A visit to a preserve for Galapagos tortoises on Santa Cruz Island allowed for some up close encounters with these huge animals. Feeding at ground level on grasses and just about anything green, each tortoise mows down a wedge-shaped area in front of them, then take a couple steps forward and begin munching again. What struck me was how very elemental the process is that sustains these 200-400 pound animals that can live for over a century.