The Mediterranean Gull should really be called the Black-headed Gull. As you can see, the head is jet black rather than the chocolaty colour of the Black-headed Gull. There is also no black tip in the wing for adult Mediterranean Gulls.
Ferrybridge had lots of Gulls out on the mud. This Black-headed Gull is definitely different to the Mediterranean Gull.
A stop at Radipole resulted in some nice pics of common birds. A Common Tern was fishing just by the bridge.
Probably the closest I have ever got to a Herring Gull, informally known as the Seagull.