Many Laughing Gulls, adult and juvenile too. If you view above large, all those big solid white birds in the background are baby Pelicans.
A solitary adult, probably taking a break from the youngsters.
The adults can fly off to fish, or just rest, since juvenile Pelicans are cared for by the entire rookery. I have heard some species of birds in large roosts do that but this was the first time I saw it.