I'm with you. The bird thing is not probable. Thinking back now I wonder if the mystery stocker of that pond wasn't a broken field drain tile. The farms in that area all have drain tiles and they all lead to the river.....
That's not it. My property backs up to an exclusive neighborhood that is said to be the highest point in Caddo Parish. There are no ponds in the neighborhood, therefor there are no bodies of water within miles that are higher in elevation than my pond.