Gulls

I took quite a few pictures at low tide yesterday of the waders and spent today trying to identify them. Not having had waders (or ever noticed any) in Johannesburg, I have been struggling with sandpipers, curlews greenshanks, plovers you name it and am now even more confused. So as a result I haven't been outdoors today (well the wind's blowing gales as well - not my cup of tea) so I popped my head out the window and took this picture of a ....well is it a black head or grey head gull? So simple when you're an expert but when you've lived inland all your life and not an expert on gulls it's not easy. I suddenly started noticing all these gulls with black heads lately - apparently that's because they're breeding. Well I've got to keep my brain busy with something so might as well learn about sea birds while I'm in Bahrain.