Distribution

Muscovy Duck commonly is kept in captivity, and feral populations and free ranging domestic type Muscovies now occur well outside its original range, which extends from extreme southern Texas and northern Mexico south to northern Argentina. In Mexico, Muscovy occurs on both slopes:, north along the Gulf coast to northern Tamaulipas and central Nuevo Leon (Cruz-Nieto 1991, Whitley 1973, Rojas 1954). It is rare in the Yucatan Peninsula, but common in Belize southward through the remained of Central America (Bolen 1983). On the Pacific slope its distribution extends from southern Sinaloa in Mexico south through Panama (Wetmore 1965). Muscovy Duck is very local on the Pacific slope of South America, where it is reported from western Colombia in northern Chocó and Nariño (Hilty and Brown 1986), and in southwestern Ecuador in Guayas (Ridgely and Greenfield 2001a). Its distribution is more continuous in the lowlands north and south of the Andes, where it is widespread (Gomez-Dallmeier and Crigan 1989, Haverschmidt 1968), south to northern Argentina.

Perhaps the largest established feral population of Muscovy Duck is in Florida, southeastern United States (Robertson and Woolfenden 1992, Pranty et al. 2006).

Muscovy Duck is considered resident across most of its range, but at least locally, as in Venezuela, it has "marked local and seasonal migratory movements" (Hilty 2003).

Muscovy Duck strictly occurs in the lowlands, with upper elevational limits of 1200 m in Mexico (Howell and Webb 1995), mostly below 500 m in Colombia (but wandering to as high as 2600 m; Hilty and Brown 1986), to 300 m in Venezuela (Hilty 2003) and in Ecuador (Ridgely and Greenfield 2001a), and to 600 m in Bolivia (Hennessey et al. 2003).

Widely distributed as a feral and domesticated species.

It inhabits tropical forest, wetlands, prefers lowlands and occasionally in coastal lagoons, between sea level to 1200 m asl.

Muscovy Duck expanded its range from Mexico north into the lower Rio Grande Valley of Texas, United States, only as recently as 1984, with the first Texas nesting reported in 1994 (Brush and Eitniear 2002, Lockwood and Freeman 2014).

Otherwise the historical trend is one of population declines and range contractions, presumably due primarily to hunting pressure. In Colombia, for example, it formerly occurred in the Cauca and Magdalena Valleys (Meyer de Schauensee 1948) but no longer is present in these regions (Hilty and Brown 1986). It may have occurred north in western Ecuador to southern Pichincha and south to El Oro, but now occurs only in Guayas; and in eastern Ecuador it has been extirpated from sites where it occurred as recently as the 1970s (Ridgely and Greenfield 2001a).

Wetmore (1956) excatated several bones from Muscovy ducks in Panama. Dating showed them to be from the upper Pleistocene. Bones of this species also during that time were found in Brazil indicating it had a wide range during the Pleistocene. The earliest fossils that can be identified as anseriform were those of Anatalavis rex; two bones recovered from the Hornerstown Formation of New Jersey may date back to the Late Cretaceous or early Paleocene (80–50 million years ago) (Stahl 2005). Archaeological evidence also exist for the species presence in Ecuador (Hesse 1989).