“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.
In one suggestion, it has been claimed that the Company of Merchant Adventurers to New Lands traded these ducks to Europe occasionally after 1550; this chartered company became eventually known as the “Muscovy Company” or “Muscovite Company” so the ducks might thus have come to be called “Muscovite ducks” or “Muscovy ducks” in keeping with the common practice of attaching the importer’s name to the products they sold. But while the Muscovite Company initiated vigorous trade with Russia, they hardly, if at all, traded produce from the Americas; thus, they are unlikely to have traded C. moschata to a significant extent.
The Ruddy Ducks are small, compact ducks with stout, scoop-shaped bills, and long, stiff tails they often hold cocked upward. They have slightly peaked heads and fairly short, thick necks. Male ruddy ducks have blackish caps that contrast with bright white cheeks. In summer, they have rich chestnut bodies with bright blue bills. In winter, they are dull gray-brown above and paler below with dull gray bills. Females and first-year males are brownish, somewhat like winter males but with a blurry stripe across the pale cheek patch. In flight, ruddy ducks show solidly dark tops of the wings.