These are not fighting, they are Fulmars, the bird on the right was sitting on the nest, probably on an egg. The other bird had just flown in and they were very loudly saying hello. Much squawking, and screaming went on but they are a pair.
Fulmars take a long time to incubate their egg, I think it is about six weeks. Another thing to remember is don't go to close to a sitting bird. Upset them, and they will projectile vomit an evil fishy, oily, really foul smelling fluid, that is almost impossible to remove from clothing. You have been warned.
