Wednesday, Oct 22, 2014

Shelducks

Australian Shelduck


Male Ruddy Shelduck Tadorna ferruginea The Shelducks, genus Tadorna, are a group of large birds in the Tadorninae subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans.

The shelducks are a group of larger often semi-terrestrial waterfowl, which can be seen as intermediate between geese (Anserinae) and ducks.

They were originally known as "sheldrakes", this remained the most common name until the late 19th century. The word is still sometimes used to refer to a male shelduck and can also occasionally refer to the Canvasback (Aythya valisineria) of North America.


Description

They are mid-sized (some 50-60 cm) Old World waterfowl. The sexes are colored slightly different in most species, and all have a characteristic upperwing coloration in flight: the tertiary remiges form a green speculum, the secondaries (shorter, upper "arm" feathers) and primaries are black, and the coverts (forewing) are white.


Diet / Feeding

Their diet consists of small shore animals (winkles, crabs etc.) as well as grasses and other plants.

Common Shelduck Male (Left); Female (Right) Tadorna tadorna


Cape Shelduck or South African Shelduck, Tadorna canaSystematics

The genus name Tadorna comes from Celtic roots and means "pied waterfowl", essentially the same as the English "shelduck".

The namesake genus of the Tadorninae, Tadorna is very close to the Egyptian Goose and its extinct relatives from the Madagascar region, Alopochen. While the classical shelducks form a group that is obviously monophyletic, the interrelationships of these, the aberrant Common and especially Radjah Shelducks, and the Egyptian Goose were found to be poorly resolved by mtDNA cytochrome b sequence data; this genus may thus be paraphyletic.

Fossil bones from Dorkovo (Bulgaria) described as Balcanas pliocaenica may actually belong to this genus. They have even been proposed to be referable to the Common Shelduck, but their Early Pliocene age makes this rather unlikely.

Paradise ShelducksCape Shelduck or South African Shelduck, Tadorna cana


Copyright: Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia.org.


Relevant Resources




Diet / Feeding:

The diet of shelducks consists of small shore animals (winkles, crabs etc) , grasses and other plants.

Raja Shelduck or Radjah Shelduck (Tadorna radjah) Ducks generally feed on larvae and pupae usually found under rocks, aquatic animals, plant material, seeds, small fish, snails and crabs.

Feeding Ducks ...

We all enjoy ducks and many of us offer them food to encourage them to come over and stay around - and it works! Who doesn't like an easy meal!

However, the foods that we traditionally feed them at local ponds are utterly unsuitable for them and are likely to cause health problems down the road. Also, there may be local laws against feeding this species of bird - so it's best to check on that rather than facing consequences at a later stage.

Please note that feeding ducks and geese makes them dependent on humans for food, which can result in starvation and possibly death when those feedings stop. If you decide to feed them, please limit the quantity to make sure that they maintain their natural ability to forage for food themselves - providing, of course, that natural food sources are available.



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