The same individual but without the use of flash photography. Unfortunately not using flash lead to an exceptionally dark image because the canopy shaded out so much of the sunlight, and it was a cloudy day that day (Whoops!) As a result I had to increase the color exposure in GIMP (hence the strangely dark and murky colors and very bright white of the shell.)
However, this photo does capture what these animals look like when active and alert as they prowl about the forest floor.

Interestingly, the first reaction by this and the other individual encountered on this trip was to run away and it wasn't until it was apparently that they weren't fast enough that they withdrew into their shells. Withdrawal into the shell is not necessarily the first line of defense.