This is a bird I hope to be better acquainted with. I have seen them in NC on pelagics and in California but it has been a couple years and I miss them. They are the elegant version of a jaeger which is not easy to accomplish for a bird that makes it's living as a pirate. The Jack Sparrow of jaegers. I was hoping to see some in Norway on breeding grounds but alas I came up short.
Note the small bill as far as jaegers go, and the hint of the tail streamers forming on this young bird. This one was on a Patteson Pelagic out of Hatteras.