Ah, I see, Reyn. Chocolate turtles wouldn't last long in your pond. Yes, if those turtles are misplaced, it may have something to do with former owners or it may have to do with migration.
Or......flushed down someone's toilet? That would make a good script for a creature film.
THE TAINTED TURTLES THAT ATE UP BRITISH COLUMBIA.
Hmmm. Wonder where Mr. Turtle is this early morning.