The Muscovy duck (Cairina moschata) 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.
It is a large duck, with the males about long, and weighing up to . Females are noticeably smaller, and only grow to , roughly half the males' size. The bird is predominantly black and white, with the back feathers being iridescent and glossy in males, while the females are more drab. The amount of white on the neck and head is variable, as well as the bill, which can be yellow, pink, black, or any mixture of these colors. It may have white patches or bars on the wings, which become more noticeable during flight. Both sexes have pink or red wattles around the bill, those of the male being larger and more brightly colored.
Although the Muscovy duck is a tropical bird, it adapts well to cooler climates, thriving in weather as cold as and able to survive even colder conditions. In general, Barbary duck is the term used for C. moschata in a culinary context.
The domestic subspecies, Cairina moschata domestica, is commonly known in Spanish as the pato criollo. They have been bred since pre-Columbian times by Native Americans and are heavier and less able to fly long distances than the wild subspecies. Their plumage color is also more variable. Other names for the domestic breed in Spanish are pato casero ("household duck") and pato mudo ("mute duck").
Description
All Muscovy ducks have long claws on their feet and a wide, flat tail. In the domestic drake (male), length is about and weight is , while the domestic hen (female) is much smaller, at in length and in weight. Large domesticated males often weigh up to , and large domesticated females up to .
The true wild Muscovy duck, from which all domestic Muscovies originated, is blackish, with large white wing patches. Length can range from , wingspan from and weight from . On the head, the wild male has a short crest on the nape. The bill is black with a speckling of pale pink. A blackish or dark red knob can be seen at the bill base, which is similar in colour to the bare skin of the face. The eyes are yellowish-brown. The legs and webbed feet are blackish. The wild female is similar in plumage, but much smaller, with a feathered face and lacking the prominent knob. The juvenile is duller overall, with little or no white on the upperwing.
Domesticated birds may look similar; most are dark brown or black mixed with white, particularly on the head. Other colors, such as lavender or all-white, are also seen. Both sexes have a nude black-and-red or all-red face; the drake also has pronounced caruncles at the base of the bill and a low erectile crest of feathers. C. moschata ducklings are mostly yellow with buff-brown markings on the tail and wings. For a while after hatching, juveniles lack the distinctive wattles associated with adult individuals, and resemble the offspring of various other ducks, such as mallards. Some domesticated ducklings have a dark head and blue eyes, others a light brown crown and dark markings on their nape. They are agile and speedy precocial birds.
The drake has a low breathy call, and the hen a quiet trilling coo.
The karyotype of the Muscovy duck is 2n=80, consisting of three pairs of macrochromosomes, 36 pairs of microchromosomes, and a pair of sex chromosomes. The two largest macrochromosome pairs are submetacentric, while all other chromosomes are acrocentric or probably telocentric for the smallest microchromosomes. The submetacentric chromosomes and the Z (female) chromosome show rather little constitutive heterochromatin (C bands), while the W chromosomes are at least two-thirds heterochromatin.
Male Muscovy ducks have helical penises that become erect to in s. Females have vaginas that coil in the opposite direction that appear to have evolved to limit forced copulation by males.
Etymology
Common name “Muscovy”
"Muscovy" is an old name for the region of Russia surrounding Moscow, but these ducks are neither native there nor were introduced there before they became known in Western Europe. It is not quite clear how the term came about; it very likely originated between 1550 and 1600, but did not become widespread until somewhat later.