A really big one among the gulls and terns

Two weeks ago Riyadh based birder, Mansur Al Fahad paid a visit to the east coast of Saudi Arabia. 

I don't visit the coastline of Eastern Province very often so I was interested in what he would find.

Great black headed gull with four black headed gull

He saw many gulls and terns near Dammam. I am particularly envious about one of his sightings! Among a group of black headed gull was a single great black headed gull a.k.a Pallas's gull.

It was already in breeding plumage unlike the smaller black headed gull which are only just beginning to change.

Its not very common on the Arabian coast but it is so conspicuous by its size that when it does occur it is more often recorded than most other birds.

It is in fact the third largest gull in the world after great black backed gull and glaucous gull. 

I haven't seen one in Saudi Arabia yet. Indeed the last time I saw one was when I used to bird in Azerbaijan four years ago. It was quite common along the Caspian coast.

Slender billed gull

As well as two types of black headed gull, there were plenty of slender billed gull present too.

Heuglin's gull

The birds in the lesser black backed gull complex are very difficult for me to separate and especially so using stand-alone pictures.

My primitive method of separation starts with a comparisons of mantle colours in a mixed group (and in a stand alone picture I can't do this!) . The degree of darkness is in the order: Baltic>Heuglins>steppe>Caspian. We don't usually have to bother with intermedius as an option this far east.

Looking at the top picture on mantle colour alone they have to be either Baltic gull or Heuglins gull. I am minded towards Heuglins gull because the mantle looks decidedly lighter than the upper tail coverts whereas in a Baltic gull the colour is nearly the same.

Please comment if you can help me confirm the bird's ID.

Caspian gull or steppe gull

With this stand-alone picture I could only narrow the choice down to Caspian gull or steppe gull. I posted the picture on BirdForum and the experts there agreed that it couldn't be decisively identified without an open wing picture.

Gull billed tern

No such problems were encountered on identifying the terns. the one above is a gull billed tern. The only possible confusion would be a wintering sandwich tern but the uniform bill colour alone is enough to separate these two.

Lesser crested tern with Terek sandpiper

The final picture is of lesser crested tern heading towards breeding plumage. They seem to be keeping company with a group of Terek sandpiper.

I am not sure I will ever enjoy gull identification and it's made more difficult because I work in Riyadh over 400 kilometres for the coast. I'll try to visit the east coast more often to get more practice.

Sincere thanks to Mansur Al Fahad for providing the pictures which I have heavily cropped in places.