Other Seabirds
I include Gannet, Albatross, Cormorant and Shag within this group. There are three species of Gannet Worldwide and only one occurs in Britain. Although they do not breed anywhere near Cornwall, they are seen in large numbers most months of the year. In 1985 a Cape Gannet was seen off the coast of Spain; this southern hemisphere bird is similar to our Northern Gannet and may well have gone un-noticed off the British coast.
Although very rare, Black-browed Albatross has occurred in Gannet breeding colonies off Britain. There are also occasional sightings off the Cornish coast and one was very probably seen in the late 1990's on the annual RMV Scillonian pelagic trip. This bird was seen by a few very experienced birders from the rear of the boat.
There are 39 species of Cormorant and Shag, but Only Great Cormorant and European Shag, occur around the coast of Britain. Greats can also be found on reservoirs.
As for other seabirds, Red-billed Tropicbird and Magnificent Frigatebird are extremely rare vagrants
Photos