I went to Portugal to look for intermedius Lesser Black-backed Gulls. I found those, but was bewildered by the abundance and variation in both Lessers and Yellow-legged Gulls. Neither species proved to be as easy to understand as I expected.
Since then, several fine articles on Yellow-legged Gull identification have been published: Gruber's in Limicola (June 1995), Garner's in British Birds (January-February 1997 and September 1997), and Jonsson's in Alula (March 1998). All of these mention the forms that occur in Portugal, the "Atlantic Iberian" and the "Cantabrican," as well as the more widespread michahellis. Briefly, the Atlantic-Iberian is close to atlantis, and may be the same thing. They are smaller and darker than michahellis. The Cantabricans are equally small but paler than michahellis. I belive that I saw both of these in Portugal (the Atlantic-Iberian are the norm and are very common) as well as michahellis. You will find here photos of all three (probably), of all ages. On the first winter birds, note the anchor marks on the scapulars. Two of these birds did not have especially pale heads.
|Intermedius and first winter YLGU||First winter YLGU||First winter YLGU|
|Intermedius, three graellsii, adult and 3rd winter YLGU||First winter YLGU with odd tail||Second winter and first winter YLGU|
|Third winter YLGU||Third or fourth winter YLGU|
|Adult michahellis||Possible Cantabrican|
since February 4, 1999