Gaviota de Kamchatka vs Gaviota Groenlandesa

The Slaty-backed Gull and Iceland Gull can be distinguished primarily by their plumage and size. The Slaty-backed Gull has a darker mantle and more robust build compared to the paler Iceland Gull. Observing these features in good light can aid in identification.

Look for the darker mantle of the Slaty-backed Gull compared to the paler Iceland Gull. Size can also be a clue, with the Slaty-backed Gull being larger and more robust. Observing these features in good lighting conditions is crucial.

The Slaty-backed Gull is generally larger and more robust than the Iceland Gull.

The Slaty-backed Gull has a darker slate-gray mantle, while the Iceland Gull is paler with a lighter gray or even whitish mantle. The Iceland Gull also shows more variation in primary feather markings.