Yellow-legged Gull

The Yellow-legged Gull is a relatively large, robust gull, not very tall on legs, in size roughly similar to that of the Herring Gull and the Black-headed Gull. Sexual dimorphism only plays out in size, with the male being significantly larger than the female. Identification of adults in nuptial plumage presents no problem when well seen. It is grey on top and white underneath like the others. It is the shade of the grey of the upper parts that is important. The grey of the nominate subspecies of the Yellow-legged Gull, the michahellis, is intermediate between that of the Herring or Black-headed Gull, a little lighter, and that of the Lesser Black-backed Gull, distinctly darker. Then follows the color of the bill and legs, which in the Yellow-legged Gull is a bright yellow in the nuptial period. The bill has an important aspect, is stouter and taller than in the others. It has a red patch at the lower mandible at the gonydeal angle, like all large gulls, but may perhaps be brighter in this one and more diffuse on the adjacent upper mandible. The corner of the bill is likewise red. The eye has a light yellow iris, which makes it well visible, and it is surrounded by a bright red orbital circle. On a flying bird, one must pay attention to the pattern of the end of the wing. The 5 last primary remiges (numbered in descending order, P5 to P10) grey have black at their tip, in decreasing quantity from P10 to P5. To this end of the wing, one must note the distribution of the white, which is specific. The outermost/anterior one, P10, largely black, is white at its tip, with a small black subterminal bar sometimes absent. P9 reproduces a similar scheme but the white tip is less long and the subterminal black bar much more important, thus inverting the proportions in favour of the black. Finally, the P8 to P5 have less and less black and just have a white spot at their tip.The atlantis subspecies of the Macaronesian Islands has much darker upper grey, approaching that of graellsii ssp G. brun, from which possible confusions arise. The Yellow-legged Gull becomes adult in its fourth year, passing through complex immature plumages that are quite close to the equivalent plumages of other species, making it difficult to sort out. Therefore, we will not approach this subject by risking confusing the reader, and send them to the images of the gallery, which are self-explanatory. Suffice it to say that the shade of grey in the upper parts, once it appears in the second year, is of great importance in the analysis.
Let's simply look at the newly fledged juvenile. It appears brown with a pale head. The upper parts are brown, darker than the young silver and paler than the brown. All the feathers have a whitish-beige edge, giving a clearly scaled appearance. The tertials, same brown, have a whitish and serrated edge that is well visible. The underparts are whitish and mottled with light brown on the chest and flanks. The head and neck are finely striped of the same colour, explaining their lighter aspect. The dark eye is set in a darkened area with a dark brown arch in front of it. The bill is blackish and the legs are rosy. In flight, note the wing pattern. The remiges are dark brown without a clearer window marked at the level of the inner primaries. In the overhead view, the outer coverts are darkened, outlining a second dark wing band that partially doubles the full dark band of the secondary remiges. The young silver has a clear window and a single dark bar. On the other hand, the young Pontic can easily be mistaken for this age. It has a very clear underside of the wing while the leucophée has a distinct brown.One must also take into account the shape (higher on legs, more bulging chest, longer neck, receding forehead) of the Yellow-legged Gull.