Bronze-winged duck (Spectacled duck)

Speculanas specularis

Bronsvleugeleend (Goudspiegeleend) / Kupferspiegelente / Canard à ailes bronzées

The bronze-winged duck also known as the spectacled duck, is a dabbling duck and the sole member of its genus Speculanas. It is often placed in Anas with most other dabbling ducks, but its closest relative is either the crested duck or the Brazilian duck, which likewise form monotypic genera. Together they belong to a South American lineage which diverged early from the other dabbling ducks and may include the steamer ducks.

Named after the "bronze" speculum this species is also known as "pato perro" or "dog-duck" after the harsh barking call of the female.

The bronze-winged duck lives among forested rivers and fast-flowing streams on the lower slopes of the South American Andes, in central and southern Chile and adjacent parts of Argentina. The sexes are alike.

As noted by Johnsgard (2010): "Most observers agree that heavily forested rivers that are relatively swift-flowing are the preferred habitat of this species, although they also occur on slow-moving rivers and on pools or ponds of the adjoining forest areas. They are said to consume both vegetable and animal materials, and have been observed eating small snails that abound on stony shingle beaches. Stomach remains from two birds that were examined contained the seeds of water crowfoot (Batrachium), water milfoil (Myriophyllum), and a bulrush, leaves of water crowfoot, foliage and seeds of a pondweed, and caddis fly larvae as well as a few other aquatic insect remains (Phillips, 1922–26). In captivity at least the birds seem to spend a good deal of time on land and have not been observed diving for food."

This species is classified as Near Threatened as it has a small global population within which all its subpopulations are small. If it was demonstrated to be declining it would qualify as Vulnerable (IUCN, 2012).

The population is estimated to number fewer than 10,000 individuals, and so is placed in the band 2,500-9,999 individuals (R. Schlatter in litt. 2002). This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Potential threats include predation by Mustela vison (M. Pearman in litt. 1999), increased pressure from tourism (e.g. in Los Glaciares National Park [S. Imberti in litt. 1999]), and salmon farming and trout stocking on Chilean rivers (A. Jaramillo in litt. 1999).

It breeds mostly by fast-flowing rivers in forested regions up to 1,800 m, but also on wetlands, ponds and lakes away from dense forests (Carboneras 1992a, Parker et al.1996, S. Imberti in litt. 1999, Delany and Scott 2002). Breeding begins in September-October, with egg-laying in October-November, and a c.30 day incubation period in captivity (Carboneras 1992a). It feeds on seeds, leaves and stems of aquatic plants, variable amounts of aquatic invertebrates, and sometimes in the leaf-litter of forests away from water (Carboneras 1992a, S. Imberti in litt. 1999).

It is well represented within protected areas, occurring in seven Argentinean National Parks (Delany and Scott 2002) and Torres del Paine National Park, Chile (A. Jaramillo in litt. 1999). Census and monitor the population. Research potential threats from tourism, predation and fish farming. Ensure the effective protection of the protected areas in which it occurs.

More information: http://www.iucnredlist.org/details/22680136/0

Above: adult Bronze-winged duck

Above: adult Bronze-winged ducks (female left)

Above: adult Bronze-winged duck (female)

Above: adult Bronze-winged ducks

Above: adult Bronze-winged ducks (drake in front)

Above: adult Bronze-winged ducks (drake in front)

Above: adult Bronze-winged ducks (drake in front)