Showing posts with label Genus Aix. Show all posts
Showing posts with label Genus Aix. Show all posts

Sunday, May 13, 2012

>Aix sponsa (Wood Duck)

Wood Duck


Wood Duck
Male in St James's Park, London, England
Female at Crystal Springs Rhododendron Garden, Oregon, U.S.
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Anseriformes
Family:Anatidae
Genus:Aix
Species:A. sponsa
Binomial name
Aix sponsa
(Linnaeus, 1758)
Breeding (light green), wintering (blue) and year-round (dark green) ranges of A. sponsa.
The Wood Duck or Carolina Duck (Aix sponsa) is a species of duck found in North America. It is one of the most colourful of North American waterfowl.

Description

The Wood Duck is a medium-sized perching duck. A typical adult is from 47 to 54 cm (19 to 21 in) in length with a wingspan of between 66 to 73 cm (26 to 29 in). This is about three-quarters of the length of an adult Mallard. It shares its genus with the Asian Mandarin Duck(Aix galericulata).
The adult male has distinctive multicoloured iridescent plumage and red eyes,with a distinctive white flare down the neck. The female, less colourful, has a white eye-ring and a whitish throat. Both adults have crested heads.
The male's call is a rising whistle, "jeeeeee"; the females utter a drawn-out, rising squeal, "oo-eek," when flushed, and a sharp "cr-r-ek, cr-e-ek" for an alarm call.

Behaviour

Their breeding habitat is wooded swamps, shallow lakes, marshes or ponds, and creeks in eastern North America, the west coast of the United States and western Mexico. They usually nest in cavities in trees close to water, although they will take advantage of nesting boxes in wetland locations if available. Females line their nests with feathers and other soft materials, and the elevation provides some protection from predators. Unlike most other ducks, the Wood Duck has sharp claws for perching in trees and can, in southern regions, produce two broods in a single season—the only North American duck that can do so.
Females typically lay between 7 and 15 white-tan eggs that incubate for an average of 30 days. However, if nesting boxes are placed too close together, females may lay eggs in the nests of their neighbours, which may lead to nests which may contain as many as 30 eggs and unsuccessful incubation, a behaviour known as "nest dumping".
After hatching, the ducklings jump down from the nest tree and make their way to water. The mother calls them to her, but does not help them in any way. The ducklings may jump from heights of up to 88 metres (290 ft) without injury. They prefer nesting over water so the young have a soft landing, but will nest up to 140 m (150 yd) away from the shoreline. The day after they hatch, the young climb to the nest entrance and jump to the ground. The ducklings can swim and find their own food by this time.
These birds feed by dabbling or walking on land. They mainly eat berries, acorns, and seeds, but also insects, making them omnivores.

Distribution

The birds are year-round residents in parts of its southern range, but the northern populations migrate south for the winter. They overwinter in the southern United States near the Atlantic coast. 75% of the Wood Ducks in the Pacific Flyway are non-migratory.They are also popular, due to their attractive plumage, in waterfowl collections and as such are frequently recorded in Great Britain as escapes—populations have become temporarily established in Surrey in the past but are not considered to be self-sustaining in the fashion of the closely related Mandarin Duck. Given its native distribution the species is also a potential natural vagrant to Western Europe and there have been records in areas such as Cornwall and the Isles of Scilly which some observers consider may relate to wild birds; however, given the Wood Duck's popularity in captivity it would be extremely difficult to prove their provenance one way or another. There is a small feral population in Dublin.

Conservation

The population of the Wood Duck was in serious decline in the late 19th century as a result of severe habitat loss and market hunting both for meat and plumage for the ladies' hat market in Europe. By the beginning of the 20th century Wood Ducks had virtually disappeared from much of their former range. In response to the Migratory Bird Treaty established in 1916 and enactment of the Federal Migratory Bird Treaty Act of 1918, wood duck populations began to slowly recover. By ending unregulated hunting and taking measures to protect remaining habitat, wood duck populations began to rebound in the 1920s. The development of the artificial nesting box in the 1930s gave an additional boost to Wood Duck production.
Landowners as well as park and refuge managers can encourage Wood Ducks by building Wood Duck nest boxes near lakes, ponds, and streams. Fulda, Minnesota has adopted the Wood Duck as an unofficial mascot, and a large number of nest boxes can be found in the area.
Expanding North American Beaver populations throughout the Wood Duck's range have also helped the population rebound as beavers create an ideal forested wetland habitat for Wood Ducks.
The population of the Wood Duck has increased a great deal in the last several years. The increase has been due to the work of many people constructing Wood Duck boxes and conserving vital habitat for the Wood Ducks to breed. During the open waterfowl season, U.S. hunters have only been allowed to take two Wood Ducks per day in the Atlantic and Mississippi Flyways. However, for the 2008–2009 season, the limit was raised to three. The Wood Duck limit remains at two in the Central Flyway and at seven in the Pacific Flyway. It is the second most commonly hunted duck in North America, after the mallard.

Gallery

>Aix galericulata (Mandarin Duck)

Mandarin Duck

Mandarin Duck
A pair in Switzerland
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Anseriformes
Family:Anatidae
Genus:Aix
Species:A. galericulata
Binomial name
Aix galericulata
(Linnaeus, 1758)
The Mandarin Duck (Aix galericulata), or just Mandarin, is a medium-sized perching duck, closely related to the North American Wood Duck. It is 41–49 cm long with a 65–75 cm wingspan.

Description

The adult male is a striking and unmistakable bird. It has a red bill, large white crescent above the eye and reddish face and "whiskers". The breast is purple with two vertical white bars, and the flanks ruddy, with two orange "sails" at the back. The female is similar to female Wood Duck, with a white eye-ring and stripe running back from the eye, but is paler below, has a small white flank stripe, and a pale tip to its bill.The Mandarin ducklings are almost identical in look to Wood ducklings, and appear very similar to Mallard ducklings. The ducklings can be distinguished from Mallard ducklings because the eye-stripe of Mandarin ducklings (and Wood ducklings) stops at the eye, while in Mallard ducklings it reaches all the way to the bill.

Mutations


A mandarin duck swimming in Shepreth Wildlife Park
There are various mutations of the Mandarin Duck found in captivity. The most common is the white Mandarin Duck. Although the origin of this mutation is unknown, it is presumed that the constant pairing of related birds and selective breeding led to recessive gene combinations leading to genetic conditions including albinism.

Distribution and habitat


Male flying in Dublin, Ireland
The species was once widespread in eastern Asia, but large-scale exports and the destruction of its forest habitat have reduced populations in eastern Russia and in China to below 1,000 pairs in each country; Japan, however, is thought to still hold some 5,000 pairs.
Specimens frequently escape from collections, and in the 20th century a large feral population was established in Great Britain; more recently small numbers have bred in Ireland, concentrated in the parks of Dublin. There are now about 7000 in Britain, and other populations on the European continent, the largest in the region of Berlin.
Black Mountain, North Carolina also has a limited population.There is also a free-flying feral population of several hundred mandarins in Sonoma County, California. This population is the result of several mandarin ducks escaping from captivity, then going on to reproduce in the wild.

Behaviour and ecology

Breeding


A female parent with ducklings in Richmond Park, London, England
In the wild, Mandarin Ducks breed in densely wooded areas near shallow lakes, marshes or ponds. They nest in cavities in trees close to water and during the spring, the females lay their eggs in the tree's cavity after mating. Although the male may defend the female during incubation, he himself does not incubate the eggs and leaves before they hatch. Shortly after the ducklings hatch, their mother flies to the ground and coaxes the ducklings to leap from the nest. After all of the ducklings are out of the tree, they will follow their mother to a nearby body of water. The Asian populations are migratory, overwintering in lowland eastern China and southern Japan.

Food and feeding

Mandarins feed by dabbling or walking on land. They mainly eat plants and seeds, especially beechmast. The species will also add snails, insects and small fish to its diet. The diet of Mandarin Ducks changes seasonally, in the fall and winter, they mostly eat acorns and grains. In the spring they mostly eat insects, snails, fish and aquatic plants. In the summer, they eat dew worms, small fish, frogs, mollusks, and small snakes.They feed mainly near dawn or dusk, perching in trees or on the ground during the day.

Threats

Predation of the Mandarin Duck varies due to its geological ranges. Mink, raccoon dogs, otters, polecats, eurasian eagle owls, and grass snakes are all predators of the Mandarin Duck. The greatest threat to the Mandarin Duck is habitat loss due to loggers. Hunters are also a threat to the Mandarin Duck, because oftentimes, they are unable to recognize the Mandarin in flight and as a result, many are shot on accident. Mandarin ducks are not hunted for food, however they are still poached because their extreme beauty is prized.

In Chinese culture

Mandarin Ducks, which are referred to by the Chinese as Yuan-yang (simplified Chinese: 鸳鸯; traditional Chinese: 鴛鴦; pinyin: yuān yāng), where yuan(鴛) and yang(鴦) respectively stand for male and female Mandarin Ducks.
In traditional Chinese culture, Mandarin Ducks represent a life-time couple, unlike many other species of ducks. Hence they are frequently featured in Chinese art and are regarded as a symbol of conjugal affection and fidelity.
A Chinese proverb for loving couples uses the Mandarin Duck as a metaphor: "Two mandarin ducks playing in water" (simplified Chinese: 鸳鸯戏水; traditional Chinese: 鴛鴦戲水; pinyin: yuān yāng xì shuǐ). The Mandarin Duck symbol is also used in Chinese weddings, because in traditional Chinese lore they symbolize wedded bliss and fidelity.
Because the male and female plumages of the Mandarin Duck are so unalike, yuan-yang is frequently used colloquially in Cantonese to mean an "odd couple" or "unlikely pair" – a mixture of two different types of same category. For example, yuanyang (drink) and yuan-yang fried rice.

Gallery

>>Genus Aix

Aix (genus)


Aix
Pair of Wood Ducks (Aix sponsa)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Anseriformes
Family:Anatidae
Genus:Aix
F. Boie, 1828
Species
  • A. galericulata
  • A. sponsa
Aix is a genus that contains two species of ducks: the Wood Duck (Aix sponsa), and the Mandarin Duck (Aix galericulata).
The genus belongs to the family Anatidae in the waterfowl order Anseriformes. They were formerly placed in the "perching ducks", a paraphyletic group somewhat intermediate between shelducks and dabbling ducks, and it is not quite clear whether they should be placed in the Anatinae (dabbling duck) or Tadorninae (shelduck) subfamily.
The two species are generally considered to be very attractive, particularly the multi-coloured drakes. Wood Ducks are a North American species,occurring mainly in the eastern half of the United States, and from southern Canada to northern Mexico. Mandarin Ducks are an Asian species mainly in Japan and China, but there is an important feral population in the United Kingdom. Both species migrate from the northern parts of their respective ranges to winter in the south of the range. They inhabit quiet wooded streams and ponds.
The genus shows marked sexual dimorphism (differences between the sexes), with the females being smaller and less colorful.
The Wood Duck has a mass of 500–700 grams (18–25 oz). It is 41–49 centimeters (16–19 in) in length, and has a wingspan of 73–75 cm (29–30 in). Males have red eyes and iridescent plumage. Both sexes have crested heads.
The Mandarin Duck is 41–49 cm (16–19 in) long with a 65–75 cm (26–30 in) wingspan. It has an even more flamboyant plumage than the Wood Duck. The female Mandarins are less brightly colored than the males.

Mandarin Duck (Aix galericulata)
Wood Ducks will consume small crustaceans,insects, and plant matter. Mandarin Ducks are mainly vegetarian.
Wood Ducks are reproductively capable around the age of one year. They are monogamous for the season. Mating occurs between February and April, depending on latitude. The clutch size is between 6 and 15, and the incubation period is about 30 days. The young are precocial. They venture from the cavity nest at one day old and are cared for by the mother for about 60 days. The young have a very high mortality rate. Wood Ducks normally live 3 to 4 years.
Mandarin Ducks are also monogamous. The courtship ritual, like the plumage, is rather showy. The female lays between 9 and 12 eggs in a cavity nest, then incubates them for about 30 days. Parental care by the mother is a little shorter in this species, lasting about 40 days.
Both species are threatened by loss of habitat. As human development continues to expand, the woodland areas preferred by these ducks continues to shrink. The Mandarin Ducks may number less than 20,000.