What is a Giant Tortoise?

Jessica Ellis
Jessica Ellis

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 Galapagos Islands are home to giant tortoises.
The Galapagos Islands are home to giant tortoises.

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.

Some giant tortoises can weigh hundreds of pounds.
Some giant tortoises can weigh hundreds of pounds.

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.

The giant tortoise is native to a variety of tropical islands.
The giant tortoise is native to a variety of tropical islands.
Jessica Ellis
Jessica Ellis

With a B.A. in theater from UCLA and a graduate degree in screenwriting from the American Film Institute, Jessica is passionate about drama and film. She has many other interests, and enjoys learning and writing about a wide range of topics in her role as a wiseGEEK writer.

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Discussion Comments


Another interesting fact about the giant tortoise is their habitual patterns. They sleep at a specific time and in the same specific place. It is said that they never change where they sleep. In addition, their nesting grounds are always the same. The female tortoise will return to same spot every year to lay her eggs.

Regarding the Galapagos tortoise, it has been suggested that, among those remaining on the island, one could possibly be a hatchling from 1835 when Charles Darwin visited the islands. Many argue that there is no truth to that but who knows?


In one of my science courses, we had to pick an endangered species and do a report on it. I chose to do mine on the giant Galapagos tortoise. I was fascinated with everything that I learned and have since become very active in their preservation.

One of the things that I found fascinating was how they breathe. Since their shells are so big, it prevents the tortoise from being able to expand its chest to breathe. However, they have special muscles for the sole purpose of breathing.

There are several websites that offer information on how to help protect this highly endangered and beautiful tortoise.

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