Galápagos have been famed for their giant tortoises ever since the discovery of the islands. They can weigh up to 550 pounds and measure almost 5 feet over the curvature of the carapace. Once numbering in the hundreds of thousands, the tortoise population was sharply reduced by 19th-century whalers and fur sealers, who discovered these gentle, defenseless giants to be excellent sources of fresh meat for long voyages. © Douglas Steakley