Size: variation was very marked with 25% of individuals looking very small in relation to the general flock. Garner (1998) confirms that small individuals occur on the Spanish Mediterranean coast, some being smaller than graellsii.

Mantle: the smaller birds are a paler grey than those in the Canaries but still have a distinct blue-grey tinge. They are much paler than graellsii being similar to Common Gull L. canus.

Primaries: on a small sample, only 15% carried a mirror on P9 but 100% had a broad band on P5, a well-established Mediterranean michahellis feature (Garner & Quinn 1997).

Calls: Jonsson (1997) obtained information on the calls of Mediterranean Yellow-legged Gulls from Marbella in eastern Andalucia between Gibraltar and Malaga. He thought that the long calls of the Yellow-legged Gulls in this area sounded like graellsii in tone and rhythm.

Moult in adults: primary moult is commencing in late May with a minority shedding P1.