I grew up seeing ducks. Maybe you did to. From my bird books, I identified all kinds of ducks and distinguished them by their plumage and behavior. I’ve seen ducks for sixty years, seen them beautifully fly, glide across a lake, dive and resurface, waddle cutely on land—always with the pervasive quack. But while my wife was shopping at Lake Arrowhead, I watched the ducks in crystal-clear water. I was amazed. I have never before witnessed the many ways in which ducks move their feet underwater. Their techniques are like that of a skilled canoeist. They narrow (or feather) their…