The most recognized symbol of the Galapagos is the Tortoise. The islands common name is Spanish for saddle; referring to the shape of the Galapagos Tortoise Shell. With weights over 500 lbs (250 kg) and shells measuring 59 inches (150 cm) Galapagos Tortoises are among the largest on earth. These land-based turtles are slow moving and known for their long life span of more than 150 years.
The Tortoise played an important role in the Theory of Evolution. When Charles Darwin visited the Galapagos Islands, the vice-governor of the Islands told him that he could identify what island the tortoise was from simply by looking at him.
Naturalists believe Tortoises arrived in the islands clinging to a piece of driftwood from a river mouth along the Pacific Coast. A relatively large tortoise, related to the Galapagos Tortoise lives on the South American mainland. The tortoises arrived in San Cristobal then spread throughout the archipelago. Those on individual islands or in isolated parts of the larger islands developed into its own sub-species.
The Galapagos was once home to 15 sub-species of which 11 sub-species still exists. The smallest tortoises like those on Espaņola and Pinta have "Saddle Backs'.
While the largest of the tortoises, those on Santa Cruz and from the Alcedo Volcano on Isabela have "Dome Backs". In this isolated habitat these giant tortoises fill the niche occupied by larger vegetarian mammals in continental regions.
They eat grass and cactus fruit, flowers and stems. Soon after the rainy season the tortoises descend the mountain slopes to feed on the grass covered flats. After that grass withers during the dry season they climb the mountain to feed on grasses of the moist meadows.
When man arrived in the Galapagos Tortoises numbered in the 100,000's. For millennia these animals had gone unhampered by predators. Ideally suited for rugged life in the Galapagos, tortoises are able to survive with little food and water during times of drought.
As the buccaneers, whalers and fisherman arrived in the islands they hunted tortoises as a source of meat. These same men brought pigs, goats, horses and cows whose existence in the islands threatened young tortoises. They ate the little vegetation that existed in the island and their hooves crushed tortoise eggs and the soft shells of young tortoises.
When the Galapagos National Park Service and Charles Darwin Research Station were established in 1969 all 11 remaining species of tortoises were endangered. One of their top priorities was stabilize the environment for the tortoises. This required eradicating the introduced species, encouragement of breeding and rearing of the young.
The Charles Darwin Research Station established a tortoise- rearing project. They have collected tortoise eggs from islands where the species has become endangered from the introduced species. The eggs are brought to the Darwin Station where they are incubated and hatched. The young tortoises are raised until their shells become strong and they can withstand the threat of the introduced predators.
This project, which began in the 1970's has been a success. Of the 11 species that were once endangered 10 species have been brought up to guarded levels. The most noted success story is that of the Espaņola Tortoises. When the project began the Hood Tortoise population consisted of 2 males and 11 females. These tortoises were brought to the Darwin Station. Miraculously a third male was discovered at the San Diego Zoo and brought to the Darwin Station to join the others in a captive breeding program. These 13 tortoises are the parents of over 300 young tortoises now roam free on Espaņola.