Anatra mandarina

Identificazione

The mandarin duck is among the more diminutive types of waterfowl, with a shorter height and smaller overall body size than the dabbling ducks, and is slightly smaller than its American wood duck relatives. The adult male has a petite, red bill, large white crescent above the eye and reddish face and "whiskers". The male's breast is purple with two vertical white bars, the flanks ruddy, and he has two orange feathers at the back (large feathers that stick up similar to boat sails). The female is similar to the female wood duck, with a grayish-lavender tone to her plumage, and a white eye-ring and stripe running back from the eye. The female is paler on the underside, has a small white flank stripe, and a pale tip to its bill.<p>Both the males and females have crests, but the purple crest is more pronounced on the male.<p>Like many other species of ducks, the male undergoes a moult after the mating season into eclipse plumage. When in eclipse plumage, the male looks similar to the female but can be distinguished by its bright yellow-orange or red beak, lack of any crest, and a less-pronounced eye-stripe.<p>Mandarin ducklings are almost identical in appearance to wood ducklings, and 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.[citation needed]<p>Various mutations of the mandarin duck are found in captivity. The most common is the white mandarin duck. Although the origin of this mutation is unknown, the constant pairing of related birds and selective breeding is presumed to have led to recessive gene combinations, leading in turn to genetic conditions including leucism.[citation needed]

Tassonomia

Nome scientifico

Aix galericulata

Autorità

(Linnaeus, 1758)

Ordine

Anseriformi

Famiglia

Anatidae

Genere

Aix

Areale e habitat

The species was once widespread in East 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. The Asian populations are migratory, overwintering in lowland eastern China and southern Japan.<p>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. Now, about 7,000 are in Britain with other populations on the European continent, the largest of which is in the region of Berlin. Isolated populations exist in the United States. The town of Black Mountain, North Carolina, has a limited population, and a free-flying feral population of several hundred mandarins exist in Sonoma County, California.[citation needed] This population is the result of several ducks escaping from captivity, then reproducing in the wild. In 2018, a single bird, dubbed Mandarin Patinkin, was seen in New York City's Central Park.<p>The habitats it prefers in its breeding range are the dense, shrubby forested edges of rivers and lakes. It mostly occurs in low-lying areas, but it may breed in valleys at altitudes of up to 1,500 m (4,900 ft). In winter, it additionally occurs in marshes, flooded fields, and open rivers. While it prefers fresh water, it may also be seen wintering in coastal lagoons and estuaries. In its introduced European range, it lives in more open habitat than in its native range, around the edges of lakes, water meadows, and cultivated areas with woods nearby.

Areale riproduttivo

PAL : se Siberia, Korean Pen., Japan and e China

Areale non riproduttivo

se China

Migrazione

Complete migrants

Comportamento

Compared to other ducks, mandarins are shy birds, preferring to seek cover under trees such as overhanging willows, and form smaller flocks, but may become bolder as a result of becoming tame from frequent interaction with humans.<p>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 during the spring. A single clutch of nine to twelve eggs is laid in April or May. Although the male may defend the brooding female and his eggs 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.<p>Mandarins feed by dabbling or walking on land. They mainly eat plants and seeds, especially beech mast. 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.<p>Like many other bird species, Mandarin ducks display conspecific brood parasitism. Typically, Mandarin ducks lay their eggs in nests of their own relatives or other bird species. In the Zuojia Nature Reserve in Northeast China, 46.1% of Mandarin ducks were found to practice conspecific brood parasitism. Female ducks lay their eggs in different nests for a wide variety of reasons. For example, when there are nest limitations or there are little resources available, female ducks are more likely to practice conspecific brood parasitism. When females practice this behavior, they can benefit from a decrease in the costs from parental care and incubation. Additionally, female parasitic ducks can reduce their risks from predation. <p>While there was speculation that larger clutch sizes can lead to an increase in resource competition, research has found that the number of parasite eggs had no negative influence on the success of eggs from the host. Over generations, conspecific brood parasitism can increase the net number of offsprings found within each generation. Overall, other duck species that have utilized this behavior to lay their eggs were able to increase their reproductive success by more than double.

Conservazione

Tendenza della popolazione

declining