This is a sizable congregation of nonmigratory American White Pelicans photographed at Lake Lewisville. While I watched the initial group was joined by around a dozen additional pelicans flying in from the west.

Wikipedia has this to say about American White Pelicans:

The German naturalist Johann Friedrich Gmelin described the American White Pelican in 1789. The scientific name means “red-billed pelican”, from the Latin term for a pelican, Pelecanus, and erythrorhynchos, derived from the Ancient Greek words erythros (ἐρυθρός, “red”) + rhynchos (ῥύγχος, “bill”).

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory

American White Pelican - Nonmigratory