Surprising Genetic Sameness in Three Mallard-like Ducks, and One Distinctive Variety

Photographs: Mexican Duck, American Black Duck, and Mallard © Lauren Lavretsky; Mottled Duck (WGC) © Greg R. Homel /; Mottled Duck (FL) © Ron Bielefeld

(July 23, 2014, The Auk: Ornithological Advances)—Mallards are iconic and cosmopolitan waterfowl, the ancestors of domesticated stocks, and infamous for their ease of invasion into new geographic regions and hybridization with other mallard-like ducks. But what are the evolutionary relationships of mallards and their relatives across and within species? New research by Lavretsky et al. examines whether genetic underpinnings parallel the morphological distinctiveness of 4 mallard-like ducks in North America, including the Mallard, the American Black Duck, the Mexican Duck, and the Mottled Duck. Shockingly, the Mallard, American Black Duck, and Mexican Duck were genetically indistinguishable based on a survey of 18 genetic markers. In contrast, distant populations of the Mottled Ducks had diagnostic genetic differences that were comparable to the differences observed between mottled ducks and the other three species. These data are suggestive of recent and rapid speciation in this complex, and, critically, are inconsistent with current taxonomy. Clearly, more work awaits to understand the genetics of duck taxonomy even in our own backyards. Read the open access article at