Hi Norm,Thanks for your comment. Vega Gull (Larus vegae) is cleraly very similar to Herring Gull (Larus argentatus) and I would be enormously impressed if anyone managed to positively identify one in Europe (or, conversely, for Asian birders to positively identify a European Herring Gull' in Asia). The issue is that there is a great deal of variation in the Herring Gull complex and it is very difficult to say for sure that a given gull is within variation for vegae and outside the variation of argentatus. I don't have any experience with American Herring Gull, so it is difficult for me to comment on that species. However, there are features of vegae that are, on average, subtly different to argentatus. For example, in my experience (on adult birds):- structure of vegae is, on average, heavier than argentatus- white tertial band tends to be larger on vegae- eye-ring tends to be more reddish on vegae than orange-yellow on argentatus- legs tend to be brighter (more raspberry') pink on vegae than on argentatus- black on wing-tips tends to be stronger, often reaching p4 (unusual on argentatus 2 per cent according to Olsen and Larsson); white spots on primaries at rest tend to be smaller than argentatusI should add that I thought the mantle colour of vegae looked very similar to argentatus (perhaps slightly darker than the British argenteus).Of course, there is great variability, so one must be very careful but if I found a gull exhibiting all of the above features in Europe, I would look at it very closely (and take lots of photos!).As to whether it should be a full species, I shall leave that to the experts I don't know enough about the range of vegae and whether or not it overlaps with Herring Gull or American Herring Gull and, if so, how common hybrids are etc Best wishes, Terry