Gadwall | |
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Female | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Anseriformes |
Family: | Anatidae |
Genus: | Mareca |
Species: | M. strepera |
Binomial name | |
Mareca strepera | |
Subspecies | |
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Synonyms | |
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The gadwall (Mareca strepera) is a common and widespread dabbling duck [2] in the family Anatidae.
The gadwall was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. [3] DNA studies have shown that it is a sister species with the falcated duck; the two are closely related to the three species of wigeons, and all of them have been assigned to the genus Mareca . [4] [5] There are two subspecies: [6]
The specific name strepera is Late Latin for "noisy". [8] The etymology of the word gadwall is not known, but the name has been in use since 1666. [9]
The gadwall is 47–58 cm (19–23 in) long with a 78–85 cm (31–33 in) wingspan. [10] The male is slightly larger than the female, weighing on average 990 g (35 oz) against her 850 g (30 oz). [11] The breeding male is patterned grey, with a black rear end, light chestnut wings, and a brilliant white speculum, obvious in flight or at rest. [12] In non-breeding (eclipse) plumage, the drake looks more like the female, but retains the male wing pattern, and is usually greyer above and has less orange on the bill. [11]
The female is light brown, with plumage much like a female mallard. It can be distinguished from that species by the dark orange-edged bill, smaller size, the white speculum, and white belly. [12] Both sexes go through two moults annually, following a juvenile moult. [10]
The gadwall is a quieter duck, except during its courtship display. Females give a call similar to the quack of a female mallard but higher-pitched, transcribed as gag-ag-ag-ag. Males give a grunt, transcribed as mep, and a whistle. [11]
The gadwall breeds in the northern areas of Europe and across the Palearctic, and central North America. In North America, its breeding range lies along the Saint Lawrence River, through the Great Lakes, Alberta, Saskatchewan, the Dakotas, south to Kansas, west to California, and along coastal Pacific Canada and southern coastal Alaska. [10] [12] The range of this bird appears to be expanding into eastern North America. This dabbling duck is strongly migratory, and winters farther south than its breeding range, from coastal Alaska, south into Central America, and east into Idaho, Kansas, Ohio, Virginia, and then south all the way into Central America. [10] [12]
In Great Britain, the gadwall is a scarce-breeding bird and winter visitor, though its population has increased in recent years. It is likely that its expansion was partly through introduction, mainly to England, and partly through colonization by continental birds staying to breed in Scotland. In Ireland a small breeding population has recently become established, centred on County Wexford in the south and Lough Neagh in the north. [13] The Gadwall is also seen in some parts of South Asia, particularly the southern part of India. [14]
The gadwall is a bird of open wetlands, such as prairie or steppe lakes, wet grassland or marshes with dense fringing vegetation, and usually feeds by dabbling for plant food with head submerged. They can also dive underwater for food, more proficiently than other dabbling ducks, and may also steal food from diving birds such as coots. [15] It nests on the ground, often some distance from water. It is not as gregarious as some dabbling ducks outside the breeding season and tends to form only small flocks.
Gadwalls are monogamous and may start breeding after their first year. Pair formation begins during fall migration or on breeding grounds, but has also been reported to occur in August when males are still in eclipse plumage. Gadwalls are generally quiet, except during courtship. The male utters a mep call during a display known as the burp, where he raises his head pointing his bill towards a female. [16] The grunt-whistle is similar to that of mallards, where the male rears his outstretched head with the bill dipped into water, displacing a stream of water droplets towards a nearby female as the bill is raised against the chest. During this display the male makes a loud whistle call followed by a low burp. [17] Paired males may follow other females in flight displays. [15] [18]
During nesting season, the female lays a clutch of 7-12 eggs with each of them measuring 4.9–6 cm (1.9–2.4 in) in length and 3.4–4.4 cm (1.3–1.7 in) in width. Incubation lasts for 24-27 days and the nestlings leave after around 1-2 days. A gadwall can only raise one brood a season [2]
Currently, the gadwall is listed as least concern in the IUCN Red List of Threatened Species. [1] The gadwall is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. Populations have increased approximately 2.5% over the course of 49 years (from 1966 to 2010), and continue to grow. Gadwalls are one of the most hunted duck species (3rd to the mallard and green-winged teal), with 1.7 million shot each year. [19]
Because of the efforts of the United States and Canadian groups Ducks Unlimited, Delta Waterfowl Foundation and other private conservation groups, the species continues to be sustainably hunted there. [2]
The pintail or northern pintail is a duck species with wide geographic distribution that breeds in the northern areas of Europe and across the Palearctic and North America. It is migratory and winters south of its breeding range to the equator. Unusually for a bird with such a large range, it has no geographical subspecies if the possibly conspecific duck Eaton's pintail is considered to be a separate species.
The northern shoveler, known simply in Britain as the shoveler, is a common and widespread duck. It breeds in northern areas of Europe and across the Palearctic and across most of North America, wintering in southern Europe, the Indian subcontinent, Southeast Asia, Central America, the Caribbean, and northern South America. It is a rare vagrant to Australia. In North America, it breeds along the southern edge of Hudson Bay and west of this body of water, and as far south as the Great Lakes west to Colorado, Nevada, and Oregon.
The Eurasian wigeon or European wigeon, also known as the widgeon or the wigeon, is one of three species of wigeon in the dabbling duck genus Mareca. It is common and widespread within its Palearctic range.
The American wigeon, also known as the baldpate, is a species of dabbling duck found in North America. Formerly assigned to Anas, this species is classified with the other wigeons in the dabbling duck genus Mareca. It is the New World counterpart of the Eurasian wigeon.
The mallard or wild duck 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. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae. 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 50–65 cm (20–26 in) long, of which the body makes up around two-thirds the length. The wingspan is 81–98 cm (32–39 in) and the bill is 4.4 to 6.1 cm long. It is often slightly heavier than most other dabbling ducks, weighing 0.7–1.6 kg (1.5–3.5 lb). Mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes.
The Eurasian teal, common teal, or Eurasian green-winged teal is a common and widespread duck that breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal is often called simply the teal due to being the only one of these small dabbling ducks in much of its range. The bird gives its name to the blue-green colour teal.
The Green-winged Teal or American Teal is a common and widespread duck that breeds in the northern areas of North America except on the Aleutian Islands. It was considered conspecific with the Eurasian teal for some time, but the two have since been split into separate species. The American Ornithological Society continues to debate this determination; however, nearly all other authorities consider it distinct based on behavioral, morphological, and molecular evidence. The scientific name is from Latin Anas, "duck" and carolinensis, "of Carolina".
The American black duck is a large dabbling duck in the family Anatidae. It was described by William Brewster in 1902. It is the heaviest species in the genus Anas, weighing 720–1,640 g (1.59–3.62 lb) on average and measuring 54–59 cm (21–23 in) in length with an 88–95 cm (35–37 in) wingspan. It somewhat resembles the female and eclipse male mallard in coloration, but has a darker plumage. The male and female are generally similar in appearance, but the male's bill is yellow while the female's is dull green with dark marks on the upper mandible. It is native to eastern North America. During the breeding season, it is usually found in coastal and freshwater wetlands from Saskatchewan to the Atlantic in Canada and the Great Lakes and the Adirondacks in the United States. It is a partially migratory species, mostly wintering in the east-central United States, especially in coastal areas.
The wood duck or Carolina duck is a partially migratory species of perching duck found in North America. The male is one of the most colorful North American waterfowls.
The mandarin duck is a perching duck species native to the East Palearctic. It is sexually dimorphic, with males showing a dramatic difference from the females. It is medium-sized, at 41–49 cm (16–19 in) long with a 65–75 cm (26–30 in) wingspan. It is closely related to the North American wood duck, the only other member of the genus Aix. 'Aix' is an Ancient Greek word which was used by Aristotle to refer to an unknown diving bird, and 'galericulata' is the Latin for a wig, derived from galerum, a cap or bonnet. Outside of its native range, the mandarin duck has a large introduced population in the British Isles and Western Europe, with additional smaller introductions in North America.
The harlequin duck is a small sea duck. It takes its name from Harlequin, a colourfully dressed character in Commedia dell'arte. The species name comes from the Latin word "histrio", meaning "actor". In North America it is also known as lords and ladies. Other names include painted duck, totem pole duck, rock duck, glacier duck, mountain duck, white-eyed diver, squeaker and blue streak.
The Muscovy duck is a duck native to the Americas, from the Rio Grande Valley of Texas and Mexico south to Argentina and Uruguay. Feral Muscovy ducks are found in New Zealand, Australia, and in Central and Eastern Europe. Small wild and feral breeding populations have also established themselves in the United States, particularly in Florida, Louisiana, Massachusetts, the Big Island of Hawaii, as well as in many other parts of North America, including southern Canada.
The comb duck or American comb duck, is an unusual duck, found in tropical wetlands in continental South America south to the Paraguay River region in eastern Paraguay, southeastern Brazil and extreme northeastern Argentina, and as a vagrant on Trinidad.
The falcated duck or falcated teal is a gadwall-sized dabbling duck from the east Palearctic.
The Pacific black duck is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the grey duck in New Zealand, where it is also known by its Maori name, pārera.
The black-bellied whistling duck, formerly called the black-bellied tree duck, is a whistling duck that before 2000 bred mainly in the southernmost United States, Mexico, and tropical Central to south-central South America. It can be found year-round in much of the United States. It has been recorded in every eastern state and adjacent Canadian province. Since it is one of only two whistling duck species native to North America, it is occasionally just known as the "whistling duck" or "Mexican squealer" in the southern USA.
The Brazilian teal or Brazilian duck is the only duck in the genus Amazonetta. It is widely distributed in eastern South America.
The red-billed teal or red-billed duck is a dabbling duck which is an abundant resident breeder in southern and eastern Africa typically south of 10° S. This duck is not migratory, but will fly great distances to find suitable waters. It is highly gregarious outside the breeding season and forms large flocks.
Coues's gadwall or the Washington Island gadwall, is an extinct dabbling duck which is only known by two immature specimens from the Pacific island of Teraina, Line Islands, Kiribati. They are in the National Museum of Natural History in Washington, D.C. The bird was named in honor of Elliott Coues.
The eastern spot-billed duck or Chinese spot-billed duck is a species of dabbling duck that breeds in East and Southeast Asia. This species was formerly considered a subspecies of the Indian spot-billed duck and both were referred to as the spot-billed duck. The name is derived from the yellow spot on the bill.
A. macula alarum rufa nigra alba.
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