Nerodia erythrogaster
Could be either of the two subspecies, the Red-bellied Water Snake (N. erythrogaster, erythrogaster)
or the Yellow-bellied Water Snake (N. erythrogaster flavigaster).
Distinguishing between the two is very difficult at this distance.
This snake was circling around a number of newly hatched Wood Ducks
Wood Duck Heritage Preserve and Siddique Nature Center
Opelika, Alabama