Along with seeing the native ducks in North America, there are also the possibility of seeing the non-native ducks from Eurasia, Mexico, Central and South America and ducks from the Caribbean Islands. On this site, you will be able to view all these ducks. Also, included there are ducksare possible of the sighting of escaped birds from wildlife centres and private breeders. Not included among these waterfowl are the eiders, loons, grebes and mergansers.
Among these different types, the birds can be grouped again into puddle, aka "dabbling" and diving ducks. The dabblers mostly feed in smaller bodies of shallow water or along shorelines, where they are able to tip their bodies forward to reach their food on the bottom. There are divers who feed in deeper water where they dive and pursue their quarry. Some of these birds, the Harlequin Duck, for example, actually dives to the bottom of fast-flowing waters and feeds on life forms attached to rocks.
Avibase - the world bird database This site provides the user with a complete list of bird species, broken down per country, or in the example of the US or Canada, per state and province. Here, bird species names are available in other languages, a great asset to be used as a translation of foreign bird names.
ABA - American Birding Association This site represents an organization that maintains official records of all birds species that have been proven to have been seen inside the perimeters of the North American Continent and the surrounding bodies of water. Regular revised versions are posted to keep the bird list current at all times. This is the list used by all serious birders over their lifetime. You may be aware of the movie called the "Big Year". It was with this list that all the competing birders used in an attempt to set a new record as to how many bird species that could be seen by an individual birder in one calendar year.
I hope you will take advantage of these suggested websites. I have used each of them, in one way or another, throughout the years in my quest to better identify and understand our fine feathered friends.