West-central and Northwest Thailand, Feb/March 2016
From February 21 - March 05, 2016, Sheridan, Willlie Sekula and I spent fifteen days in the west-central, north-central, and northwest parts of Thailand, expertly led by Dave Sargeant of Chiang Mai.
We visited Pak Thale, Laem Pak Bia, Nong Pla Lai, Kaeng Krachan, Bueng Boraphet, Mai Ping, Doi Inthanon, Mae Taeng, Chiang Dao, Fang, Doi Lang, and Doi Ang Kang.
Possible Steppe Gull (Larus [fuscus] barabensis). This individual had been seen by others for at least a week prior to us arriving at the tip of the sandspit at Laem Pak Bia on February 26th. There had been up to five fairly typical heuglini present but I only saw two heuglinis, (they appear in some of the images below, along with Pallas' Gull) neither of which was a full adult. I feel that this bird has good credentials for barabensis (see below), but I have no images of the open wing, and my photos are not good enough to confirm some of the key features; I saw some photos taken by others that are much better than mine.
- only a tiny amount of thin winter markings present at the rear base of the neck - invisible at a distance. This seems typical for barabensis in late Feb, while heuglini typically has significantly more nape/rear-neck streaking well into mid-March.
- the bill has a clean black subterminal band (as on armenicus) - more typical for adult breeding barabensis than for heuglini.
- the legs/feet are bright yellow. I spent a week gulling in Bahrain in mid-March 1999, and one of the quick ways to spot a barabensis among the other large gulls was to look for bright yellow legs. Most heuglini had dull yellowish legs with varying degrees of flesh tones (especially on the feet). Among the scores of heuglini I saw, only two or three had bright legs, and none of those birds (in breeding plumage) had a thick black subterminal band on the bill.
- the mantle shade is slightly paler than on the two heuglinis. Not really much help, since my comparative sample is tiny and are non-adults.
NOTE: in the last image there is the suggestion of a pale tongue visible as the base of P10; I am not certain if this white mark is a tongue, but if it is it would be wrong for barabensis and heuglini, and would point much more towards - what??