Muscovy duck

Name and taxonomy

Carl Linnaeus named the bird Anas moschata in 1758, in the tenth edition of Systema Naturae. His account ran to a few words about the naked, warty face. Later authors moved the species to the genus Cairina, so the name is now Cairina moschata. The genus name comes from Cairo, and the species name means musky. The scientific name therefore says the musky duck of Cairo, and the bird lives in neither place.

Muscovy is an old English name for the country around Moscow. The duck is not Russian, and no trader carried it there first. The early naturalists could not agree on where the bird came from. Many European languages call it the musk duck, such as the German Moschusente. The species is monotypic, and nobody recognises a subspecies.

Evolution and relatives

The Muscovy duck belongs to the Anatidae, the family of ducks, geese and swans. Older books placed it with the perching ducks, a grouping that later work broke up. Authors then moved it into the dabbling duck subfamily Anatinae. Gene sequences from cytochrome b and NADH dehydrogenase subunit 2 point elsewhere again. They place the duck near Aix, the genus of the wood ducks, in the subfamily Tadorninae.

The white-winged duck once shared the genus and now stands alone as Asarcornis scutulata. That leaves the Muscovy duck as the only living member of Cairina. A chromosome-level genome appeared in 2026, about 1.27 gigabases across 39 chromosomes. The study counted 16,901 genes that code for protein. Gene families tied to immunity had grown, which may explain the bird's hardiness.

Appearance

This is a heavy duck with a long body, a wide flat tail and long claws. Males measure 76 to 84 centimetres, and females measure 71 to 76 cm. A drake weighs about 3 to 4 kilograms, and a female about 1.25 kg. The wingspan runs from 137 to 152 cm and averages about 145 cm. Animal Diversity Web gives a mass range of 2.7 to 6.8 kg for farm and wild birds together.

Wild birds are mostly black, with a large white patch on each wing. The drake's back and wing feathers throw off a green and purple gloss. Bare red skin covers the face, and a dark knob sits above the bill. The bill is black with pale pink speckles, and the eyes are yellowish brown. The male carries a short crest on the nape and can raise it at will. Farm birds vary far more, and many are white, pied, buff, chocolate, lilac or blue.

Habitat and range

The wild bird lives in swamp forest and along slow rivers, lakes and streams. It feeds in the grassland and on the crop fields that sit beside the water. At night it roosts in trees, which few ducks do. The native range runs from Texas and Mexico to Argentina and Uruguay. The species does not migrate, and a bird may spend its life in one valley.

Feral birds now breed on town lakes, farm ponds and park water far outside that range. Populations live in Florida, Louisiana, Massachusetts and southern Canada. Others live in New Zealand, Australia and parts of central and eastern Europe. Small British flocks sit at Ely, Calstock, Lincoln and Buxton. GBIF holds occurrence records from 190 countries, and most of those birds are farmed or feral. The tropical bird copes with frost and does well at -12 degrees Celsius.

Diet and feeding

The Muscovy duck is an omnivore, and it takes much more than pond weed. It eats the roots, stems, leaves and seeds of water plants and grasses. It grazes on land and dabbles in the shallows for the rest. Animal food includes small fish, amphibians, reptiles and crustaceans. It also takes spiders, insects, millipedes, termites and worms.

Crops make up part of the diet where a field meets the water. Ducklings start on grain, grass, insects and almost any small moving animal. Their mother shows them what to eat within days of hatching. Adults will peck at ducklings that crowd the same food. Like other dabbling ducks, it feeds by day and rests at night.

Behaviour and social life

Muscovy ducks live in loose flocks with a clear rank order. Males hold territories and drive other males off them. A drake lifts his crest and wags his tail to state his rank. Fights break out over food, over ground and over females. Females quarrel with each other less often than males do.

Males that lose form small bachelor groups inside another bird's ground. The species is active by day and stays in one place all year. Birds often sleep on the water, which gives them a head start from a fox. Wild birds fly well and land in trees, gripping the bark with their claws. Farm birds are heavier and cover little ground in the air.

Communication and senses

This duck does not quack the way a mallard does. The drake makes a low breathy sound, and the hen a quiet trilling coo. Both sexes hiss at a threat, and the sound carries a plain warning. Soft quacking keeps a hen and her ducklings in touch. The calls are quiet, so they probably carry only a short way across the water.

Much of the talk is silent, and the birds signal with the body instead. A raised crest states dominance to a rival male. The crest also draws females, and they pick large males with large crests. Birds raise and lower their heads at one another when they meet. Like other ducks, it has sharp colour vision and a wide field of view.

Reproduction and life cycle

Pairs do not stay together, and the mating system looks like a lek. A few males father most of the ducklings, and many males never breed. Breeding runs from early August to early May in the native range. A hen can raise two or three broods within one year.

She nests in a tree hollow, often 3 to 18 metres above the ground. The nest is a cup of twigs, stems and mud. She lays 8 to 15 white eggs, and a typical clutch holds 8 to 10. Each egg is about 6.2 to 7.1 centimetres long. She sits on the eggs for 30 to 31 days, and some accounts stretch that to 35. She leaves the nest once a day, for 20 minutes to an hour and a half.

Hatching can take a whole day once the first shell cracks. Ducklings cannot hold their own heat, so they press against their mother at night. They follow her for about 10 to 12 weeks and then feed themselves. The drake often walks with the brood and guards it for several weeks. Females can breed at about 28 weeks of age and males at about 29 weeks. Wild birds live 7 to 8 years, and 9 years is a high figure in captivity.

Predators and threats

Ducklings are the easy target, and many die in their first weeks. Animal Diversity Web names dogs and red foxes as the known predators. Birds sleep on open water so they can swim clear of a night attack. When something disturbs them they alarm call, freeze or run. A hen defends her brood, and she may strike at a dog that comes too near.

Hunting is the main pressure on wild birds in the east of the range. The duck has become uncommon there for that reason. Avian influenza is the other killer, and the H5N1 subtype wipes out whole flocks. Clearing of swamp forest probably removes the tree holes a hen needs. Breeding with escaped farm birds may also weaken the wild stock.

Population and conservation

The IUCN lists the Muscovy duck as Least Concern. That listing rests on the very wide range rather than on a head count. Wild numbers appear to be falling even so. Farm and feral birds are common, and they probably hide that loss from most people.

iNaturalist records regional listings that are far stricter than the global one. Uruguay lists the duck as Endangered. Mexico places it on the official list of species at risk of extinction. French Guiana lists it as Near Threatened, and Argentina puts it in a threatened class. Nest boxes in Mexico have helped local numbers.

Relationship with humans

Peoples of the Americas had domesticated the duck by the time Columbus reached the Bahamas. Sailors carried a few birds home on the Santa Maria in the early 16th century. The bird now stands in farmyards across the world. It gives meat, eggs and down, and the dressed carcass sells as Barbary duck. Spanish speakers call the farm bird pato criollo.

Farmers cross a Muscovy drake with a Pekin hen to make the mulard. Mulards cannot breed, and France raised about 35 million of them a year by 2007. Ducks turned into a cow pen cut fly numbers by 80 to 90 percent. Growers also use them against snails, slugs, locusts and grasshoppers.

In the United States the bird counts as non-native outside three counties of southern Texas. Federal rules there allow the removal of feral birds, their eggs and their nests. Feral flocks foul paths and gardens, and some towns treat them as pests. A cornered duck will bite, and its claws can scratch a hand.

In culture and myth

The English name has puzzled writers for four hundred years. One story credits the Muscovy Company, which traded with Russia after 1550. That company dealt in Russian goods and not in American ones, so the story is weak. Another reading treats Muscovy as a word for anywhere far away. The turkey and the guineafowl carry the same kind of misleading name.

A third idea points to the Muisca people of what is now Colombia. They kept the duck, and their name may have shifted into Muscovy in European mouths. The Miskito people of Nicaragua and Honduras also relied on the bird at home. Ulisse Aldrovandi called it the Cairo duck, the Indian duck and the Libyan duck. Francis Willughby decided that all three names belonged to one bird. John Ray then tied the name to the strong musky smell instead.