The wary American Black Duck of the Eastern US and Canada is prized by hunters, and there is no binocular birder either who is not happy to see them. Sadly, their numbers in the Northeast have been dropping while the population of their close relative the Mallard (with whom they commonly hydridize) have been rising.
Unlike most dabbling ducks, Blacks are happy breeding on either freshwater ponds and marshes or in salt marshes. Some studies in recent years indicate a significant reliance on beaver marshes for breeding habitat.
You can read about the American Black Duck here.
Photo from that site.