First some migration news: today at lunch, I had 2 White Eyed Vireos singing and flying about at Myrtle Grove in Charles County. Now the question: This morning I saw 4 birds flying overhead. They had pointy wings and long necks with dark heads. My first thought was Common Mergansers. When I checked the Yellow Book, I learned the peak of Co. Merg. migration is long past, and now is prime time to be seeing Common Loons. Then I read Todd Day's post about seeing some Loons yesterday morning and I really started to doubt my Common Merganser sighting. The question is, how can you tell if it's a Loon or a Merg? From below I couldn't see any of the droopyness of the head that loons have, in fact they looked like the head, neck and body was all on the same plane, but I was looking nearly straight up so that might be why. Also, is there a good way to tell a Common from a Red Breasted Loon in flight? I don't see a lot of any of these species in flight - does a correct id require lots of expirence with the various flight styles? Thanks, Bart Hutchinson