Galapagos Tortoise :: WLR:- The Galápagos tortoise or Galápagos giant tortoise (Chelonoidis nigra) is the largest living species of tortoise, reaching weights of over 400 kg (880 lb) and lengths of over 1.8 meters (5.9 ft). With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates. A captive individual lived at least 170 years.
The tortoise is native to seven of the Galápagos Islands, a volcanic archipelago about 1,000 km (620 mi) west of the Ecuadorian mainland. Spanish explorers who discovered the islands in the 16th century named them after the Spanish galápago, meaning tortoise.
Shell size and shape vary between populations. On islands with humid highlands, the tortoises are larger, with domed shells and short necks. On islands with dry lowlands, the tortoises are smaller, with "saddleback" shells and long necks. These island-to-island differences played a role in the inception of Charles Darwin's theory of evolution.
The tortoises are herbivores that consume a diet of cacti, grasses, leaves, lichens, and berries. They have been documented to feed on Hippomane mancinella ('poison apple'), the endemic guava Psidium galapageium, the water fern Azolla microphylla, and the bromeliad Tillandsia insularis. A tortoise eats an average of 32–36 kilograms (70–80 lb) per day, though inefficient digestion means that much of this passes through without nutritional extraction.
Tortoises acquire most of their moisture from the dew and sap in vegetation ; therefore, they can spend long periods without drinking water. They can endure 18 months when deprived of all food and water,[80] surviving by breaking down their body fat to produce water as a by-product. When thirsty they may drink large quantities of water very quickly, storing it in their bladders and the "root of the neck" both of which used to make them useful water sources on ships. On arid islands, tortoises lick morning dew from boulders, and the repeated action over many generations has formed half-sphere depressions in the rock.
The tortoise is native to seven of the Galápagos Islands, a volcanic archipelago about 1,000 km (620 mi) west of the Ecuadorian mainland. Spanish explorers who discovered the islands in the 16th century named them after the Spanish galápago, meaning tortoise.
Shell size and shape vary between populations. On islands with humid highlands, the tortoises are larger, with domed shells and short necks. On islands with dry lowlands, the tortoises are smaller, with "saddleback" shells and long necks. These island-to-island differences played a role in the inception of Charles Darwin's theory of evolution.
The tortoises are herbivores that consume a diet of cacti, grasses, leaves, lichens, and berries. They have been documented to feed on Hippomane mancinella ('poison apple'), the endemic guava Psidium galapageium, the water fern Azolla microphylla, and the bromeliad Tillandsia insularis. A tortoise eats an average of 32–36 kilograms (70–80 lb) per day, though inefficient digestion means that much of this passes through without nutritional extraction.
Tortoises acquire most of their moisture from the dew and sap in vegetation ; therefore, they can spend long periods without drinking water. They can endure 18 months when deprived of all food and water,[80] surviving by breaking down their body fat to produce water as a by-product. When thirsty they may drink large quantities of water very quickly, storing it in their bladders and the "root of the neck" both of which used to make them useful water sources on ships. On arid islands, tortoises lick morning dew from boulders, and the repeated action over many generations has formed half-sphere depressions in the rock.
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