Yellow-Legged Gull

On July 2, 2022 we took a birding tour of the Sado Estuary near Lisbon, Portugal with Bernardo Barreto of Birds & Nature Tours in Portugal. We met him in Setubal and then did a clockwise drive around the estuary, eventually driving out the 13 mile long, and less than one mile wide, Troia Peninsula, which separates the Sado River from the Atlantic Ocean, and took a ferry across the 1.5 mile wide estuary, at that point, to Setubal where we'd begun. From the boat I got a photo of a yellow-legged gull. 

There are two subspecies and I saw ssp. atlantis, sometimes known as the Atlantic gull, which could possibly be a species on its own. Additionally, birds breeding on the Atlantic coast of Morocco, Portugal and Galicia, like this one, are usually included among ssp. atlantis, but are sometimes considered a third ssp., lusitanius. These birds have darker wings and back in comparison with the Mediterranean birds. My photo appears to be of a second year bird with a black bill tip and dark eyes (instead of the red bill tip and yellow eyes). I only have one identifier on iNaturalist that confirms it. 

Illustration from Birds of the World. 

Range from Birds of the World.