Common winter visitor and passage migrant. Close relative of the Baltic Gull. The immature birds, all brownish-grey coloured, are especially difficult to distinguish in the field.
Where in Kuwait
One of the more common dark-backed Gulls found in mixed flocks along the coast over the winter months
In the world
There is much debate on the large white-headed gull taxa and according to Birdlife International "The following species level treatment, shown with sub-specific placements, has been adopted by the BTWG: L. fuscus (with intermedius, graellsii, heuglini, taimyrensis and barabensis); L. argentatus (with argenteus, smithsonianus, vegae and mongolicus); L. michahellis (with atlantis and armenicus) and L. cachinnans".