Anas rubripes

Appears to constitute a superspecies with A. platyrhynchos and A fulvigula (AOU 1998). Commonly interbreeds with and sometimes considered conspecific with A. platyrhynchos and/or other species (AOU 1983). Some authors suggest that it might be taxonomically appropriate to recognize the black duck as a dark morph (not subspecies) of the mallard, based on genetic and behavioral similarity and frequent hybridization (Ankney et al. 1986) in this species (AOU 1983). Mitochondrial DNA data indicate an extremely close evolutionary relationship between mallards and black ducks, and, in conjunction with geographic distribnutions, suggest that the black duck is a recent evolutionary derivative of a more broadly distributed mallard-black duck ancestor (Avise et al. 1991). See Livezey (1991) for a phylogenetic analysis and classification (supergenera, subgenera, infragenera, etc.) of dabbling ducks based on comparative morphology.

High population numbers, but declining due to overhunting and increasing hybridization.

BREEDING: northern Saskatchewan to Labrador and Newfoundland, south to northern South Dakota, southern Wisconsin, central Indiana, central West Virginia, and North Carolina on Atlantic coast. NON-BREEDING: southeastern Minnesota to southern Ontario and Nova Scotia, south to Texas, Gulf Coast, and Florida. The highest winter densities occur along the Maumee River in Ohio, along the Kankakee River in Illinois, along the Mississippi River bordering Tennessee and extending along the Ohio River to southwestern Indiana, in southwestern Tennessee and northern Alabama, and along the U.S. Atlantic coast from eastern North Carolina to Maine (Root 1988).

This is an estimate. With a breeding range that encompasses the northeastern U.S. states and much of eastern Canada up to Hudson Bay (Longcore, et. al. 2000) and an estimated 900,000 individuals (National Audubon Society, 2014) , there are undoubtedly more than 81 element occurrences.

Recent decline attributed to habitat change and loss, hybridization and/or competition with Mallard (Ankney et al. 1987; see also Conroy et al. 1989, Ankney et al. 1989, and Merendino and Ankney 1994), and possibly over-hunting (Krementz et al. 1988), and the effects of acid precipitation and aerial spraying for spruce budworm (Ehrlich et al. 1992). Rusch et al. (1990) reviewed status and concluded that hunting and loss of breeding habitat apparently are not major factors in the decline; loss of winter habitat in some areas was noted. Chesapeake Bay breeding populations have declined since the 1950s; the decline is not related to changes in laying date, clutch size, or nest success (Krementz et al. 1991). There is some evidence that this species is much more intolerant of human disturbances than other duck species, including abandonment of nests due to flushing (Longcore, et.a l., 2000).