I spent the first week of December in the Algarve, Portugal for a gull-watching trip. One of the aims was to see the Slender-billed Gull Larus genei for the first time. My encounter turned out to be the highlight of the trip with very close views of a group fouraging at the salt pans of Tavira, located between Faro and the Spanish border.
All images were taken on 5 December 2014.
Images of several individuals.
Images of a single individual.
With Black-headed Gull
In appearance, Slender-billed Gulls are very similar to Black-headed Gulls Chroicocephalus rididundus with which I’m very familiar, and it was nice to see one Black-headed Gull among the group of Slender-billeds so that the subtle but distinct differences could be compared. Apart from the obviously slender bill, most striking was the pink/orange iris, the long neck, the (almost) lack of head markings and the distinct pink hue on the body (which doesn’t come across well on the photos).
Also striking was the difference in fouraging behavior: where the Black-headed Gull predominantly picked objects from the surface, the Slender-billed Gulls were targeting their food much deeper in the water, thereby reaching as far down as they could by up-ending without completely submerging, in a fashion reminiscent to dabbling ducks.
The following photo shows an adult Black-headed Gull in the foreground with behind it an adult Slender-billed Gull.
Several individuals (including the first-calendar year shown above) were fitted with a colour ring, originating from Spanish projects. I visited Tavira twice, during which I was able to read 3 different rings.
All images (apart from the ringed individual above) were taken from a car parked next to a salt pan from a short distance (sometimes less than 10 meters). A wonderful experience!