Jim Stasz is exactly right. Mark Hoffman's photos are of the bird pointed out to him by the original observers. They match, feather for feather, pix taken on other days. The chances that different birds are involved is minuscule. Yes, there were other birds approaching the pattern seen on the "Common" Gull, but all of them had characters associated with the tail that distinguished them. I saw at least three that could easily have been mistaken by observers uncertain of what were the diagnostic characters or who were unable to get a close enough look, but they were not the same and they were not among the ones we looked at photos of. Of course, to restate something from an earlier post: If there were three or four birds with this identical tail pattern then one is condemned to argue that Common Gulls occur at Conowingo in flocks or that the tail pattern is not diagnostic. Rick "A writer is somebody for whom writing is more difficult than it is for other people." Thomas Mann Rick Blom rblom@blazie.com Bel Air, Maryland