Mantle: fairly dark with 70% slightly darker than Mediterranean Yellow-legged Gull and 10% as dark as those at Faro. However, 20% were paler being similar to Mediterranean Yellow-legged Gull.

Size: slightly bigger or similar to graellsii.

Structure: legs slightly longer than on some of the Dark form but typical rounded heads, bold head, chest and neck and heavy strong bill with stubby tip.

Primaries: Quite a high proportion of 37% showed a mirror on P9.

Calls: both long and mew calls were graellsii-like.