Galápagos tortoise
From Freepedia
| Galápagos Tortoise | ||||||||||||||
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| Geochelone elephantopus (Quoy & Gaimard, 1824) |
The Galápagos tortoise (or giant Galápagos tortoise), Geochelone elephantopus, is the largest living tortoise. It can weigh over 225 kg (500 pounds) and measure 1.8 m (6 feet) from head to tail. It is a very slow-moving animal, moving only 0.25 km/h (0.16 miles per hour). It is an herbivore, eating grasses, plant leaves, cacti and fruits.
The Galápagos tortoise has a very large shell (or carapace) made of bone. The shape of the carapace and other morphological features are indicative of the terrain the animal inhabits. Highland areas with lush vegetation near the ground are normally home to tortoises with domed shells; these animals have restricted upward head movement due to shorter necks, and tend to have shorter limbs as well (see photo). Coastal regions with less vegetation at ground level are inhabited by tortoises with saddle-back shells; their extended necks and limbs help them to reach food higher off the ground. Shells can also be of intermediate type, with characteristics between domed and saddle-back types. These features played an important role in the development of Charles Darwin's theory of evolution.
The Galápagos tortoise is found on the Galápagos Islands just west of Ecuador in South America. Because of the 250,000 tortoises that inhabited the island, Spanish explorers named the islands Galápagos for the giant tortoises. Today only 15,000 are left, mainly due to action of whalers and pirates that killed them for food during the 18th and 19th centuries. Turned on their back where they could not move the Galápagos tortoise could survive for months without food or water making them a good source of fresh meat before refrigeration. Their dilute urine could also be used as drinking water.
Research has shown that there were probably fourteen subspecies of Geochelone elephantopus. Now only eleven subspecies remain, five in each of the five volcanoes of Isabela island, and the other six at Santiago, Santa Cruz, San Cristobal, Pinzón, Española and Pinta. The Pinta subspecies is likely due to become extinct as only one single male, known as Lonesome George, is known to be alive (though the possibility of other individuals remaining cannot be completely discounted).
One of the oldest living specimens is a giant Galápagos tortoise named Harriet in the Australia Zoo at Beerwah, Queensland, Australia. Its estimated date of birth is 1830. Galápagos tortoises may live to an age of 120-200 years or more.
This article incorporates text from the 1911 Encyclopædia Britannica, which is in the public domain.
See also
- Chambers, Paul. A Sheltered Life: The Unexpected History of the Giant Tortoise. John Murray (Publishers), London. 2004. ISBN 0719565286.
- Lonesome George
External links
- American Museum of Natural History, Galapagos Giant Tortoise webpage
- National Geographic article on Harriet
