Mallard

From Encyclopedia Jr, free information reference for Kids

For other uses, see Mallard (disambiguation).

1 Breeding behaviour
2 As a game bird
3 References
4 Photo gallery
5 External links

Mallard
Conservation status: Least concern^[1]

Male Mallard Duck in midflight

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Genus:	Anas
Species:	A. platyrhynchos

Binomial name

Anas platyrhynchos
Linnaeus, 1758

Subspecies

See Mexican Duck, Anas, and article text

The Mallard (Anas platyrhynchos; Greek for "flat-billed duck"^[2]), 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, and has been introduced into Australia and New Zealand. It is now the most common duck in New Zealand. 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; there are reports[1] of it eating frogs. 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.^[3]

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 is 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. It is sometimes separated as subspecies Greenland Mallard (A. p. conboschas).

The Mallard is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

Mallards are the parent stock of most domestic ducks, apart from the Muscovy Duck. In captivity, Mallards come in wild-type plumages as well as white and other colours. Although most of these colour variants are rare, there is a steady increase in the number of domestic collections containing these forms.

[edit] Breeding behaviour

Nesting Mallard duck

Female Mallard landing

Mallards form pairs only until the female lays eggs, at which time she is left by the male. The clutch is 8–13 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.^[4]

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).^[5]^[6])

[edit] As a game bird

Mallards are hunted and eaten as game. The flesh has a stonger flavour than that of the more commonly eaten domestic ducks. ^[7]

[edit] References

^ BirdLife International (2004). Anas platyrhynchos. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
^ Mallard on sou.edu/~rible/wildlife. Retrieved on 2006-03-01. Archived 2005-02-14
^ Mallard on animaldiversity.ummz.umich.edu. Retrieved on 2006-03-01.
^ Bagemihl, Bruce (1999). Biological Exuberance, Animal Homosexuality and Natural Diversity.
^ 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.
^ "Waitrose.com Food Glossary," Accessed November 8 2006

[edit] Photo gallery

Drake	Drake	Mallards in an urban environment.	Adult drake in full plumage
Adult drake in full plumage	Drake	Female	Drake
Female with ducklings	Ducklings	Drake	Female
Female with young ducklings	Mother with older ducklings	Female walking on grass	Female mallard