Aldabra Tortoise

ORDER: Chelonia

FAMILY: Testudinidae

GENUS: Geochelone

SPECIES: gigantea

DESCRIPTION:

Hind legs are cylindrical and columnar like those of an elephant. Forelegs have anterior surface covered by thick, often bony scales. Toes are short; two-jointed. Snake-like neck and legs are retractile. The very small pointed head is covered with scales. High domed gray shell can measure up to 56” in length. Weight to 560 pounds. Males are larger than females and have longer, thicker tails.

GEOGRAPHICAL RANGE AND HABITAT:

Aldabra Island in the Indian Ocean, near the Seychelles. They live in grasslands, scrub areas and mangrove swamps.

DIET:

Strictly herbivorous and eat grasses, sedges, herbs, and woody plants. In captivity, feed on great quantities of cabbage leaves and other green stuffs.

LIFE CYCLE/SOCIAL STRUCTURE:

Normal breeding season is from January to April. In courting, the male batters his shell against a female a dozen or more times and he makes a deep, trumpeting call when mating. After carrying the fertilized ova for about ten weeks, the female digs a hole in the ground and buries 9 to 25 spherical, tennis-ball-sized eggs. The incubation period ranges from 73 to 160 days with the young emerging during an eight-week period coinciding with the beginning of the wet season. New-born are very small; after 18 months they are still no bigger than a man's fist and weigh less than three ounces. The carapace is soft at first. Growth continues for forty years. Oldest recorded age is 152 years.

SPECIAL ADAPTATIONS:

Carapace has small neck plate absent in other species. Able to go without food for several weeks.

INTERPRETIVE INFORMATION::

Wallows in mud to protect against mosquitoes. In captivity, they quickly learn to recognize their keepers. Knife-like jaws could easily crush a person’s hand. They seldom breed in captivity, unlike the Galapagos Tortoise. Conical “pyramiding “ of the carapace scutes is a common growth defect in captive tortoises, related to a dietary deficiency and possibly to too-rapid growth.

OUR ANIMALS:

3 Males. 3 females. Our oldest male is probably over 100 years old and came here from Germany in 1977.

STATUS IN THE WILD:

Endangered and protected on Aldabra. Small populations have been introduced to neighboring islands and are also protected. Of the four races of giant tortoises once present on islands in the Indian Ocean, only the Aldabra Tortoise survived beyond the beginning of the 19th century. In the late 1880’s Charles Darwin and other eminent naturalists signed a formal petition with the hope of saving the Aldabra Tortoise, which led to their protection.

BIBLIOGRAPHY:

1. Alderton, David. 1988. Turtles and Tortoises of the World. Facts on File, Inc, NY.
2. Ernst, Carl and Barbour, Roger. 1989. Turtles of the World, Smithsonian Press. Hayes, Alycin. “The Aldabra Tortoise: Land Giant”, Reptile and Amphibian Magazine, March/April 1994.