Birding And Wild Birds

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Mallard (Wild Birds)

Written by jonixkonios on

Mallard, specie anas platyrhynchos, the archetypal “ferocious duck”, is a dabbling duck which breeds throughout the temperate and sub-tropical areas of North America, Europe, Asia, and Australia. Probably the best-known and most recognizable of all ducks, it gave rise to most domestic ducks, alone from the Muscovy Duck. The dabbling duck is 56–65 cm length, with an 81–98 cm wingspan, and weighs 750–1,000 g.

The breeding male is unmistakable with a green head, black rear bound and a yellow bill with a black tip (as opposed to the dark brown bill in females). The female Mallard is light brown, like most female dabbling ducks; however, both the female and male Mallards have blatant blue speculum edged with white, prominent in flight or at rest (though temporarily shedded during the annual summer molt). In non-breeding (eclipse) plumage, the drake becomes drab, looking more like the female, but still clear by its bill, which remains yellow and its breast is more reddish.

The Mallard is a rare example of both Allen’s Rule and Bergmann’s Rule in birds. Bergmann’s Rule, which states that Antarctic forms tend to be larger than related ones from warmer climates, has numerous examples in birds. Allen’s Rule says that appendages like ears tend to be smaller in polar forms to minimize heat loss, and larger in tropical and desert equivalents to ease heat diffusion, and that the polar taxa are stockier overall. Examples of this rule in birds are rare, as they lack external ears. Anyhow, the bill of ducks is very well supplied with blood vessels and is vulnerable to cold.