Giant tortoise
Encyclopedia
Giant tortoises are characteristic reptiles of certain tropical islands. Often reaching enormous size—they can weigh as much as 300 kg (660 lbs) and can grow to be 1.3 m (4 ft) long—they live, or lived (some species
are recently extinct), in the Seychelles
, the Mascarenes and the Galapagos. Today, the world's largest population inhabits Aldabra Atoll
in Seychelles, where there are approximately 150,000 individuals. Although appearing similar, the tortoises represent separate branches of evolution. The Seychelles and Mascarenes tortoises derive from nearby Madagascar, while the Galapagos tortoises came from nearby Ecuador.
Prior to the arrival of Homo sapiens, giant tortoises occurred in non-island locales as well. Between 200,000 to 10,000 years ago, tortoises on the mainland of Asia, in Indonesia
, in Madagascar
, in North and South America, and even the island of Malta
became extinct.
These animal
s belong to an ancient group of reptile
s, appearing about 250 million years ago. In the Upper Cretaceous, 70 or 80 million years ago some already became gigantic. About 1 million years ago tortoises reached the Galápagos Islands. Since 100,000 years ago most of the gigantic species began to disappear. Only 250 years ago there were at least 20 species and subspecies in islands of the Indian Ocean
and 14 or 15 subspecies in the Galápagos Islands.
During the 16th and 17th centuries, the Galápagos were frequented by buccaneers preying on Spanish treasure ships. Filling a ship's hold with tortoises was an easy way to stock up on food, a tradition that was continued by whalers in the centuries that followed: "'whaling skippers were almost lyrical in their praise of tortoise meat, terming it far more delicious than chicken, pork or beef'. They said the meat of the giant tortoise was 'succulent meat and the oil from their bodies as pure as butter, but best of all, the giants could hibernate in a ship’s damp for a year or more.'"
Today, only one of the species of the Indian Ocean survives in the wild, the Aldabra giant tortoise
(two more are claimed to exist in captive or re-released populations, but some genetic studies have cast doubt on the validity of these as separate species) and 11 subspecies in the Galápagos.
Giant tortoises are among the world's longest-living animals, with an average lifespan of 100 years or more. The Madagascar
radiated tortoise
Tu'i Malila
was 188 at death in Tonga
in 1965. Harriet (initially thought to be one of the three Galápagos tortoise
s brought back to England from Charles Darwin
's Beagle voyage but later shown to be from an island not even visited by Darwin) was reported by the Australia Zoo
to be 176 years old when she died in 2006. Also, on 23 March 2006, an Aldabra giant tortoise
named Adwaita
died at Alipore Zoological Gardens
in Kolkata
. He was brought to the zoo in the 1870s from the estate of Lord Robert Clive
and is thought to have been around 255 years old when he died. Around the time of its discovery, they were caught and killed for food in such large quantities that they became virtually extinct by 1900. The giant tortoise is now under strict conservation laws and is categorised as an endangered species.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are recently extinct), in the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, the Mascarenes and the Galapagos. Today, the world's largest population inhabits Aldabra Atoll
Aldabra
Aldabra, the world's second largest coral atoll, is in the Aldabra Group of islands in the Indian Ocean that form part of the Seychelles. Uninhabited and extremely isolated, Aldabra is virtually untouched by humans, has distinctive island fauna including the Aldabra Giant Tortoise, and is...
in Seychelles, where there are approximately 150,000 individuals. Although appearing similar, the tortoises represent separate branches of evolution. The Seychelles and Mascarenes tortoises derive from nearby Madagascar, while the Galapagos tortoises came from nearby Ecuador.
Prior to the arrival of Homo sapiens, giant tortoises occurred in non-island locales as well. Between 200,000 to 10,000 years ago, tortoises on the mainland of Asia, in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, in Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, in North and South America, and even the island of Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
became extinct.
These animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s belong to an ancient group of reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, appearing about 250 million years ago. In the Upper Cretaceous, 70 or 80 million years ago some already became gigantic. About 1 million years ago tortoises reached the Galápagos Islands. Since 100,000 years ago most of the gigantic species began to disappear. Only 250 years ago there were at least 20 species and subspecies in islands of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and 14 or 15 subspecies in the Galápagos Islands.
During the 16th and 17th centuries, the Galápagos were frequented by buccaneers preying on Spanish treasure ships. Filling a ship's hold with tortoises was an easy way to stock up on food, a tradition that was continued by whalers in the centuries that followed: "'whaling skippers were almost lyrical in their praise of tortoise meat, terming it far more delicious than chicken, pork or beef'. They said the meat of the giant tortoise was 'succulent meat and the oil from their bodies as pure as butter, but best of all, the giants could hibernate in a ship’s damp for a year or more.'"
Today, only one of the species of the Indian Ocean survives in the wild, the Aldabra giant tortoise
Aldabra Giant Tortoise
The Aldabra giant tortoise , from the islands of the Aldabra Atoll in the Seychelles, is one of the largest tortoises in the world....
(two more are claimed to exist in captive or re-released populations, but some genetic studies have cast doubt on the validity of these as separate species) and 11 subspecies in the Galápagos.
Giant tortoises are among the world's longest-living animals, with an average lifespan of 100 years or more. The Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
radiated tortoise
Radiated Tortoise
The radiated tortoise is a species in the family Testudinidae. Although this species is native to and most abundant in southern Madagascar, it can be also be found in the rest of this island, and has been introduced to the islands of Réunion and Mauritius...
Tu'i Malila
Tu'i Malila
right|thumb|200px||A photo of the tortoise's preserved body, 2003.Tu'i Malila was a tortoise given to the royal family of Tonga by Captain James Cook. It was a radiated tortoise from Madagascar and is the second longest-lived tortoise whose age has been verified.The name means King Malila in the...
was 188 at death in Tonga
Tonga
Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...
in 1965. Harriet (initially thought to be one of the three Galápagos tortoise
Galápagos tortoise
The Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
s brought back to England from Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
's Beagle voyage but later shown to be from an island not even visited by Darwin) was reported by the Australia Zoo
Australia Zoo
Australia Zoo is a zoo located in the Australian state of Queensland on the Sunshine Coast near Beerwah/Glass House Mountains. It is a member of the Zoo and Aquarium Association , and is owned by Terri Irwin, the widow of Steve Irwin, whose wildlife documentary series The Crocodile Hunter made the...
to be 176 years old when she died in 2006. Also, on 23 March 2006, an Aldabra giant tortoise
Aldabra Giant Tortoise
The Aldabra giant tortoise , from the islands of the Aldabra Atoll in the Seychelles, is one of the largest tortoises in the world....
named Adwaita
Adwaita
Adwaita was the name of a male Aldabra giant tortoise in the Alipore Zoological Gardens of Kolkata, India...
died at Alipore Zoological Gardens
Alipore Zoological Gardens
The Alipore Zoological Gardens is India's oldest formally stated zoological park and a big tourist attraction in Kolkata, West Bengal. It has been open as a zoo since 1876, and covers...
in Kolkata
Kolkata
Kolkata , formerly known as Calcutta, is the capital of the Indian state of West Bengal. Located on the east bank of the Hooghly River, it was the commercial capital of East India...
. He was brought to the zoo in the 1870s from the estate of Lord Robert Clive
Robert Clive, 1st Baron Clive
Major-General Robert Clive, 1st Baron Clive, KB , also known as Clive of India, was a British officer who established the military and political supremacy of the East India Company in Bengal. He is credited with securing India, and the wealth that followed, for the British crown...
and is thought to have been around 255 years old when he died. Around the time of its discovery, they were caught and killed for food in such large quantities that they became virtually extinct by 1900. The giant tortoise is now under strict conservation laws and is categorised as an endangered species.
Species and subspecies
- Cylindraspis indica—Réunion giant tortoise (extinct)
- Cylindraspis inepta—Saddle-backed Mauritius giant tortoise (extinct)
- Cylindraspis peltastes—Domed Rodrigues giant tortoise (extinct)
- Cylindraspis triserrata—Domed Mauritius giant tortoise (extinct)
- Cylindraspis vosmaeri—Saddle-backed Rodrigues giant tortoise (extinct)
- Dipsochelys hololissa—Seychelles giant tortoiseSeychelles giant tortoiseThe Seychelles giant tortoise has been thought to be extinct since the mid-19th century due to overexploitation on the granitic Seychelles islands. Similar giant tortoise species on other Indian Ocean islands such as Mauritius, Réunion and Rodrigues Island are also extinct...
(extinct in the wild) - Dipsochelys arnoldi—Arnold's giant tortoiseArnold's Giant TortoiseArnold's giant tortoise , also known as the Seychelles saddle-backed tortoise, inhabited the granitic Seychelles islands until around 1840, when it was presumed to be extinct, along with the Seychelles giant tortoise; a species which shared the same islands.The report of oddly-shaped of tortoises...
(extinct in the wild) - Aldabrachelys gigantea/Dipspchelys dussumieri—Aldabra giant tortoiseAldabra Giant TortoiseThe Aldabra giant tortoise , from the islands of the Aldabra Atoll in the Seychelles, is one of the largest tortoises in the world....
- Chelonoidis nigra—Galápagos tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra abingdoni—Abingdon Island tortoiseLonesome GeorgeLonesome George is a tortoise, the last known individual of the Pinta Island tortoise , which is one of eight to fifteen extant subspecies of Galápagos tortoise, all of which are native to the Galápagos Islands...
(extinct in the wildExtinctionIn biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
) - Chelonoidis nigra becki—Volcan Wolf tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra chathamensis—Chatham Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra darwini—James Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra ephippium—Duncan Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
(extinct in the wild) - Chelonoidis nigra galapagoensis—Charles Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra guntheri—Sierra Negra tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra hoodensis—Hood Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra microphyes—Volcan Darwin tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra porteri—Indefatigable Island tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra vandenburghi—Volcan Alcedo tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra vaicina—Iguana Cove tortoiseGalápagos tortoiseThe Galápagos tortoise or Galápagos giant tortoise is the largest living species of tortoise, reaching weights of over and lengths of over . With life spans in the wild of over 100 years, it is one of the longest-lived vertebrates...
- Chelonoidis nigra abingdoni—Abingdon Island tortoise
- Meiolania platycepsMeiolaniaMeiolania is an extinct genus of cryptodire turtle from the Oligocene to Holocene, with the last relict populations at New Caledonia which survived until 2,000 years ago....
(extinct)