A giant tortoise is a large reptile native to many tropical islands. Although most known varieties of giant tortoise are now extinct, two main groups still live throughout the world. The giant tortoise can live for hundreds of years, and can reach enormous sizes.
The Aldabra giant tortoise is native to the Seychelles islands off the southeast coast of Africa. The Aldabra Atoll is guarded from use by humans through international protection law, and about 150,000 giant tortoises are believed to live in the archipelago.
They are highly adaptive creatures, able to live in any location on the islands, and seen individually and in herds. Although they spend much of their time on land, Aldabra giant tortoises are excellent swimmers and are believed to be responsible for the subspecies of tortoises throughout the Indian Ocean. The oldest captive tortoise in the world is Esmeralda, an Aldabra giant tortoise who is approximately 170 years old in 2008. An Aldabra tortoise in a Kenyan animal preserve also made news in 2005 when it “adopted” a lonely baby hippo that survived a tsunami.
Galapagos giant tortoises are numerous throughout the volcanic islands of the Galapagos region. Thirteen subspecies of the tortoise are believed to exist, although many are near identical in behavior and appearance. The largest subspecies are capable of reaching weights of more than 660 lbs (300 kg), and may be up to 4 ft (1.2 m) long.
The tortoises of the Galapagos Islands are reptiles, and follow a mostly herbivorous diet. They get much of their hydration through eating cactus and fruit, and can go many days without needing fresh water, although they will bathe in shallow pools to maintain body temperature and possibly for enjoyment. On larger islands, they can often be seen grazing in grass in large herds.
Giant tortoises are believed to reach sexual maturity at age 40, and can mate at any time of year. A female tortoise will dig a deep nest in sandy soil in which she deposits her eggs and covers them. 4-5 months later, the tortoises will hatch and dig their way to the surface, independent from birth onward.
While the Aldabra tortoise is largely successful in terms of population, the conservation status of the Galapagos giant tortoise is listed as threatened by the International Union for the Conservation of Nature and Natural Resources (IUCN). Some subspecies have only a few hundred animals alive, while the Pinta subspecies has only one surviving animal, a relatively young male named Lonesome George. Efforts to find George a mate have been unsuccessful, and it is likely the Pinta species will disappear upon his death.
Despite the work of conservation agencies and the detailed efforts of the Galapagos National Park, the giant tortoises remain endangered. If you would like to help sponsor efforts to protect the populations of one of the longest-living reptiles on Earth, contact a reputable environmental agency to see what you can do. The giant tortoise is a wonderful and fascinating creature, a window into the past, and a hope for conservation of the future.