Giant tortoises are one of the most famous and unique animals of the Galapagos. They are one of the largest living species of tortoise in the world and the official symbol of the islands. The Galapagos Islands were named after the giant tortoise; the old Spanish word galapago means tortoise. Averaging more than four feet in length and weighing in excess of 500 pounds, the life span of these gentle giants can be more than 100 year
Scientists believe the first tortoises arrived in the Galapagos 2–3 million years ago by drifting on debris 600 miles from the coast of South America. It is also believed that prior to the arrival of whalers, pirates and other explorers, the giant tortoises had established at least fifteen separate populations on ten of the largest Galapagos Islands.
Galapagos tortoises are amazingly adapted so that they can survive without food or water for up to an entire year. Unfortunately, this is one reason they were heavily hunted by pirates and whalers—a good source of fresh meat onboard for a long time. The shell shape of the giant tortoises in the Galapagos has evolved based on its location and food source. The two main types of shells are the domed and saddleback. The tortoises with domed shells tend to be larger in size and live on larger, higher islands with humid highlands where food is abundant and readily available. The saddleback shell is found in tortoises that live on the dryer islands. The front of the shell angles upward to allow the tortoise to extend its head to reach vegetation that is higher up, like the pads on tall growing cactus.