For three generations, Ducks, Geese, and Swans of North America has been the Bible of American wildfowl guides. From its humble beginnings as Frances Kortright’s single volume, through its expansion and new text under Frank Belrose, to this incredible two-volume version by the late Guy Baldassarre, it has been a necessity for birders, hunters, and scientists who study these birds.
With no disrespect to Baldassarre’s predecessors, this is the best version. He had access to more information than Kortright or Bellrose. Add an amazing number of stunning photographs to the classic illustrations, and you have a book without equal.
One species can serve as an example of how much has been learned recently. Snow Goose and Blue Goose were considered separate species until 1983! We learn from Baldassarre that they are two morphs of one subspecies, the Lesser Snow Goose, but the populations were largely separate before their recent expansion. And the Siberian population of Lesser Snow Goose, which researchers thought had dropped from several hundred thousand to extinction, has a relic population of about 100. The human-driven expansion of the Lesser Snow Goose is not a “mere” 3.8 million but 18.7 million and growing; a little history, a lot of environmental implications.
If you are interested in waterfowl, I highly recommend this book.