Black Scoter Melanitta nigra
Until recently this North American was treated as a race of its Eurasian counterpart, Common Scoter Melanitta nigra. Black Scoter is extremely rare in the UK but the following individual wintered off north Wales for several years. It was usually very distant indeed and required a high magnification telescope to see, let alone photograph. The following photo was taken through a telescope with a 50x eyepiece and cropped extremely heavily, but you can still make out the much more extensive yellow on the bill, and the more bulbous bill structure, compared to the accompanying Common Scoters.
male Black Scoter (second from left) with Common Scoters, Llanfairfechan (Conwy, UK), 10th November 2007