679827/0

Above: adult male blue-billed duck. Photo by Trevor Anderson/ Australian Avifauna

Above: a pair of blue-billed ducks and Magpie geese. Photo by Trevor Anderson/ Australian Avifauna

Above: adult male blue-billed duck. Photo by Trevor Anderson/ Australian Avifauna

Above: adult female with her brood. Photo by Trevor Anderson/ Australian Avifauna

Above: Close-ups of Stiff-tailed ducks (genus Oxyura) for identification. Click to enlarge.