Birds I'm Watching: Common Merganser

Took a bike ride around Spring Lake today with my son. There were many ducks and geese on the water--and many, many people out as well. Of the ducks I was able to identify one that is a new sighting for me, the common merganser. One of these days, I'll get out to Spring Lake with a bird book, a pair of binoculars, and some time. Actually, chances are good that I've seen this bird before, but this is the first time I've seen it clearly and taken the time to identify it. Interesting that the males and females have such different plumage. I initially assumed these were two different species.