Template:Short description {{#invoke:other uses|otheruses}} Template:EngvarB Template:Good article Template:Use dmy dates Template:Speciesbox Template:Birdsong
The mallard (Template:IPAc-en) or wild duck (Anas platyrhynchos) is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. Belonging to the subfamily Anatinae of the waterfowl family Anatidae, mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes.
Males (drakes) have green heads, while the females (hens) have mainly brown-speckled plumage. Both sexes have an area of white-bordered black or iridescent purple or blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. The mallard is Template:Convert long, of which the body makes up around two-thirds the length. The wingspan is Template:Convert and the bill is Template:Convert long. It is often slightly heavier than most other dabbling ducks, weighing Template:Convert.
The female lays 8 to 13 creamy white to greenish-buff spotless eggs, on alternate days. Incubation takes 27 to 28 days and fledging takes 50 to 60 days. The ducklings are precocial and fully capable of swimming as soon as they hatch.
The non-migratory mallard interbreeds with indigenous wild ducks of closely related species through genetic pollution by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl. This species is the main ancestor of most breeds of domestic duck, and its naturally evolved wild gene pool has been genetically polluted by the domestic and feral mallard populations.
The mallard is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN), and, unlike many waterfowl, are considered an invasive species in some regions. It is a very adaptable species, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development.
Taxonomy and evolutionary historyEdit
The mallard was one of the many bird species originally described in the 1758 10thTemplate:Nbspedition of Systema Naturae by Carl Linnaeus.<ref name="Linnaeus1758" /> He gave it two binomial names: Anas platyrhynchos and Anas boschas.<ref>Template:Cite book</ref> The latter was generally preferred until 1906 when Einar Lönnberg established that A.Template:Nbspplatyrhynchos had priority, as it appeared on an earlier page in the text.<ref>Template:Cite journal</ref> The scientific name comes from Latin Anas, "duck" and Ancient Greek πλατυρυγχος, platyrhynchus, "broad-billed" (from πλατύς, platys, "broad" and ρυγχός, rhunkhos, "bill").<ref name="job90">Template:Cite book</ref> The genome of Anas platyrhynchos was sequenced in 2013.<ref name="Huang2013" />
The name mallard originally referred to any wild drake, and it is sometimes still used this way.<ref>Template:Citation</ref> It was derived from the Old French {{#invoke:Lang|lang}} or {{#invoke:Lang|lang}} for "wild drake" although its true derivation is unclear.<ref>Template:Cite book</ref> It may be related to, or at least influenced by, an Old High German masculine proper name {{#invoke:Lang|lang}}, clues lying in the alternative English forms "maudelard" and "mawdelard".<ref name="OED2" /> Masle (male) has also been proposed as an influence.<ref>Template:Cite book</ref>
Mallards frequently interbreed with their closest relatives in the genus Anas, such as the American black duck, and also with species more distantly related, such as the northern pintail, leading to various hybrids that may be fully fertile.<ref name="Phillips" /> The mallard has hybridised with more than 40 species in the wild, and an additional 20 species in captivity,<ref>Template:Cite book</ref> though fertile hybrids typically have two Anas parents.<ref>Template:Cite journal</ref> Mallards and their domestic conspecifics are fully interfertile; many wild mallard populations in North America contain significant amounts of domestic mallard DNA.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
Genetic analysis has shown that certain mallards appear to be closer to their Indo-Pacific relatives, while others are related to their American relatives.<ref name=johnson/> Mitochondrial DNA data for the D-loop sequence suggest that mallards may have evolved in the general area of Siberia. Mallard bones rather abruptly appear in food remains of ancient humans and other deposits of fossil bones in Europe, without a good candidate for a local predecessor species.<ref name="Kulikova et al. 2005" /> The large Ice Age palaeosubspecies that made up at least the European and West Asian populations during the Pleistocene has been named Anas platyrhynchos palaeoboschas.<ref>Template:Cite book</ref>{{#invoke:Listen|main}}Mallards are differentiated in their mitochondrial DNA between North American and Eurasian populations,<ref name="Kraus2011" /> but the nuclear genome displays a notable lack of genetic structure.<ref name="Kraus2013" /> Haplotypes typical of American mallard relatives and eastern spot-billed ducks can be found in mallards around the Bering Sea.<ref name="Kulikova et al. 2004" /> The Aleutian Islands hold a population of mallards that appear to be evolving towards becoming a subspecies, as gene flow with other populations is very limited.<ref name="Kulikova et al. 2005" />
Also, the paucity of morphological differences between the Old World mallards and the New World mallard demonstrates the extent to which the genome is shared among them such that birds like the Chinese spot-billed duck are highly similar to the Old World mallard, and birds such as the Hawaiian duck are highly similar to the New World mallard.<ref name=":3">Template:Cite journal</ref>
The size of the mallard varies clinally; for example, birds from Greenland, though larger, have smaller bills, paler plumage, and stockier bodies than birds further south and are sometimes classified as a separate subspecies, the Greenland mallard (A.Template:Nbspp.Template:Nbspconboschas).<ref name=":11">Template:Cite bookTemplate:Dead link</ref>
DescriptionEdit
The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. It is Template:Convert longTemplate:Sndof which the body makes up around two-thirdsTemplate:Sndhas a wingspan of Template:Convert,Template:R and weighs Template:Convert.<ref name="CRC" /> Among standard measurements, the wing chord is Template:Convert, the bill is Template:Convert, and the tarsus is Template:Convert.<ref name="Madge" />
The breeding male mallard is unmistakable, with a glossy bottle-green head and a white collar that demarcates the head and neck from the purple-tinged brown breast, grey-brown wings, and a pale grey belly.<ref>Template:Cite bookTemplate:Dead link</ref> The rear of the male is black, with white-bordered dark tail feathers.Template:R The bill of the male is a yellowish-orange tipped with black, with that of the female generally darker and ranging from black to mottled orange and brown.<ref>Template:Cite book</ref> The female mallard is predominantly mottled, with each individual feather showing sharp contrast from buff to very dark brown, a coloration shared by most female dabbling ducks, and has buff cheeks, eyebrow, throat, and neck, with a darker crown and eye-stripe.Template:R Mallards, like other sexually-dimorphic birds, can sometimes go though spontaneous sex reversal,<ref>Template:Cite journal</ref> often caused by damaged or nonfunctioning sex organs, such as the ovaries in mallard hens.<ref>Template:Cite journal</ref> This phenomenon can cause female mallards to exhibit male plumage, and vice versa (phenotypic feminisation or masculinisation). Both male and female mallards have distinct iridescent purple-blue speculum feathers edged with white, which are prominent in flight or at rest but temporarily shed during the annual summer moult.<ref name=":7">Template:Cite book</ref> Upon hatching, the plumage of the duckling is yellow on the underside and face (with streaks by the eyes) and black on the back (with some yellow spots) all the way to the top and back of the head.<ref name=":16">Template:Cite book</ref> Its legs and bill are also black.<ref name=":16" /> As it nears a month in age, the duckling's plumage starts becoming drab, looking more like the female, though more streaked, and its legs lose their dark grey colouring.
Template:R Two months after hatching, the fledgling period has ended, and the duckling is now a juvenile.<ref>Template:Cite book</ref> The duckling is able to fly 50–60 days after hatching. Its bill soon loses its dark grey colouring, and its sex can finally be distinguished visually by three factors: 1)Template:Nbspthe bill is yellow in males, but black and orange in females;<ref name=":12">Template:Cite bookTemplate:Self-published source</ref> 2)Template:Nbspthe breast feathers are reddish-brown in males, but brown in females;<ref name=":12" /> and 3)Template:Nbspin males, the centre tail feather (drake feather) is curled, but in females, the centre tail feather is straight.<ref name=":12" /> During the final period of maturity leading up to adulthood (6–10 months of age), the plumage of female juveniles remains the same while the plumage of male juveniles gradually changes to its characteristic colours.<ref name=":13">Template:Cite book</ref> This change in plumage also applies to adult mallard males when they transition in and out of their non-breeding eclipse plumage at the beginning and the end of the summer moulting period.<ref name=":13" /> The adulthood age for mallards is fourteen months, and the average life expectancy is three years, but they can live to twenty.<ref name="BTO" />
Several species of duck have brown-plumaged females that can be confused with the female mallard.<ref>Template:Cite bookTemplate:Dead link</ref> The female gadwall (Mareca strepera) has an orange-lined bill, white belly, black and white speculum that is seen as a white square on the wings in flight, and is a smaller bird.Template:R More similar to the female mallard in North America are the American black duck (A.Template:Nbsprubripes), which is notably darker-hued in both sexes than the mallard,<ref name=":17">Template:Cite book</ref> and the mottled duck (A.Template:Nbspfulvigula), which is somewhat darker than the female mallard, and with slightly different bare-part colouration and no white edge on the speculum.<ref name=":17" />
In captivity, domestic ducks come in wild-type plumages, white, and other colours.<ref name=":18">Template:Cite book</ref> Most of these colour variants are also known in domestic mallards not bred as livestock, but kept as pets, aviary birds, etc., where they are rare but increasing in availability.<ref name=":18" />
A noisy species, the female has the deep quack stereotypically associated with ducks.Template:R The female will often call with a sequence of 2–10 quacks in a row, starting loud and with the volume gradually decreasing.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Male mallards make a sound phonetically similar to that of the female, a typical quack, but it is deeper and quieter compared to that of the female. Research conducted by Middlesex University on two English mallard populations found that the vocalisations of the mallard varies depending on their environment and have something akin to a regional accent, with urban mallards in London being much louder and more vociferous compared to rural mallards in Cornwall, serving as an adaptation to persistent levels of anthropogenic noise.<ref>Template:Cite news</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
When incubating a nest, or when offspring are present, females vocalise differently, making a call that sounds like a truncated version of the usual quack. This maternal vocalisation is highly attractive to their young. The repetition and frequency modulation of these quacks form the auditory basis for species identification in offspring, a process known as acoustic conspecific identification.<ref>Template:Cite journal</ref> In addition, females hiss if the nest or offspring are threatened or interfered with. When taking off, the wings of a mallard produce a characteristic faint whistling noise.<ref>Template:Cite book</ref>
The mallard is a rare example of both Allen's Rule and Bergmann's Rule in birds.<ref>Template:Cite journal</ref> Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds,<ref>Template:Cite journal</ref> as in case of the Greenland mallard which is larger than the mallards further south.<ref name=":11" /> Allen's Rule says that appendages like ears tend to be smaller in polar forms to minimise heat loss, and larger in tropical and desert equivalents to facilitate heat diffusion, and that the polar taxa are stockier overall.<ref>Template:Cite journal</ref> Examples of this rule in birds are rare as they lack external ears, but the bill of ducks is supplied with a few blood vessels to prevent heat loss,<ref>Template:Cite book</ref> and, as in the Greenland mallard, the bill is smaller than that of birds farther south, illustrating the rule.<ref name=":11" />
Due to the variability of the mallard's genetic code, which gives it its vast interbreeding capability, mutations in the genes that decide plumage colour are very common and have resulted in a wide variety of hybrids, such as Brewer's duck (mallard × gadwall, Mareca strepera).<ref name="Audubon" />
Distribution and habitatEdit
The mallard is widely distributed across the Northern and Southern Hemispheres; in North America its range extends from southern and central Alaska to Mexico, the Hawaiian Islands,<ref name=":1">Template:Cite book</ref> across the Palearctic,<ref>Template:Cite book</ref> from Iceland<ref name=":2">Template:Cite book</ref> and southern Greenland<ref name=":1" /> and parts of Morocco (North Africa)<ref name=":2" /> in the west, Scandinavia<ref name=":2" /> and Britain<ref name=":2" /> to the north, and to Siberia,<ref>Template:Cite book</ref> Japan,<ref name="Yamaguchi 875–881">Template:Cite journal</ref> and South Korea.<ref name="Yamaguchi 875–881" /> Also in the east, it ranges to south-eastern and south-western Australia<ref>Template:Cite book</ref> and New Zealand<ref>Template:Cite book</ref> in the Southern hemisphere.Template:R<ref name="IUCN" /> It is strongly migratory in the northern parts of its breeding range, and winters farther south.<ref>Template:Cite book</ref><ref>Template:Cite book</ref> For example, in North America, it winters south to the southern United States and northern Mexico,<ref>Template:Cite book</ref><ref>Template:Cite book</ref> but also regularly strays into Central America and the Caribbean between September and May.<ref>Template:Cite book</ref> A drake later named "Trevor" attracted media attention in 2018 when it turned up on the island of Niue, an atypical location for mallards.<ref>Template:Cite news</ref><ref>Template:Cite news</ref>
The mallard inhabits a wide range of habitats and climates, from the Arctic tundra to subtropical regions.<ref>Template:Cite book</ref> It is found in both fresh- and salt-water wetlands, including parks, small ponds, rivers, lakes and estuaries, as well as shallow inlets and open sea within sight of the coastline.<ref>Template:Cite book</ref> Water depths of less than Template:Convert are preferred, with birds avoiding areas more than a few metres deep.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They are attracted to bodies of water with aquatic vegetation.Template:R
BehaviourEdit
FeedingEdit
The mallard is omnivorous and very flexible in its choice of food.<ref>Template:Cite journal</ref> Its diet may vary based on several factors, including the stage of the breeding cycle, short-term variations in available food, nutrient availability, and interspecific and intraspecific competition.<ref name="Krapu" /> The majority of the mallard's diet seems to be made up of gastropods,<ref name=":14">Template:Cite book</ref> insects (including beetles, flies, lepidopterans, dragonflies, and caddisflies),<ref>Template:Cite journal</ref> crustaceans,<ref name=":15">Template:Cite book</ref> other arthropods,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> worms,<ref name=":14" /> feces of other birds,<ref name=BOW>Template:Cite journal</ref> many varieties of seeds and plant matter,<ref name=":14" /> and roots and tubers.<ref name=":15" /> During the breeding season, male birds were recorded to have eaten 37.6% animal matter and 62.4% plant matter, most notably the grass Echinochloa crus-galli, and nonlaying females ate 37.0% animal matter and 63.0% plant matter, while laying females ate 71.9% animal matter and only 28.1% plant matter.<ref name="Swanson" /> Plants generally make up the larger part of a bird's diet, especially during autumn migration and in the winter.<ref name="Gruenhagen" /><ref name="Combs" />
The mallard usually feeds by dabbling for plant food or grazing; there are reports of it eating frogs, other amphibians, and fish, including carcasses.<ref name=":6">Template:Cite book</ref><ref name=BOW/> However, in 2017 a flock of mallards in Romania were observed hunting fledglings of small migratory birds when they land in the water, which included a grey wagtail and a black redstart. This was the first documented occasion they had been seen attacking and consuming large vertebrates.<ref>{{#invoke:citation/CS1|citation |CitationClass=web
}}</ref> It usually nests on a river bank, but not always near water. It is highly gregarious outside of the breeding season and forms large flocks, which are known as "sordes".<ref>Template:Cite book</ref>
- Mallard duck eating bread.jpg
Eating bread
- Fish-Eating Mallard.jpg
Eating a small fish
- Duck eating a Fish (5979923772).jpg
Eating a larger fish
- Mallard drake eating leopard frog Sand Lake WMD (14822335555).jpg
Eating a frog
BreedingEdit
Mallards usually form pairs (in October and November in the Northern Hemisphere) until the female lays eggs at the start of the nesting season, which is around the beginning of spring.<ref>Template:Cite book</ref> At this time she is left by the male who joins up with other males to await the moulting period, which begins in June (in the Northern Hemisphere).<ref>Template:Cite book</ref><ref>Template:Cite book</ref> During the brief time before this, however, the males are still sexually potent and some of them either remain on standby to sire replacement clutches (for female mallards that have lost or abandoned their previous clutch)<ref name=":20">Template:Cite book</ref> or forcibly mate with females that appear to be isolated or unattached regardless of their species and whether or not they have a brood of ducklings.<ref name=":20" /><ref>Template:Cite book</ref>
- Growth series (from youngest to oldest)
- Anas platyrhynchos MWNH 1048.JPG
Egg
- Mallard and ducklings - geograph.org.uk - 4473798.jpg
Young ducklings
- Mallard ducklings (3752889877).jpg
Older ducklings
- Duckling in Central Park (81320).jpg
Moulting
- Anas platyrhynchos juvenile JdP 2013-06-14 n01 retusche.jpg
Fledgling female and male
- Female Mallard IMG 1434.jpg
Adult female
Nesting sites are typically on the ground, hidden in vegetation where the female's speckled plumage serves as effective camouflage,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> but female mallards have also been known to nest in hollows in trees, boathouses, roof gardens and on balconies, sometimes resulting in hatched offspring having difficulty following their parent to water.<ref>{{#invoke:citation/CS1|citation |CitationClass=web
}}</ref>
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Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles.<ref name=":24">Template:Cite book</ref><ref name="Hauber2014">Template:Cite book</ref> They measure about Template:Convert in length and Template:Convert in width.<ref name="Hauber2014" /> The eggs are laid on alternate days, and incubation begins when the clutch is almost complete.<ref name="Hauber2014" /> Incubation takes 27–28Template:Nbspdays and fledging takes 50–60Template:Nbspdays.<ref name=":24" /><ref>Template:Cite book</ref> The ducklings are precocial and fully capable of swimming as soon as they hatch.<ref>Template:Cite news</ref> However, filial imprinting compels them to instinctively stay near the mother, not only for warmth and protection but also to learn about and remember their habitat as well as how and where to forage for food.<ref>Template:Cite book</ref> Though adoptions are known to occur, female mallards typically do not tolerate stray ducklings near their broods, and will violently attack and drive away any unfamiliar young, sometimes going as far as to kill them.<ref>{{#invoke:citation/CS1|citation
|CitationClass=web }}</ref>
When ducklings mature into flight-capable juveniles, they learn about and remember their traditional migratory routes (unless they are born and raised in captivity). In New Zealand, where mallards are naturalised, the nesting season has been found to be longer; eggs and clutches are larger and nest survival is generally greater compared with mallards in their native range.<ref>Template:Cite journal</ref>
In cases where a nest or brood fails, some mallards may mate for a second time in an attempt to raise a second clutch, typically around early-to-mid summer. In addition, mallards may occasionally breed during the autumn in cases of unseasonably warm weather; one such instance of a 'late' clutch occurred in November 2011, in which a female successfully hatched and raised a clutch of eleven ducklings at the London Wetland Centre.<ref>Template:Cite news</ref> During the breeding season, both male and female mallards can become aggressive, driving off competitors to themselves or their mate by charging at them.<ref>Template:Cite book</ref> Males tend to fight more than females and attack each other by repeatedly pecking at their rival's chest, ripping out feathers and even skin on rare occasions. Female mallards are also known to carry out 'inciting displays', which encourage other ducks in the flock to begin fighting.<ref>Template:Cite journal</ref> It is possible that this behaviour allows the female to evaluate the strength of potential partners.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The drakes that end up being left out after the others have paired off with mating partners sometimes target an isolated female duck, even one of a different species, and proceed to chase and peck at her until she weakens, at which point the males take turns copulating with the female.<ref name=":10">Template:Cite journal</ref> Lebret (1961) calls this behaviour "Attempted Rape Flight", and Stanley Cramp and K.E.L. Simmons (1977) speak of "rape-intent flights".<ref name=":10" /> Male mallards also occasionally chase other male ducks of a different species, and even each other, in the same way.<ref name=":10" /> In one documented case of "homosexual necrophilia", a male mallard copulated with another male he was chasing after the chased male died upon flying into a glass window.<ref name=":10" /> This paper was awarded an Ig Nobel Prize in 2003.<ref>Template:Cite book</ref>
Mallards are opportunistically targeted by brood parasites, occasionally having eggs laid in their nests by redheads, ruddy ducks, lesser scaup, gadwalls, northern shovellers, northern pintails, cinnamon teal, common goldeneyes, and other mallards.<ref>Template:Cite book</ref> These eggs are generally accepted when they resemble the eggs of the host mallard, but the hen may attempt to eject them or even abandon the nest if parasitism occurs during egg laying.<ref name=BNA/>
Predators and threatsEdit
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In addition to human hunting, mallards of all ages (but especially young ones) and in all locations must contend with a wide diversity of predators including raptors and owls, mustelids, corvids, snakes, raccoons, opossums, skunks, turtles, large fish, felids, and canids, the last two including domestic cats and dogs.<ref>Template:Cite journal</ref> The most prolific natural predators of adult mallards are red foxes (Vulpes vulpes; which most often pick off brooding females) and the faster or larger birds of prey, (e.g. peregrine falcons, Aquila or Haliaeetus eagles).<ref name="NPWRC" /> In North America, adult mallards face no fewer than 15 species of birds of prey, from northern harriers (Circus hudsonius) and short-eared owls (Asio flammeus) (both smaller than a mallard) to huge bald (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos), and about a dozen species of mammalian predators, not counting several more avian and mammalian predators who threaten eggs and nestlings.<ref name=BNA/>
Mallards are also preyed upon by other waterside apex predators, such as grey herons (Ardea cinerea),<ref>Template:Cite journal</ref> great blue herons (Ardea herodias) and black-crowned night herons (Nycticorax nycticorax), the European herring gull (Larus argentatus), the wels catfish (Silurus glanis), and the northern pike (Esox lucius).<ref>Template:Cite book</ref> Crows (CorvusTemplate:NbspTemplate:Abbr) are also known to kill ducklings and adults on occasion.<ref>Template:Cite book</ref> Also, mallards may be attacked by larger anseriformes such as swans (CygnusTemplate:NbspTemplate:Abbr) and geese during the breeding season, and are frequently driven off by these birds over territorial disputes. Mute swans (Cygnus olor) have been known to attack or even kill mallards if they feel that the ducks pose a threat to their offspring.<ref>Template:Cite book</ref> Common loons (Gavia inmer) are similarly territorial and aggressive towards other birds in such disputes, and will frequently drive mallards away from their territory.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, in 2019, a pair of common loons in Wisconsin were observed raising a mallard duckling for several weeks, having seemingly adopted the bird after it had been abandoned by its parents.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
In summer, a combination of hot temperatures and reduced water levels place mallards at an increased risk of contracting botulism, as these conditions are ideal for Clostridium botulinum to propagate, with the birds also more likely to come into contact with botulinum toxin produced by the bacteria. Outbreaks of botulism among mallard populations can lead to mass die-offs.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The predation-avoidance behaviour of sleeping with one eye open, allowing one brain hemisphere to remain aware while the other half sleeps, was first demonstrated in mallards, although it is believed to be widespread among birds in general.<ref>Template:Cite journal</ref>
Status and conservationEdit
Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species. This is because it has a large range–more than Template:Cvt<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and because its population is increasing. Also, the population size of the mallard is very large.<ref name="IUCN"/>
Unlike many waterfowl, mallards have benefited from human alterations to the worldTemplate:Sndso much so that they are now considered an invasive species in some regions.<ref name=":8">Template:Cite journal</ref> They are a common sight in urban parks, lakes, ponds, and other human-made water features in the regions they inhabit, and are often tolerated or encouraged in human habitat due to their placid nature towards humans, their ducklings and their beautiful and iridescent colours.<ref name=":7" /> While most are not domesticated, mallards are so successful at coexisting in human regions that the main conservation risk they pose comes from the loss of genetic diversity among a region's traditional ducks once humans and mallards colonise an area. Mallards are very adaptable, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development.<ref>Template:Cite book</ref> The release of feral mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous waterfowl.<ref name=":8" /><ref name=":9" /> These non-migratory mallards interbreed with indigenous wild ducks from local populations of closely related species through genetic pollution by producing fertile offspring.<ref name=":9" /> Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl.<ref name=":9">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The mallard itself is the ancestor of most domestic ducks, and its naturally evolved wild gene pool gets genetically polluted in turn by the domestic and feral populations.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the speciation process is beginning to reverse itself.<ref name="Rhymer06" /> This has created conservation concerns for relatives of the mallard, such as the Hawaiian duck,<ref name="Rhymer96" /><ref name="Griffin" /> the New Zealand grey duck (A.Template:Nbsps. superciliosa) subspecies of the Pacific black duck,<ref name="Rhymer96" /><ref name="Williams" /> the American black duck,<ref name="Avise" /><ref name="Mank" /> the mottled duck,<ref name="McCracken" /> Meller's duck,<ref name="Young" /> the yellow-billed duck,<ref name="Rhymer06" /> and the Mexican duck,<ref name="Rhymer96" /><ref name="McCracken" /> in the latter case even leading to a dispute as to whether these birds should be considered a species<ref name="AOU" /> (and thus entitled to more conservation research and funding) or included in the mallard species. Ecological changes and hunting have also led to a decline of local species; for example, the New Zealand grey duck population declined drastically due to overhunting in the mid-20th century.<ref name="Williams" /> Hybrid offspring of Hawaiian ducks seem to be less well adapted to native habitat, and using them in re-introduction projects apparently reduces success.<ref name="Rhymer96" /><ref name="Kirby" /> In summary, the problems of mallards "hybridising away" relatives is more a consequence of local ducks declining than of mallards spreading; allopatric speciation and isolating behaviour have produced today's diversity of mallard-like ducks despite the fact that, in most, if not all, of these populations, hybridisation must have occurred to some extent.<ref>Template:Cite journal</ref>
- Mallard hybrids
- Wood Duck × Mallard imported from iNaturalist photo 182462006 on 3 December 2024.jpg
- Mallard × Muscovy Duck imported from iNaturalist photo 355013753 on 3 December 2024.jpg
- Mallard × American Wigeon imported from iNaturalist photo 27284228 on 3 December 2024.jpg
- Brewer's Duck imported from iNaturalist photo 364753928 on 3 December 2024 (cropped).jpg
- Mallard × Eurasian Wigeon imported from iNaturalist photo 450807057 on 3 December 2024.jpg
- Mallard × Red-crested Pochard imported from iNaturalist photo 423714582 on 3 December 2024.jpg
- Mallard × Ruddy Shelduck imported from iNaturalist photo 356571403 on 3 December 2024 (cropped).jpg
- Mallard × Northern Pintail imported from iNaturalist photo 26297743 on 3 December 2024 (cropped).jpg
x A. acuta
- Hybrid Anas carolinensis × Anas platyrhynchos, Dallas, Texas.jpg
- Mallard × Mexican Duck imported from iNaturalist photo 351774358 on 3 December 2024.jpg
x A. diazi
- Mallard × Mottled Duck imported from iNaturalist photo 111437277 on 3 December 2024 (cropped).png
- Pacific Black Duck × Mallard imported from iNaturalist photo 324966462 on 3 December 2024.jpg
- American Black Duck × Mallard imported from iNaturalist photo 249600327 on 3 December 2024.jpg
- Mallard × Yellow-billed Duck imported from iNaturalist photo 251718983 on 3 December 2024 (cropped).jpg
- Mallard × Eastern Spot-billed Duck imported from iNaturalist photo 251491647 on 3 December 2024 (cropped).jpg
InvasivenessEdit
Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks<ref name="krugerpark.co.za" /> even though the Agreement on the Conservation of African-Eurasian Migratory Waterbirds – an agreement to protect the local waterfowl populations – applies to the mallard as well as other ducks.<ref>{{#invoke:citation/CS1|citation
|CitationClass=web }}</ref> The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring.<ref name=":4">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> If this continues, only hybrids occur and in the long term result in the extinction of various indigenous waterfowl.<ref name=":4" /> The mallard can crossbreed with 63 other species, posing a severe threat to indigenous waterfowl's genetic integrity.<ref>Template:Cite news</ref> Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food.<ref name=krugerpark.co.za/> Availability of mallards, mallard ducklings, and fertilised mallard eggs for public sale and private ownership, either as poultry or as pets, is currently legal in the United States, except for the state of Florida, which has currently banned domestic ownership of mallards. This is to prevent hybridisation with the native mottled duck.<ref name=myfwc2/>
The mallard is considered an invasive species in Australia and New Zealand,Template:R where it competes with the Pacific black duck (known as the grey duck locally in New Zealand) which was over-hunted in the past. There, and elsewhere, mallards are spreading with increasing urbanisation and hybridising with local relatives.<ref name="Rhymer96" />
The eastern or Chinese spot-billed duck is currently introgressing into the mallard populations of the Primorsky Krai, possibly due to habitat changes from global warming.<ref name="Kulikova et al. 2004" /> The Mariana mallard was a resident allopatric population – in most respects a good species – apparently initially derived from mallard-Pacific black duck hybrids;<ref name=Yamashina/> it became extinct in the late 20th century.<ref name=MadgeWildfowl>Template:Cite book</ref>
The Laysan duck is an insular relative of the mallard, with a very small and fluctuating population.<ref>Template:Cite journal</ref><ref name="IUCN" /> Mallards sometimes arrive on its island home during migration, and can be expected to occasionally have remained and hybridised with Laysan ducks as long as these species have existed.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, these hybrids are less well adapted to the peculiar ecological conditions of Laysan Island than the local ducks, and thus have lower fitness. Laysan ducks were found throughout the Hawaiian archipelago before 400Template:NbspAD, after which they suffered a rapid decline during the Polynesian colonisation.<ref name=":21">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Now, their range includes only Laysan Island.<ref name=":21" /> It is one of the successfully translocated birds, after having become nearly extinct in the early 20th century.<ref>Template:Cite book</ref>
Relationship with humansEdit
DomesticationEdit
Mallards have often been ubiquitous in their regions among the ponds, rivers, and streams of human parks, farms, and other human-made waterwaysTemplate:Sndeven to the point of visiting water features in human courtyards.<ref>Template:Cite book</ref>
Mallards have had a long relationship with humans. Almost all domestic duck breeds derive from the mallard, with the exception of a few Muscovy breeds,<ref>Template:Cite book</ref> and are listed under the trinomial name A. p. domesticus. Mallards are generally monogamous while domestic ducks are mostly polygamous. Domestic ducks have no territorial behaviour and are less aggressive than mallards.<ref name=":23">Template:Cite book</ref> Domestic ducks are mostly kept for meat; their eggs are also eaten, and have a strong flavour.<ref name=":23" /> They were first domesticated in Southeast Asia at least 4,000 years ago, during the Neolithic Age, and were also farmed by the Romans in Europe, and the Malays in Asia.<ref>Template:Cite book</ref> As the domestic duck and the mallard are the same species as each other, it is common for mallards to mate with domestic ducks and produce hybrid offspring that are fully fertile.<ref name=":22">Template:Cite book</ref> Because of this, mallards have been found to contain genes of the domestic duck.<ref name=":22" />
While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> although they may require wing clipping to restrict flying.
HuntingEdit
Mallards are one of the most common species shot in waterfowl hunting due to their large population size. The ideal location for hunting mallards is considered to be where the water level is somewhat shallow where the birds can be found foraging for food.<ref>Template:Cite book</ref> Hunting mallards might cause the population to decline in some places, at some times, and with some populations.<ref>Template:Cite book</ref> In certain countries, the mallard may be legally shot but is protected under national acts and policies. For example, in the United Kingdom, the mallard is protected under the Wildlife and Countryside Act 1981, which restricts certain hunting methods or taking or killing mallards.<ref>Template:Cite book</ref>
Mallard-vehicle collisionsEdit
Template:Further Since standardized data collection began in 1990, the United States Federal Aviation Administration has recorded 1320 mallard collisions with aircraft, 261 of which caused damage to the craft (through 2022).<ref name=":0">Template:Cite book</ref> In the United States, the mallard ranks as the 7th most hazardous bird to both military and commercial aircraft.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> Mallards are of particular concern due to their ubiquity; they are widespread and adaptable to urban environments.<ref>Template:Cite journal</ref><ref name=":5">Template:Cite journal</ref> Mallards also generally fail to avoid approaching vehicles in experimental settings, especially at high vehicle speeds.<ref name=":5" />
Though most bird strikes occur during the takeoff and landing phases of flight,<ref name=":0" /> at least one mallard has been struck at cruising altitude (21,000 feet).<ref>Template:Cite journal</ref>
As foodEdit
Since ancient times, the mallard has been eaten as food. The wild mallard was eaten in Neolithic Greece.<ref>Template:Cite book</ref> Usually, only the breast and thigh meat is eaten.<ref>Template:Cite book</ref> It does not need to be hung before preparation, and is often braised or roasted, sometimes flavoured with bitter orange or with port.<ref>Template:Cite book</ref>
In cultureEdit
Make Way for Ducklings is a children's picture book written and illustrated by Robert McCloskey. The book centers on a pair of mallards who raise their ducklings in the Boston Public Garden.<ref>Template:Cite book</ref>
Migration is an animated adventure comedy film produced by Universal Pictures and Illumination. The story follows a family of mallards who try to migrate from New England to Jamaica.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The world's loneliest duck, named "Trevor" by locals after New Zealand politician Trevor Mallard, appeared without explanation on the Pacific island of Niue, dying there in 2019.
ReferencesEdit
External linksEdit
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