mallard duck classification

Almost all domestic duck breeds derive from the mallard, with the exception of a few Muscovy breeds,[125] and are listed under the trinomial name A. p. domesticus. [84] It is possible that this behaviour allows the female to evaluate the strength of potential partners. 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. [134] Usually, only the breast and thigh meat is eaten. Domestic ducks have no territorial behaviour and are less aggressive than mallards. It has a brown chest, a whitish-gray underside, brown wings and a yellow bill. Large dabbling duck weighing up to 1.3 kg; In breeding plumage, drake (also known as a ‘greenhead’) is easily identified by bright green head, olive yellow bill, … [103][111] 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. MALLARD DUCK (Anas platyrhynchos) General Characteristics: Mallard males and females look different. Its wide range has given rise to several distinct populations. It is part of the species of Dabbling Ducks. ", "Bergmann's and Allen's Rules in Native European and Mediterranean Phasmatodea", "A test of Allen's rule in ectotherms: the case of two south American Melanopline Grasshoppers (Orthoptera: Acrididae) with partially overlapping geographic ranges", "Trevor the lonely duck gets tiny island of Niue in a flap", "Mallard Duck • Elmwood Park Zoo | Elmwood Park Zoo | www.elmwoodparkzoo.org", "Flexibility of Continental Navigation and Migration in European Mallards", "Foods consumed by breeding mallards on wetlands of south-central North Dakota", "Wild ducks caught on camera snacking on small birds", "Vocalizations of the Mallard (Anas Platyrhynchos)", "Female mate preferences and subsequent resistance to copulation in the mallard", "The first case of homosexual necrophilia in the mallard Anas platyrhynchos (Aves:Anatidae)", "Impact of Red Fox Predation on the Sex Ratio of Prairie Mallards", "The evolutionary impact of invasive species", "Hawaiian Duck's Future Threatened by Feral Mallards", "Extinction by hybridization and introgression in anatine ducks", "Mitochondrial gene trees and the evolutionary relationship of Mallard and Black Ducks", "Haldane's rule and American black duck × mallard hybridization", "Hybridization patterns and the evolution of reproductive isolation in ducks", "Invasive Alien Bird Species Pose A Threat, Kruger National Park, Siyabona Africa Travel (Pty) Ltd – South Africa Safari Travel Specialist", "Agreement on the Conservation of African-Eurasian Migratory Waterbirds", "Those mighty mallards can bust the speed limit", Florida Fish and Wildlife Conservation Commission, "Recovery Strategy – Laysan Duck Revised Recovery Plan", "Raising Mallard Ducks: How to Raise Mallards In Your Backyard Duck Yard – DuckHobby.com", British Association for Shooting and Conservation, Hunting and shooting in the United Kingdom, https://en.wikipedia.org/w/index.php?title=Mallard&oldid=1011090851, Native birds of the Eastern United States, Articles with self-published sources from December 2017, Articles with unsourced statements from February 2019, Articles with unsourced statements from August 2017, Creative Commons Attribution-ShareAlike License, This page was last edited on 8 March 2021, at 23:42. Mallard are all members that will produce fertile 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. [96], Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species. [56][57], The mallard inhabits a wide range of habitats and climates, from Arctic tundra to subtropical regions. [21], The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. Mallard duck is 50 to 65 cm long and has a wingspan of 81 to 98 cm. The mallard is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN). [89], Mallards are also preyed upon by other waterside apex predators, such as the grey heron (Ardea cinerea),[92] European herring gull (Larus argentatus), the wels catfish (Silurus glanis), and the northern pike (Esox lucius). amniotic eggs. The second phylogenetic tree is based on morphological features [28] 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. a post-anal tail. [43], 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,[44] across the Palearctic,[45] from Iceland[46] and southern Greenland[44] and parts of Morocco (North Africa)[46] in the west, Scandinavia[46] and Britain[46] to the north, and to Siberia,[47] Japan,[48] and South Korea. [132] In certain countries, the mallard may be legally shot but is protected under national acts and policies. The mallard duck is the most adaptable of all ducks and is well dispersed throughout North America. The mallard is a legal gamebird that is hunted during the annual May-June waterfowl season. Mallards will feed both during the day and at night, although during the hunting season, they will likely eat under the cover of darkness and … The most common dabbling duck species is the mallard, but the northern pintail, American wigeon, and different teals are also dabblers. - Members of this group do not posses cells [126] 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. The mallard (Anas platyrhynchos) is the most common and widely distributed dabbling duck, having a widespread global distribution throughout the northern hemisphere.This migratory species is a highly valued game bird and the source of all domestic ducks with the exception of the Muscovy. [85], 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. [91] 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 predator, not counting several more avian and mammalian predators who threaten eggs and nestlings. Some examples of Mallard hybrids: American Black Duck, Gadwall, Cinnamon Teal, Hawaiian ducks and the Pacific Black Duck; Oldest male Mallard duck to date was 27 years and 7 months old when he was shot in Arkansas in 2008. the mallard duck, but not as you remember it. [6], The name Mallard originally referred to any wild drake, and it is sometimes still used this way. [39] Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds,[40] as in case of the Greenland mallard which is larger than the mallards further south. Appearance. It has a long body, and a long and broad bill. Incubation takes 27 to 28 days and fledging takes 50 to 60 days. [18] Haplotypes typical of American mallard relatives and eastern spot-billed ducks can be found in mallards around the Bering Sea. Male and female mallard ducks have drastically different colorations. The speculum is violet-blue bordered by black and white, and the outer tail feathers are white. [77][78] They measure about 58 mm (2.3 in) in length and 32 mm (1.3 in) in width. 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. [113], 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. feathers on its head, and a narrow white collar band. Species: platyrhynchos Mallard duck inhabits mainly northern hemisphere and it can be found in North America, Europe and Asia. - All members are winged, bipedal (two The ducklings are precocial and fully capable of swimming as soon as they hatch. 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;[30][self-published source] 2) the breast feathers are reddish-brown in males, but brown in females;[30] and 3) in males, the centre tail feather (drake feather) is curled, but in females, the centre tail feather is straight. [99][101] These non-migratory mallards interbreed with indigenous wild ducks from local populations of closely related species through genetic pollution by producing fertile offspring. Domain: Eukarya - All There are over 60 subspecies that have been identified. mallard: see duck duck, common name for wild and domestic waterfowl of the family Anatidae, which also includes geese and swans. underwater to obtain food in muddy or debris-filled water. - One of the most recognizable waterfowl in Genus: Anas - Members of this group are the dabbling to have a flattened bill that contain lamellae. 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. While most mallards breed on the northern prairies, many nest elsewhere, including North Carolina. Mallard mature rapidly and … 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. [24], The breeding male mallard is unmistakable, with a glossy bottle-green head and a white collar that demarcates the head from the purple-tinged brown breast, grey-brown wings, and a pale grey belly. Although the mallard prefers shallow wetlands for feeding and resting, it builds its nest on dry ground. [3] 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. [112], Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks[113] 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. [98], Unlike many waterfowl, mallards have benefited from human alterations to the world – so much so that they are now considered an invasive species in some regions. Kingdom: Animalia [31] The adulthood age for mallards is fourteen months, and the average life expectancy is three years, but they can live to twenty. [35] 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. [33] 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. They have a wingspan that ranges from 32 to 39 inches. [77][79] The ducklings are precocial and fully capable of swimming as soon as they hatch. [88] 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. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae. their life cycle, and are multi-cellular. [90] The most prolific natural predators of adult mallards are red foxes (which most often pick off brooding females) and the faster or larger birds of prey, e.g. 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. Most Mallards tend to have quite a large appetite. [22]:506 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. members have cell(s) which posses a nucleus and membrane bound [19] The Mariana mallard was a resident allopatric population – in most respects a good species – apparently initially derived from mallard-Pacific black duck hybrids;[118] unfortunately, it became extinct in the late twentieth century. Duck. [22]:506 Two months after hatching, the fledgling period has ended, and the duckling is now a juvenile. aquatic environments. He gave it two binomial names: Anas platyrhynchos and Anas boschas. [67][68], The mallard usually feeds by dabbling for plant food or grazing; there are reports of it eating frogs. [15] 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. amniotic eggs. Mallard Duck Identification and Life history. The final column that includes the The male has a dark green head, a yellow bill, is mainly purple-brown on the breast and grey on the body. [86] Lebret (1961) calls this behaviour "Attempted Rape Flight", and Stanley Cramp and K.E.L. The scientific name comes from Latin Anas, "duck" and Ancient Greekπλατυρυγχος, platyrhynchus, "broad-billed" (from πλατύς, platys, "broad" and ρυγχός, … During the first 2 years of the study, hunters shot considerably more birds than subsequent years (Fig. [126] Domestic ducks are mostly kept for meat; their eggs are also eaten, and have a strong flavour. The mallard is one of the most recognized of all ducks and is the ancestor of several domestic breeds. A. p. platyrhynchos Linnaeus, 1758 The Mallard duck is classed as a medium sized duck. Both sexes have an area of white-bordered black or iridescent blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. [55] A drake later named "Trevor" attracted media attention in 2018 when it turned up on the island of Niue, an atypical location for mallards. A. p. conboschas C. L. Brehm, 1831 (disputed). A. p. domesticus Linnaeus, 1758 their life cycle, and are multi-cellular. a post-anal tail. This recently reopened oasis tempts its friends to indulge in a shares style fare while relishing our … Family: Anatidae Mallard. The male mallard has a green head and neck with a white ring bordering it. [30] 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. Birders who can easily identify mallards—males, females, eclipse males, and mallards in flight—can use that expertise to quickly identify what birds are, and aren't, mallards in the field, making duck … The wingspan is 81–98 cm (32–39 in) and the bill is 4.4 to 6.1 cm (1.7 to 2.4 in) long. Also, the population size of the mallard is very large. [25] The rear of the male is black, with white-bordered dark tail feathers. - Members have a skeletal rod (notochord), [26] 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. [27] 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. [95], 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. [5] The genome of Anas platyrhynchos was sequenced in 2013. feet), reproduce sexually with internal fertilization and lay [29] Between three and four months of age, the juvenile can finally begin flying, as its wings are fully developed for flight (which can be confirmed by the sight of purple speculum feathers). [86] This paper was awarded an Ig Nobel Prize in 2003. Mallard pair. tree is based in part on morphological features, but also on This maternal vocalisation is highly attractive to their young. Animals within this group include ducks, The mallard was one of the many bird species originally described in the 1758 10th edition of Systema Naturae by Carl Linnaeus. - All members are winged, bipedal (two [120][1] 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. [32], Several species of duck have brown-plumaged females that can be confused with the female mallard. The Mallard is omnivorous, feeding on anything from nuts, fruits, rice, Sweet Corn, and other types of grain, to small fish, snails, worms, and even flies. the feathers that repel water. [23] Among standard measurements, the wing chord is 25.7 to 30.6 cm (10.1 to 12.0 in), the bill is 4.4 to 6.1 cm (1.7 to 2.4 in), and the tarsus is 4.1 to 4.8 cm (1.6 to 1.9 in). [70] It usually nests on a river bank, but not always near water. ©DUC. [116] Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food. - Members of this group have fully webbed feet [103], 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. offspring if mated with the Mallard. Mallards are the most familiar and most widespread dabbling duck in the world, and knowing how to properly identify these ducks is the key to understanding the identification of all ducks, including picking out the mallard clues in hybrid ducks. Female mallards, simply known as “ducks,” or “hens,” are much more demure in coloration. [60] They are attracted to bodies of water with aquatic vegetation. [34], In captivity, domestic ducks come in wild-type plumages, white, and other colours. The bill is yellow to yellowish-green and the legs and feet are coral-red. Mallard duck (also known as wild duck) is the largest and the most abundant duck in the world. [13], Genetic analysis has shown that certain mallards appear to be closer to their Indo-Pacific relatives while others are related to their American relatives. [94] Also, mallards may be attacked by larger anseriformes such as swans (Cygnus spp.) [65] 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. The animals in this family tend Mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes. Class: Aves The third Regional Differences. geese, swans, and relatives (screamers and magpie goose). geese, swans, and relatives (screamers and magpie goose). These birds are the most abundant and widely distributed duck species in North America. The Mariana mallard or Oustalet's duck (Anas oustaleti) is an extinct type of duck of the genus Anas that was endemic to the Mariana Islands. The mallard (/ˈmælɑːrd, ˈmælərd/) (Anas platyrhynchos) is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. Wild Mallards will eat and drink as needed or as available to them. [citation needed] 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. The scientific name for the Mallard Duck is Anas Platyrhynchos. [80] 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. [12] Mallards and their domesticated conspecifics are also fully interfertile. [93] Crows (Corvus spp.) [136], Game animals and shooting in North America, International Union for Conservation of Nature, Agreement on the Conservation of African-Eurasian Migratory Waterbirds, "Anas platyrhynchos (Common Mallard, Mallard, Northern Mallard)", "Evolutionary relationships among the North American mallards", "The duck genome and transcriptome provide insight into an avian influenza virus reservoir species", "Experimental studies of hybridization among ducks and pheasants", "Late Pleistocene Birds from Kingston Saltpeter Cave, Southern Appalachian Mountains, Georgia", "Phylogeny and biogeography of dabbling ducks (genus, 10.1642/0004-8038(2005)122[0949:POTMAP]2.0.CO;2, 10.1642/0004-8038(2005)122[1309:POTMAP]2.0.CO;2, "Evolution and connectivity in the world-wide migration system of the mallard: Inferences from mitochondrial DNA", 10.1642/0004-8038(2004)121[0930:AHASGF]2.0.CO;2, "Phylogenetics of a recent radiation in the mallards and allies (Aves: Anas): inferences from a genomic transect and the multispecies coalescent", "Global warming and Bergmann's rule: do central European passerines adjust their body size to rising temperatures? When taking off, the wings of a mallard produce a characteristic faint whistling noise. [19] The Aleutian Islands hold a population of mallards that appear to be evolving towards a subspecies, as gene flow with other populations is very limited. [87], 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. [citation needed], Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the speciation process is beginning to reverse itself. Mallard Ducks are included in the family Anatidae and subfamily Anatinae. - Members of this group do not posses cells Both males and females closely resemble female Mallards, although the body color is somewhat darker than a typical female Mallard. with cell walls, they are heterotrophic (they feed on other The mallard is a large and heavy looking duck. The females are tan and brown with a blue mark on the wings. The male has the very distinctive iridescent green [21], 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). things for nutrient uptake), they are motile at some stage in [22]:507 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. - All The female lays eight to thirteen creamy white to greenish-buff spotless eggs, on alternate days. aquatic environments. [27] 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. [119], The Laysan duck is an insular relative of the mallard, with a very small and fluctuating population. Animals within this group include ducks, The money generated by duck hunting license fees pays for the management of Mallard populations, and those of other ducks, and is used to protect important habitats. Mallard Ducks enjoy the water and usually are found near rivers, ponds, or other bodies of water. Mallard Duck Characteristics. - Members of this group have fully webbed feet [22]:506, 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. [86] Male mallards also occasionally chase other male ducks of a different species, and even each other, in the same way. 02 of 12. [78] Incubation takes 27–28 days and fledging takes 50–60 days. Mallards frequently interbreed with their species in the genus Anas, such as American Black Duck (Anas rubripes), Florida Duck (A. fulvigula) and others producing hybrids that may be fully fertile with variations in plumage color as well as behavioral characteristics. [128], While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat,[129] although they may require wing clipping to restrict flying, or training to navigate and fly home. Mallard Ducks are a noisy species. [66] Plants generally make up the larger part of a bird's diet, especially during autumn migration and in the winter. As a rule of thumb, more decoys and higher quality decoys the higher the success rate, especially when hunting large flocks of … Not to add more issues, mallards have had offspring with almost every species of North American duck. [75][76], Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles. [59] Water depths of less than 0.9 metres (3.0 ft) are preferred, with birds avoiding areas more than a few metres deep. [10], 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. [51][52] For example, in North America, it winters south to the southern United States and northern Mexico,[53][54] but also regularly strays into Central America and the Caribbean between September and May. [114] The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring. [100] The release of feral mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous waterfowl. This is to prevent hybridisation with the native mottled duck. It is 50–65 cm (20–26 in) long – of which the body makes up around two-thirds – has a wingspan of 81–98 cm (32–39 in),[22]:505 and weighs 0.7–1.6 kg (1.5–3.5 lb). There, and elsewhere, mallards are spreading with increasing urbanisation and hybridising with local relatives. [105] Hybrid offspring of Hawaiian ducks seem to be less well adapted to native habitat, and using them in re-introduction projects apparently reduces success. are also known to kill ducklings and adults on occasion. 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. [48] Also in the east, it ranges to south-eastern and south-western Australia[49] and New Zealand[50] in the Southern hemisphere. Mallard hunting over the water is the traditional method of hunting. [22]:507, The mallard is omnivorous and very flexible in its choice of food. The female is mainly brown with an orange bill. members have cell(s) which posses a nucleus and membrane bound Strictly speaking, duck refers to the female and drake to the male..... Click the link for more information.. [123], Mallards have often been ubiquitous in their regions among the ponds, rivers, and streams of human parks, farms, and other human-made waterways – even to the point of visiting water features in human courtyards. feet), reproduce sexually with internal fertilization and lay It is highly gregarious outside of the breeding season and forms large flocks, which are known as "sordes. Th… conboschas). Unlike many waterfowl, mallards are considered an invasive species in some regions. [7] It was derived from the Old French malart or mallart for "wild drake" although its true derivation is unclear. This species is the main ancestor of most breeds of domesticated ducks. [133], Since ancient times, the mallard has been eaten as food. The brown-speckled plumage is mostly found in the female Mallard Ducks. [37] In addition, females hiss if the nest or offspring are threatened or interfered with. and geese during the breeding season, and are frequently driven off by these birds over territorial disputes. Breeding. similarities in DNA. In many places this species has managed to domesticate itself, relying on handouts in city parks. endostyle (thyroid gland), pharyngeal pouches at some stage, and The repetition and frequency modulation of these quacks form the auditory basis for species identification in offspring, a process known as acoustic conspecific identification. Simmons (1977) speak of "rape-intent flights". [20], 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. p.