This is Spunky's brand new habitat, and our first geodesic dome.
The preserve is in Florida, so the climate is great for him most of the year, but in the winter months it can get in the 30-50 range often. So the pond in his dome is made with piping inside the concrete that gets heated water pumped through it heating the concrete. He can now go into the pool when it is cooler outside, and maintain a higher body temperature.
Also, the hollowed out tree has the water pipes running underneath it, so it's pretty warm in there as well.
He seems pretty happy with his new dome, and he goes in the water far more than he used to in his old habitat.
You can see more pics of spunky and his new habitat at