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The Mallard (Anas platyrhynchos; Greek for "flat billed duck"), also known in North America as the Wild Duck, is a common and widespread dabbling duck which breeds throughout the temperate and sub-tropical areas of North America, Europe and Asia. It also frequents Central America and the Caribbean. It is probably the best-known of all ducks.
This dabbling duck is 56-65 cm length, with an 81–98 cm wingspan, and weighs 750–1000 g. It is strongly migratory in the northern parts of its breeding range, and winters farther south. It is highly gregarious outside of the breeding season and will form large flocks. They are exceptionally fast flyers for their size, reaching speeds of 65 km/h (40 mph).
The breeding male is unmistakable, with a green head, black rear end and a blue speculum edged with white, obvious in flight or at rest. Males also possess a yellow bill with a black tip, whereas females have a dark brown bill.
The female Mallard is light brown, with plumage much like most female dabbling ducks. It can be distinguished from other ducks, by the distinctive speculum. In non-breeding (eclipse) plumage, the drake looks more like the female.
It is a bird of most wetlands, including parks, small ponds and rivers, and usually feeds by dabbling for plant food or grazing. It nests usually on a river bank, but not always particularly near water.
This is a noisy species. The male has a nasal call, whereas the female has the very familiar "quack" always associated with ducks.
Mallards frequently interbreed with the American Black Duck, Northern Pintail and domesticated species, leading to various hybrids. A Mallard has been recorded as living for 29 years.
The Mallard is one of the rare examples of both Allen's Rule and Bergmann's Rule in birds. Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds. Allen's Rule is that appendages like ears tend to be smaller in polar forms, to minimize heat loss, and larger in tropical and desert equivalents to facilitate heat diffusion, and that the polar taxa are stockier overall. Examples of this rule in birds are rare, as they lack ears. However, the bill of ducks is very well supplied with blood vessels and vulnerable to cold.
The size of the Mallard varies clinally, and birds from Greenland, although larger than birds further south, have smaller bills and are stockier.
The Mallard is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
Breeding behaviour
Mallards form pairs only until the female lays eggs, at which time she is left by the male. The clutch is 9–13 eggs, which are incubated for 27–28 days to hatching with 50–60 days to fledging. The ducklings are precocial, and can swim and feed themselves on insects as soon as they hatch, although they stay near the female for protection. Young ducklings are not naturally waterproof and rely on the mother to provide waterproofing. Mallards also have rates of male-male sexual activity that are unusually high for birds. In some cases, as many as 19% of pairs in a Mallard population are male-male homosexual.Bagemihl, Bruce (1999). Biological Exuberance, Animal Homosexuality and Natural Diversity.
When they pair off with mating partners, often one or several drakes will end up "left out". This group will sometimes target an isolated female duck — chasing, pestering and pecking at her until she weakens (a phenomenon referred to by researchers as rape flight), at which point each male will take turns copulating with the female. Male Mallards will also occasionally chase other males in the same way. (In one documented case, a male Mallard copulated with another male he was chasing after it had been killed when it flew into a glass window (see animal sexuality).Moeliker, C.W. (2001). "The first case of homosexual necrophilia in the Mallard Anas platyrhynchos," 243-247.MacLeod, Donald (2005). "Necrophilia among ducks ruffles research feathers," Education Guardian, 8 March.)
References
Photo gallery
External links
- RSPB A to Z of UK Birds
- Birdguides Mallard Page
- Mallard videos on the Internet Bird Collection
Anas | Ducks | Migratory birds (Eastern hemisphere) | Migratory birds (Western hemisphere)
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"Mallard"