Grey-headed Gull (Chroicocephalus cirrocephalus)

I was very pleased today when I discovered that I had photographed a couple of Grey-headed Gulls  during my stay in South Africa recently.  I have mentioned before that I always like to photograph different species of gulls when I am away and I did notice at the time that there was something a bit different about one or two  birds amongst a large flock of Hartlaub's Gull that were bathing in a fresh water pool.  As I sorted through my images I could immediately see that this bird was different.  It lacked a red eye ring and also the beak was a subtly different shape and colour.   You can make some comparisons in these two photos. 

A Grey Headed Gull, this one without any hint of grey on the head but you can significantly see a difference in the wing pattern.