The odd thing about Black headed gulls is that they don't always have a black head!
All about Black-headed gulls - Cornell
Black-headed gull - BTO

Dozing black headed gull

Wing stretch
When we lived in Caerphilly in S. Wales we had a man-made lake or pond right next to the house and it gave me plenty of opportunities for photographing the many Black headed gulls that visited regularly.

Taking the plunge
They do have a beautiful wing shape.

Gear up

Lift off

Splish splash
You can see these gulls almost anywhere these days, their high pitched screech is quite easy to identify.

Screeching bird

Morning breath