I took this photo in Jizan, southwest Saudi Arabia in December of a fresh-plumaged gull in juvenile plumage. I thought it could be a Baltic Gull, but the fresh plumage alerted me to the fact it could be something different. As a result, I sent the photo to Klaus Malling Olsen for his comments. He very kindly replied with the following: Baltic is jizzwise different to this bird in showing longer wings and a smaller head, slenderer body and finer bill. The juvenile plumage of Baltic is kept, or almost kept, until birds reach their wintering quarters, so I would expect a Baltic Gull in December not to appear so fresh-plumaged. This indicates a more northerly, Arctic origin of the bird suggesting Heuglin´s Gull. This taxa, is a long-distant migrant, keeping their juvenile plumage on autumn migration, as Baltic do, and start to moult at their arrival to the winter quarters. Heuglin´s Gull breeds very late, at least a month later than Baltic, resulting in very crisp and fresh-looking juvenile well into December, at a time where I suspect most Baltics to appear more worn. There are also other characters leading towards Heuglin´s Gull: the rather big head and bill and compared to Baltic, shorter wing-projection behind the tail. Also, the brown-tinged plumage is more in line with Heuglin´s Gull, being brownish-tinged, whereas most Baltics would have appeared colder blackish-brown in dark parts. The full broad edges to the mantle and scapulars is again a more striking feature against the narrower edges in Baltic, as well as more extensive pale pattern in greater coverts, so all in all, the bird show more characters of Heuglin´s Gull in my opinion (in an always very complex chapter in gull ID).
