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.

Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group, since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water.