Sparrows, a crowded community when they come to my feeders, due to nature of the bird or circumstance of an introduced species which has perhaps been overly successful, tend to move in an arrow shape when eating seeds on the ground: one to the fore, rest in a spread behind.
Sometimes they scatter at random and feed but if disturbed into flight (and they are nervy birds which seem easily socialized if you watch those around outdoor patios) they return again in the protected shape. I wish I could tell if the one out front is always the same!