The HARDHEAD (Aythya australia) is the only true diving duck found in Australia. Hardheads are common in the south-east of Australia, particularly in the Murray-Darling Basin, but also in wetter country near the coasts. They are moderately nomadic in normal years, but disperse widely in times of drought. Significant numbers reach as far afield as New Guinea, New Zealand, and the islands of the Pacific, where they can remain for some time, even breeding for a season or two.
Like the other members of the pochard group, hardheads feed by diving deeply, often staying submerged for as long as a minute at a time. They slip under water with barely a ripple, simply lowering their heads and thrusting with their powerful webbed feet. They eat a broad range of small aquatic creatures and supplement this with water weeds. They prefer larger lakes, swamps and rivers with deep, still water, but are often seen in smaller streams, flooded grasslands and shallow pools. As a general rule they avoid coastal waters and rarely come to land and never perch in trees.
They are small by duck standards, usually not much more than 45 cm long but sometimes reaching 60 cm and they are noticeably more rounded in overal form than most ducks. Both male and female are a fairly uniform chocolate-brown above, with rufous flanks and white undersides (which are often not visible if the duck is in the water). In the male the eyes are a striking white, in the they female, brown.
Widespread throughout its large range, the hardhead is evaluated as "Least Concern" on the IUCN Red List of Threatened Species (it's great to know that some species still have a chance of continuance in our world).
Unfortunately the story is not so happy for the HUIA (Heteralocha acutirostris) which was the largest species of New Zealand wattlebird, endemic to the North Island of New Zealand, Its extinction in the early 20th century had two primary causes. The first was rampant overhunting to procure Huia skins for mounted specimens, which were in worldwide demand by museums and wealthy private collectors. Huia were also hunted to obtain their long, striking tail feathers for locally fashionable hat decorations. The second major cause of extinction was the widespread deforestation of the lowlands of the North Island by European settlers to create pasture for agriculture. Most of these forest were ancient, ecologically complex primary forests, and Huia were unable to survice in regenerating secondary forests. The last confirmed sighting of a Huia was on 28th December, 1907 in the Tararua Ranges. Further credible sightings in Wellington were reported until 1922 and in Te Urewera National Park in the early 1960s. One can only hope these magnificent birds have managed to survive somewhere in a place still be be discovered.
The Huia belonged to a family found only in New Zealand, a family so ancient that no relation is found elsewhere. It was remarkable for having the most pronounced sexual dimorphism in bill shape of any bird species in the world. The female's beak was long, thin and arched downward while the male's was short and stout, like that of a crow. This is well demonstrated in the above painting by J.G..Keulemans.
It is pheasant-sized with a total length o 65 cm (26 in) with a long neck and small head. It is a noisy species, with a variety of hoarse calls, including groans, croaks, hisses and grunts. These calls are often associated with body movements, such as wing spreading. Calls are used to maintain contact between individuals in groups, warning of threats and intruders, and by chicks begging for food.
Wikipedia has lots more information about this unusual bird; far too much for me to write here but it is well worth checking it out as apparently it is another creature about which there is much debate in regard to its phylogenetic relationships as no evolutionary hypothesis has been proposed and that situation has worsened with the available of DNA sequence data.
Hope you enjoyed reading about these three very different species of bird.