by Nicholas Munday, Adelaide Urban Birding.
The subject of this article is one of the most recognisable birds of your Adelaide Park Lands: the handsome and highly adaptable Pacific Black Duck (Anas superciliosa).
This duck is one of the most widespread and recognisable waterbirds across the Australasian region and the Pacific (as its common name suggests), with populations found throughout Australia, New Guinea, Indonesia, New Zealand, and various Pacific islands.
Its common name is a bit misleading, however, in respect of its colour, as these ducks are not particularly black but rather mottled brown, with the feathers across the back and wings edged in a pale cream that gives the bird a scaly appearance. It is not exactly clear where the “black” description comes from but it likely refers to the deep chocolate-brown crown and eye-stripe on the bird’s face.
Dark plumage around the face of the Pacific Black Duck likely gives the bird its common name (seen here near Adelaide Zoo in Park 11). Photograph: Nicholas Munday, Adelaide Urban Birding.
One of the most striking features of its appearance are the beautifully iridescent patches on its wing feathers, called a ‘speculum’ (or plural, ‘specula’). Depending on the lighting conditions, the speculum can appear purple, blue or green, with the brilliant colours being the result of refractive properties of the feathers rather than a pigment.
A preening Pacific Black Duck with its specula on full display, photographed here on the banks of the River Torrens near Adelaide Zoo in Park 11. Photo: Nicholas Munday, Adelaide Urban Birding.
Unlike the somewhat goose-like Australian Wood Duck (the subject of a previous article), the Pacific Black Duck is a true dabbling duck and has a classic (almost cartoonish) duck profile. It belongs to the genus Anas, which includes many familiar ducks worldwide such as the closely related Mallard (Anas platyrhynchos) of the northern hemisphere and its domesticated derivatives.
As the name suggests, dabbling ducks feed by “dabbling” in the water: tipping forward with tails upturned, or otherwise skimming the surface, as they search for aquatic plants, seeds, and invertebrates.
The Pacific Black Duck is also equally at home grazing on land, and may be seen foraging for fallen grain, insects, or even bread (regrettably) tossed by well-meaning park-goers, but this should not be seen as a good substitute for their natural diet (on the contrary, feeding seed and bread to ducks can be disastrous in the long term).
Adaptability is one of the defining features of this species. Pacific Black Ducks are as at home in natural wetlands as they are in urban ponds, drainage basins, and artificial lakes. They are essentially the stereotypical “duck pond” duck and do particularly well around people.
The broad, flat bill of the Pacific Black Duck is an archetypal dabbling duck feature which allows them to exploit a range of food sources. Photograph: Nicholas Munday, Adelaide Urban Birding.
Breeding occurs during spring and summer, with nests usually hidden in thick vegetation such as reeds and rushes. The ducklings are much more conspicuous, however, with delightfully fuzzy, yellow and brown stripes.
The ridiculously cute ducklings of the Pacific Black Duck. Photo: Nicholas Munday, Adelaide Urban Birding.
Although hyperabundant, the Pacific Black Duck is not without threats, and one of its most significant is also particularly difficult to combat in urban environments.
Pacific Black Ducks breed readily with the introduced Mallard and also domestic ducks, producing (usually) fertile offspring. Over time, this hybridisation can dilute the genetics of the native ducks. Many urban populations of Pacific Black Ducks now contain hybrids, often identifiable by their heavier build, sometimes curled tail feathers (in males), and less defined plumage; however, through multiple generations the impact of the foreign genetics becomes more subtle.
Despite the threat to its natural gene pool, the Pacific Black Duck holds its ground well in greater Adelaide and especially in your Adelaide Park Lands. Pacific Black Ducks will thrive virtually everywhere that water is provided (they’re even a common, if unwanted, visitor to backyard pools and fountains).
Within your Adelaide Park Lands, they can be found in especially large numbers in Botanic Park and Adelaide Botanic Garden (Park 11), Rymill Park / Murlawirrapurka (Park 14), Victoria Park / Pakapakanthi (Park 16), Veale Gardens (Park 21), and all the parks that border the River Torrens, such as Possum Park / Pirltawardli (Park 1) and Red Gum Park / Karrawirra (Park 12).
Pacific Black Duck at Rymill Park (Park 14). Photograph: Nicholas Munday, Adelaide Urban Birding.
And remember that, while it may be tempting to feed them, human food (particularly bread) is not healthy for ducks. Observing them foraging naturally is far more rewarding, for both the duck and observer.
There is an iNaturalist page where citizen scientists (like you) have recorded sightings of Pacific Black Ducks in your Adelaide Park Lands and elsewhere: https://www.inaturalist.org/taxa/6987-Anas-superciliosa
***
Top (banner) photo: Pacific Black Duck by the River Torrens by Nicholas Munday, Adelaide Urban Birding. Nicholas Munday, Adelaide Urban Birding
To find out about other birds in your Adelaide Park Lands, check out our What Bird is That? series.
Nicholas Munday is an Environment and Planning Lawyer with degrees in Law and Science (Evolutionary Biology and Ecology) from the University of Adelaide. He has a strong interest in biodiversity conservation and runs the ‘Adelaide Urban Birding’ Instagram (@adelaideurbanbirding) account dedicated to his photography of native birds in the Adelaide Metropolitan area.
In his free time, Nicholas is well-known in the Adelaide choral music and theatre communities, and also enjoys bushwalking, writing, and (of course) photography.
The opinions expressed in this article are entirely those of the author. This author is not affiliated with the Adelaide Park Lands Association.
