09 December 2012

Heuglin’s Gulls – Al Khobar Corniche

The Al Khobar Corniche site had a hundred plus Large White-headed Gulls (LWHG) of which 17 were Heuglin’s Gulls Larus heuglini. Heuglin’s Gull is relatively common in the Eastern Province of Saudi Arabia, with about 15% of all large white-headed gulls being this taxon, so this gathering had a larger percentage of Heuglin’s Gulls than would be expected. They are an uncommon passage migrant and winter visitor to the Eastern Province of Saudi Arabia with numbers only generally being seen from October and building up during November and December with most birds departing by mid-March. They can be identified by their more aggressive, fierce look and come from the far north compared to Steppe Gull Larus barabensis. Due to their far northern distribution the time juvenile birds are exposed to the desert climate is relatively short and this can be seen with the white notching on the juvenile wing-coverts and the feather tips in general being in better condition (less worn) and the brown parts being less bleached in 2cy heuglini than 2cy barabensis. In March many heuglini are shaggy headed, show neck spots and are still re-growing P10 so are rather different to Steppe Gull. Heuglin’s Gull in adult plumage is not as jet-black as fuscus, but still a darker shade of grey than the widespread Steppe Gull. On geographic grounds, anyone encountering birds with mid to dark grey upperparts in the Middle-East (birds paler than the fuscus but slightly darker than the barabensis that also winter in the region) can be reasonably confident with their identification as Heuglin’s Gull although paler heuglini are more difficult to identify. The separation of immature heuglini from barabensis is far from clear and in many cases it is difficult to demonstrate conclusively that images of heuglini on the wintering grounds are not barabensis. Heuglin’s Gull is currently included with Lesser Black-backed Gull Larus fuscus (polytypic, including fuscus, intermedius, graellsii, heuglini, taimyrensis, barabensis). The below photographs show two adults at the top and a third calendar year bird at the bottom.