First a few oddities at Dafundo, from the last month...
Could 2nd winter Ylg have such a window panel on wings?? P1 to P4 are pale on both webs, I thought that was a trait of Herrings and Ylg show in the majority of cases only inner paler web, but such a well marked bird on saddle and coverts seems better for Ylg allmost resembling Gbbg pattern. Structure also seems to point out Herring, with heavy belly and not so slender as our lusitanius, but the nominate species from the Mediterranean should allways be considered.
Some graellsii tone scapulars seem to show a large male Lbbg, with some kind of leucism, or even some Gbbg influence, tertials have large white end like marinus but primary projection was to long for the species. It was an heavy built gull, but not hudge.
Not the most usual 1st winter Yllg Larus michahellis at Dafundo, probably a bulky male from de Mediterranean, with moulted greater, median and lesser coverts.
1st winter Yellow Legged Gull Larus michahellis
2nd winter Yellow legged Gull Larus michahellis
1st winter male Great Black Backed Gull Larus marinus
Trying to digest a conger eel...