unidentified gull

unidentified gull

Observation - unidentified gull - UK and Ireland. Description: Can't puzzle out if this is a Great Black-backed, Lesser Black-backed or Yellow-legged Gull. In flight showed a white tail with a sharply-defined broad black terminal band. Gull the same size as Herring Gull but stockier-looking.

Can't puzzle out if this is a Great Black-backed, Lesser Black-backed or Yellow-legged Gull. In flight showed a white tail with a sharply-defined broad black terminal band.
Gull the same size as Herring Gull but stockier-looking.