The Hardhead, known scientifically as Aythya australis and colloquially as the white-eyed duck, is a distinctive species and the sole true diving duck native to Australia. This bird is characterized by its more rounded shape compared to other ducks and a size that typically does not exceed 45 cm in length, though it can occasionally reach up to 60 cm.
Upon observing the Hardhead, one will notice the uniform chocolate-brown plumage adorning the upper parts of both sexes, with rufous flanks and a white underbelly that may be hidden when the bird is afloat. The wings feature white trailing edges and are predominantly white on the underside. The male Hardhead boasts striking white eyes, while the female's eyes are a more subdued brown.
The Hardhead shows a preference for larger bodies of water such as lakes, swamps, and rivers with deep, still waters. However, they are also known to inhabit smaller streams, flooded grasslands, and shallow pools. They tend to avoid coastal waters and are rarely seen on land, never perching in trees.
Common in the south-east of Australia, particularly in the Murray-Darling Basin and near coastal regions, the Hardhead exhibits a moderate nomadic behavior. During droughts, they disperse widely, reaching locations as distant as New Guinea, New Zealand, and various Pacific Islands, where they may even breed for a season or two.
Hardheads are adept divers, often submerging for lengthy periods, up to a minute, to forage. They dive with a graceful ease, causing barely a ripple as they lower their heads and propel themselves with their webbed feet. Their diet is diverse, consisting of small aquatic organisms and water plants.
The Hardhead is typically a silent bird. However, the male can produce a soft, wheezy whistle and a 'whirr', while the female may emit a loud, rattling 'gaark'.
The Hardhead is classified as Least Concern on the IUCN Red List of Threatened Species, indicating a stable population across its extensive range.