The Nelson's Gull is a hybrid between a Glaucous Gull and a Great Black-backed Gull. It took a great deal of head scratching to identify this example and its probably still up for debate.
This much is certain. This hybrid is equal in size to a Glaucous Gull/Great Black-back Gull so hybridization with smaller gulls such as; Lesser Black-backed Gull, Ring-billed Gull and Iceland Gull can be ruled out. Note also the massive bill typical of a Glaucous Gull. Nevertheless hybrids are always tricky.
Nelson's Gull
