John, you are my hero. I really admired your previous Island project and always intended to model after it at some point but now you've really outdone yourself with this awesome turtle island. Mine was more of an easy experiment and I didn't bother to stain it or anything. Just a matter of time before rot sets in I would imagine. Yours is going to last the test of time I have a feeling.
Regarding turtles leaving the pond.. I've had this happen a lot over the years. When my girlfriend moved in and she started naming the various turtles and picking favorites, I warned her that turtles tend to develop an inexplicable wanderlust regardless of how well they have it and to try not to get attached to them. We feed them well with pellets and treats every day, they have a fountain and a basking platform, not to mention everything is safe and fenced. Turtle paradise. Well, her favorite turtle she named "Lisa" had been in the pond for over 3 years. One day she started acting quite strange wandering around land. The next day she was gone. 2 months later we are feeding the turtles out on the bridge like we always do, and suddenly there was Lisa who had returned. Where she went, we don't know, but somehow she came back.
It must be a survival/propagation instinct in the species. No matter how good they have it they must go to new places.
Kevin993 they may have wanderlust other than what I know of, but the males do move around to find females and the females do move around to lay their eggs on land. At least the Redear sliders do. Had a couple baby redears last year and several this year. Around the farm have seen the females digging holes to deposit eggs and we have found hatched redears and snapper babies in large mud puddles.