キアシセグロカモメ Larus michahellis

The common large seagull of the Mediterranean and northwestern Africa, as well as the Azores and Canary Islands; uncommon to locally fairly common in northern Europe, mainly in late summer and autumn. Often occurs with flocks of much more numerous Herring Gull and Lesser Black-backed Gull, and, confusingly, appears somewhat intermediate between these species. Adult has medium-gray back (slightly darker than Herring Gull, paler than Lesser Black-backed) and yellowish legs (pink on Herring Gull). Immatures are much like Lesser Black-backed Gull and often not safely identified.