White-billed Diver (Yellow-billed Loon) Gavia adamsii
This species is now known to undergo a regular spring migration through the remote islands offshore from northern Scotland. As a result it is not technically regarded as a vagrant to the UK any more, but for the vast majority of UK birders it is still a very rare bird indeed. The following individual was unbelievably approachable and delighted many hundreds of visitors during its stay.
adult White-billed Diver, Hayle (Cornwall, UK), 3rd March 2007