Laughing Gulls (Leucophaeus atricilla) in flight in Corpus Christi, Texas. When I was a kid, we had many seagulls that looked like these back in Scotland and we always just knew them as “Black Headed Gulls”. It seems, though, that there are several different species of black headed gulls because the Scottish ones are apparently Chroicocephalus ridibundus instead. I live and learn (with the help of Google).
For the technically inclined...