American Black Ducks, a male and two females, in the marsh creek next to Petey’s restaurant in Rye, N.H.

I just learned to tell these ducks apart from the ubiquitous mallard and yesterday I counted 13 of them in this location (“Massacre Marsh at Parson’s Creek”) along with 23 Canada Geese, 17 Mallard and 1 Herring Gull. I entered my observation on my eBird life list, begun January 2014, and the black duck is #100 on the list.

The American Black Duck hides in plain sight in shallow wetlands of eastern North America. They often flock with the ubiquitous Mallard, where they look quite similar to female Mallards. But take a second look through a group of brown ducks to notice the dark chocolate-brown flanks, pale grayish face, and olive-yellow bill of an American Black Duck.

And…

Large, bulky ducks, nearly identical in shape to Mallard. Mostly dark brown overall with pale head/neck. Males show bright yellow/green bill, duller olive on female.