© A. R. Dean

Note typical structure, with long primary extension (creating attenuated rear end), and relatively smaller head and finer bill compared with Herring Gull.
Tertials have solidly dark bases and just slightly notched, neat pale margins to outer 50%.
Juvenile mantle, scapular and covert feathers have solidly dark centres, with neat margins, especially to scapulars.
Bill all dark, though base with just slightly 'greyer' tinge (partly a function of light). See also juvenile Herring Gull and juvenile Caspian Gull.