A few gulls pictures from our recent trip below. Full trip report here
The most interesting observation was a large flock of apparent Steppe Gulls, Larus (fuscus) barabensis. According to Peter Adriaens (author of the Gulls of Europe here, also the reference for the photo comments below), these would be the first fully confirmed and documented records for Azerbaijan. Will write up a short note for Dutch Birding with more details, in the meantime here's a few introductory photos below.
2 adult and a first-winter Pallas's Gull - nice and easy to identify!
Second-winter Common Gull, the extensive black in the wing, lack of mirror on p9, a relatively large dark mark on p4 and dark markings in the tail (there may even be a couple of dark markings in the secondaries) could indicate Russian Common Gull although the head doesn't appear particularly white or shawled (a distinctive boa). The bill also doesn't appear particularly yellow which is indicative of Russian Common Gull. A diagnostic second-winter Russian Common Gull should have a combination of features that includes the white head and boa, yellow bill, black marks on inner and outer webs of p4, a lack of mirror on p9 (or confined to inner web), no white tongue-tip to p7 and a blunt tip to black wedge on outer web of p7. This bird doesn't show all those features so is presumably an intergrade.
First-winter Common Gull (Vincent Legrand). The bright bill, clean white underparts, white underwing with dark broad primaries and secondaries trailing edge and shawled neck suggests Russian Common Gull . A less marked underwing and a more white head with a distinctive boa would be more typical of Russian Common Gull.
Adult Caspian Gulls. Ironically the Caspian Gulls in the Caspian Sea are not as distinctive as the western populations of Caspian Gulls (also known as 'Pontic Gulls'). The Western birds have more white in the primaries whereas those in the Caspian Sea have more variable and often more extensive black in the wing-tips
Adult Caspian Gull (Vincent Legrand) 7 marked primaries (usually 6) but characteristically has the long white tongue on p10 and grey tongues with white tongue tips on other primaries too
Adult Caspian Gull (Vincent Legrand), showing 8 primaries with dark markings . Also the tongues on the outer primaries are not typically long. A bird like this could be considered within variation of Caspian Gulls in this region but there were also suggestions of an intergrade type between Caspian and Steppe Gull.
An adult Caspian Gull landing in a flock of apparent Steppe Gulls, showing the paler upperparts, extensive pale tongues in the primaries with white tongue tips, pale tip to p10 and the duller coloured legs
Presumed adult Heuglin's Gull (foreground) within a flock of mainly apparent Steppe Gulls (and some Caspian Gulls). Looks like a few other Heuglin's Gulls in the background and perhaps a 2nd winter Caspian Gull (duller legs and perhaps slightly lighter upperparts) second bird left of foreground Heuglin's.
Presumed Heuglin's Gull (above and below) by Vincent Legrand. Identification based mainly on location (although graellsii has recently been confirmed in Israel from a ringing record). Also the white tips to the grey tongues on the primaries are indicative of Heuglin's Gull. A more typical wing-tip pattern for Heuglin's Gul is a the p10 mirror separated from the tip by a broad black subterminal band (so the mirror sits far from the wingtip) and no mirror on p9. Also on the underside (below) the tongue to p10 is typically white (it's grey on this bird).
We came across this very interesting flock of gulls (above and below) near Baku on the way back from the Caucasus. The upperpart colour was pretty dark, seemingly darker than expected for Caspian Gull with a dark bluish-grey upperpart (more pale grey in Caspian) but not as dark as the presumed Heuglin's Gulls in the flock (of which there were several). The bright yellow legs were also not right for Caspian Gull (Caspians have dull yellow legs even in summer plumage) and are more indicative of Steppe Gull.
Some interesting immature plumages in there too. First-winter Steppe and Caspian Gulls are virtually identical.
One Heuglin's Gull (centre right) and apparent Steppe Gulls- the amount of black in the wing on the apparent Steppe Gulls is too extensive for typical Caspian and the tongue on p10 on some birds in short and wide (a feature of Steppe Gull). 7 primaries have dark markings on most of these birds and the p10 mirror is separated from the tip by a broad black band. The black on the outer webs of the outer most primaries also typically reaches further to primary coverts with short grey bases (unlike Caspian).
Heuglin's Gull (centre right) and apparent Steppe Gulls
More shots of the same group, apparent Steppe Gulls and a few Heuglin's Gulls
Presumably a first-winter Steppe Gull (left centre), although some of these first-winter birds in this flock could also be Caspian or even Heuglin's Gull which are also similar. Unfortunately we couldn't get many better photos of these birds because we were moved on by security as these gulls were resting in a police controlled area (a prison or military area).