In one day, I was able to observe a pair of mating parrot snakes and a parrot snake preying on Lithobates (Rana) forreri.  As a disclaimer, the frog was tossed toward the snake out of curiosity by another student here, Paul, so it wasn’t a ‘real’ predation event.  Mahmood, however, suggested that this species of snake hunts for frogs, such as L. forreri, in the leaf litter during the day, while the frogs are inactive.