Pelicans

A flock of pelicans dropped down out of the sky, gracefully landing on the water. They weren't actively feeding, diving from the air into the water, but there must have been something there to attract them.

 They flapped around as if they were bathing, cleaning their feathers.

 Some appeared to have fish in their bills.

 And poking the water for fish.

 Their wingspan is powerful. You can almost hear the whirl of their wings.