Whilst out looking for Large White-headed Gulls (LWHG) in late January we came across a small number on a beach in Al Khobar. The light was very poor due a large dust storm but I managed to take a few photos of at least two of the birds present. These birds were Heuglin’s Gulls Larus (fuscus/heuglini) heuglini which is not the commonest Gull in Saudi Arabia, with about 8% to 10% of all LWHG being this taxon. On geographic grounds, anyone encountering birds with mid to dark grey upperparts in Saudi Arabia (birds paler than the fuscus but slightly darker than the barabensis that also commonly winter in the Kingdom) can be reasonably confident with their identification as heuglini.
· Large gull often bulky looking, although smaller slender birds do occur
· The upper-part grey tone is normally much darker than cachinnans & barabensis and slightly darker than armenicus, being slate grey in heuglini making it the darkest of all Saudi Arabian large gulls with the exception of fuscus
· Normally show extensive head streaking in mid-winter, most concentrated on the hind-neck, but sometimes continues on the side-neck, creating a collar of fine streaks. Nape and back of the head often show brown spots or drops until late January after which the nape becomes whiter and more faintly streaked.
· Many birds show a fierce facial expression, accentuated by the dark head streaking and relatively steep forehead.
· Bill is slender and long without an obvious gonydeal angle and with the gonys spot being orange-red, not as deep coral red as in western LBBG taxa. The orange to red gonys spot often does not reach the upper mandible. The base of bill is sometimes a bit flesh-coloured, but can be brighter yellow on some birds. There are often dark markings on the bill more prominent than on other LWHG, at the tip, often on both mandibles and sometimes a complete bill-band in winter.
· Has narrow triangular nostrils
· Legs are long and thick, often straw yellow, sometimes a bit flesh-coloured, but can be brighter yellow on some birds occasionally with fleshy tinge often on the feet.
· Eye is normally pale yellow with a red orbital ring, sometimes orange (5%). Rarely the eye is dark flecked giving a dark eyed impression.
· Black on primaries usually to P5 & P4 and sometimes to P3, showing medium amount of black on the wingtip for a Saudi Arabian LWHG. Normally shows a large white mirror on P10 & often a smaller mirror on P9 with clear contrast between black of wingtips and rest of upperparts.
· Late moult timing of the primaries. They often have the outer primaries still growing in January and February (moult sequence they share with nominate fuscus). In contrast the primary moult of armenicus, cachinnans & barabensis is normally finished by December, and the primary tips can already show some wear by this time, unlike the new primary tips shown by heuglini.
Sub-adult birds normally show similar plumage to adult birds, although a number of birds show immature features such as a presence of broad dark centres to the greater primary coverts with the centres broad brownish-black and the tips pale whitish. Other indicators may be some black still be apparent in the rectrices and an obviously broad bill band. These features can also be shown on some adult birds as well, however, so aging often not possible with 100% certainty.
