Mallard

The mallard was one of the many bird species originally described in the 1758 10thedition of Systema Naturae by Carl Linnaeus. The latter was generally preferred until 1906 when Einar Lönnberg established that A.platyrhynchos had priority, as it appeared on an earlier page in the text. The scientific name comes from Latin Anas, "duck" and Ancient Greek πλατυρυγχος, platyrhynchus, "broad-billed" (from πλατύς, platys, "broad" and ρυγχός, rhunkhos, "bill"). The genome of Anas platyrhynchos was sequenced in 2013. It was derived from the Old French ' or ' for "wild drake" although its true derivation is unclear. It may be related to, or at least influenced by, an Old High German masculine proper name '''', clues lying in the alternative English forms "maudelard" and "mawdelard". 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. though fertile hybrids typically have two Anas parents. Mallards and their domestic conspecifics are fully interfertile; many wild mallard populations in North America contain significant amounts of domestic mallard DNA. Genetic analysis has shown that certain mallards appear to be closer to their Indo-Pacific relatives, while others are related to their American relatives. Mallards are differentiated in their mitochondrial DNA between North American and Eurasian populations, Subspecies Two subspecies are currently accepted: In the past, several other ducks, now treated as distinct species, were sometimes treated as subspecies of mallard: • Laysan duck Anas laysanensis • Hawaiian duck Anas wyvilliana • Mottled duck Anas fulvigula • American black duck Anas rubripes • Mexican duck Anas diazi ==Description==

The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. It is longof which the body makes up around two-thirdshas a wingspan of , and weighs . The rear of the male is black, with white-bordered dark tail feathers. 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. 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. Mallards, like other sexually-dimorphic birds, can sometimes go through spontaneous sex reversal, often caused by damaged or nonfunctioning sex organs, such as the ovaries. This phenomenon can cause female mallards to exhibit male plumage. 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. 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. Its legs and bill are also black. 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)the bill is yellow in males, but black and orange in females; 2)the breast feathers are reddish-brown in males, but brown in females; 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. 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. More similar to the female mallard in North America are the American black duck (A.rubripes), which is notably darker-hued in both sexes than the mallard, and the mottled duck (A.fulvigula), which is somewhat darker than the female mallard, and with slightly different bare-part colouration and no white edge on the speculum. The female pictured here is leucistic; leucism in birds often results in 'cream-coloured', 'apricot' or muted feathers on certain parts of the body. In captivity, domestic ducks come in wild-type plumages, white, and other colours. 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. Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds, as in case of the Greenland mallard which is larger than the mallards further south. 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, and, as in the Greenland mallard, the bill is smaller than that of birds farther south, illustrating the rule. 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. 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. 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. == Distribution and habitat ==

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, across the Palearctic, from Iceland and southern Greenland Japan, and South Korea. and New Zealand in the Southern Hemisphere. For example, in North America, it winters south to the southern United States and northern Mexico, but also regularly strays into Central America and the Caribbean between September and May. A drake later named "Trevor" attracted media attention in 2018 when it turned up on the island of Niue, an atypical location for mallards. The mallard inhabits a wide range of habitats and climates, from the Arctic tundra to subtropical regions. 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. Water depths of less than are preferred, with birds avoiding areas more than a few metres deep. They are attracted to bodies of water with aquatic vegetation. ==Behaviour==

availability, and interspecific and intraspecific competition. insects (including beetles, flies, lepidopterans, dragonflies, and caddisflies), crustaceans, other arthropods, worms, many varieties of seeds and plant matter, In 2026, this behaviour was also observed in New Zealand's Lake Alexandrina, with mallards observed preying upon the chicks of the pūteketeke and subsequently euthanised. 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". File:Mallard duck eating bread.jpg|Eating bread File:Fish-Eating Mallard.jpg|Eating a small fish File:Duck eating a Fish (5979923772).jpg|Eating a larger fish File:Mallard drake eating leopard frog Sand Lake WMD (14822335555).jpg|Eating a frog Breeding 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. 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). 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) 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. File:Anas platyrhynchos MWNH 1048.JPG|Egg File:Mallard and ducklings - geograph.org.uk - 4473798.jpg|Young ducklings File:Mallard ducklings (3752889877).jpg|Older ducklings File:Duckling in Central Park (81320).jpg|Moulting File:Anas platyrhynchos juvenile JdP 2013-06-14 n01 retusche.jpg|Fledgling female and male File: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, 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. Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles. They measure about in length and in width. The ducklings are precocial and fully capable of swimming as soon as they hatch. 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. 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. 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. 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. During the breeding season, both male and female mallards can become aggressive, driving off competitors to themselves or their mate by charging at them. 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. It is possible that this behaviour allows the female to evaluate the strength of potential partners. 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. Lebret (1961) calls this behaviour "Attempted Rape Flight", and Stanley Cramp and K.E.L. Simmons (1977) speak of "rape-intent flights". 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. 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. ==Predators and threats==

(Cygnus olor) driving off a female mallard. 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. 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). 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). Crows (Corvus) are also known to kill ducklings and adults on occasion. Also, mallards may be attacked by larger anseriformes such as swans (Cygnus) 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. Common loons (Gavia inmer) are similarly territorial and aggressive towards other birds in such disputes, and will frequently drive mallards away from their territory. 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. 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. 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. == Status and conservation ==

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 , though its very large population – estimated at more than 17 million mature individuals as of 2025 – is decreasing. 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. The release of feral mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous waterfowl. 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. Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the speciation process is beginning to reverse itself. File:Wood Duck × Mallard imported from iNaturalist photo 182462006 on 3 December 2024.jpg|x Aix sponsa File:Mallard × Muscovy Duck imported from iNaturalist photo 355013753 on 3 December 2024.jpg|x Cairina moschata File:Mallard × American Wigeon imported from iNaturalist photo 27284228 on 3 December 2024.jpg|x Mareca americana File:Brewer's Duck imported from iNaturalist photo 364753928 on 3 December 2024 (cropped).jpg|x Mareca strepera (Brewer's duck) File:Mallard × Eurasian Wigeon imported from iNaturalist photo 450807057 on 3 December 2024.jpg|x Mareca penelope File:Mallard × Red-crested Pochard imported from iNaturalist photo 423714582 on 3 December 2024.jpg|x Netta rufina File:Mallard × Ruddy Shelduck imported from iNaturalist photo 356571403 on 3 December 2024 (cropped).jpg|x Tadorna ferruginea File:Mallard × Northern Pintail imported from iNaturalist photo 26297743 on 3 December 2024 (cropped).jpg|x A. acuta File:Hybrid Anas carolinensis × Anas platyrhynchos, Dallas, Texas.jpg|x A. carolinensis File:Mallard × Mexican Duck imported from iNaturalist photo 351774358 on 3 December 2024.jpg|x A. diazi File:Mallard × Mottled Duck imported from iNaturalist photo 111437277 on 3 December 2024 (cropped).png|x A. fulvigula File:Pacific Black Duck × Mallard imported from iNaturalist photo 324966462 on 3 December 2024.jpg|x A. superciliosa File:20241229 american black duck mallard hybrid beaver brook open space PD209221.jpg|x A. rubripes File:Mallard × Yellow-billed Duck imported from iNaturalist photo 251718983 on 3 December 2024 (cropped).jpg|x A. undulata File:Mallard × Eastern Spot-billed Duck imported from iNaturalist photo 251491647 on 3 December 2024 (cropped).jpg|x A. zonorhyncha Invasiveness Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring. If this continues, only hybrids occur and in the long term result in the extinction of various indigenous waterfowl. Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food. The Laysan duck is an insular relative of the mallard, with a very small and fluctuating population. 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 400AD, after which they suffered a rapid decline during the Polynesian colonisation. Now, their range includes only Laysan Island. == Relationship with humans ==

Domestication , a breed of domestic duck derived from the mallard Mallards have often been ubiquitous in their regions among the ponds, rivers, and streams of human parks, farms, and other human-made waterwayseven to the point of visiting water features in human courtyards. 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, 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. Domestic ducks are mostly kept for meat; their eggs are also eaten, and have a strong flavour. 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. Because of this, mallards have been found to contain genes of the domestic duck. although they may require wing clipping to restrict flying. Hunting , mallard still life painting, 1883–1884 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. Hunting mallards might cause the population to decline in some places, at some times, and with some populations. 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. Mallard–vehicle collisions 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). In the United States, the mallard ranks as the 7th most hazardous bird to both military and commercial aircraft. Mallards are of particular concern due to their ubiquity; they are widespread and adaptable to urban environments. Mallards also generally fail to avoid approaching vehicles in experimental settings, especially at high vehicle speeds. As food Since ancient times, the mallard has been eaten as food. The wild mallard was eaten in Neolithic Greece. Usually, only the breast and thigh meat is eaten. It does not need to be hung before preparation, and is often braised or roasted, sometimes flavoured with bitter orange or with port. In culture 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. Migration is an animated adventure comedy film produced by Universal Pictures and Illumination. The story follows a family of mallards that live in a pond in New England and go on vacation in Jamaica. 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. == Footnotes ==