Instruct: Given a question, retrieve passages that answer the question.
Query: How old do Galapagos tortoises get?
The Galápagos tortoises are native to seven of the Galápagos Islands, a volcanic archipelago about 1,000km (620mi) west of the Ecuadorian mainland. With lifespans in the wild of over 100 years, it is one of the longest-lived vertebrates. A captive individual lived at least 170years. Spanish explorers, who discovered the islands in the 16th century, named them after the Spanish galápago, meaning "tortoise".[11]
Giant tortoises are characteristic reptiles that are currently found on two groups of tropical islands: the Aldabra Atoll and Fregate Island in Seychelles and the Galapagos Islands in Ecuador (a population at the Mascarene Islands was exterminated by the 1900s). These tortoises can weigh as much as and can grow to be long. Giant tortoises originally made their way to islands from the mainland; for example, the Aldabra Atoll and Mascarenes giant tortoises are related to Madagascar tortoises while the Galapagos giant tortoises are related to Ecuador mainland tortoises. This phenomenon of excessive growth is known as island gigantism or insular gigantism. It occurs when the size of the animals that are isolated on an island increases dramatically in comparison to their mainland relatives. This is due to several factors such as relaxed predation pressure, competitive release, or as an adaptation to increased environmental fluctuations on islands. However, giant tortoises are no longer considered to have been examples of island gigantism, as they originally evolved their massive sizes on the mainland. Giant tortoises were once common across the Cenozoic faunas of Eurasia, Africa and the Americas.
Giant tortoises are among the longest-lived animals on the planet. Some individual Aldabra giant tortoises are thought to be over 200 years of age, but this is difficult to verify because they tend to outlive their human observers. Adwaita was reputedly one of four brought by British seamen from the Seychelles Islands as gifts to Robert Clive of the British East India Company in the 18th century, and came to Calcutta Zoo in 1875. At his death in March 2006 at the Kolkata (formerly Calcutta) Zoo in India, Adwaita is reputed to have reached the longest ever measured life span of 255 years (birth year 1750). Today, Jonathan, a -year-old, Saint Helena-dwelling Seychelles giant tortoise, is thought to be the oldest living terrestrial animal on Earth since the 2006 death of Harriet; a 176 year old Galapagos giant tortoise who lived at Australia Zoo. Coming in second to Jonathan is Esmeralda, at years old. Esmeralda is an Aldabra giant tortoise that lives in the Galapagos Islands.
The Pinta Island tortoise ("Geochelone nigra abingdoni") had only one living individual, named Lonesome George, until his death in June 2012. The tortoise was believed to be entirely extinct in the mid-20th century, until Hungarian malacologist József Vágvölgyi spotted Lonesome George on the Galapagos island of Pinta on 1 December 1971. Since then, Lonesome George has been a powerful symbol for conservation efforts in general and for the Galapagos Islands in particular. With his death on 24 June 2012, the subspecies is again believed to be extinct. With the discovery of 17 hybrid Pinta tortoises located at nearby Wolf Volcano a plan has been made to attempt to breed the subspecies back into a pure state.
As is common in the Galapagos, Wolf Volcano has unique fauna, differing from not only the other islands in the group but also its neighbouring volcanoes on the same island. It has its own subspecies of Galapagos tortoise, "Chelonoidis nigra becki" which has a saddleback shell and is found on the northern and western slopes of the volcano, away from the more recent lava flows where there is denser vegetation. However, tortoise subspecies from many different Galapagos islands have been abandoned at Wolf Volcano by ships which at one time collected the tortoise as a food source. "C. n. becki" is threatened due to population pressures such as predation by feral cats. During a 2008 survey of over 1600 specimens on Wolf Volcano, all morphologies of tortoise were found, including two that in shape are similar to Lonesome George. DNA studies of these specimens are currently being undertaken.
"Phoenix" was in the Galapagos in 1835 and 1836. On 10 January 1836 the crew was ashore and left graffiti carved into rocks there. While in the Galapagos islands the crew also gathered tortoises to eat, perhaps as many as 140.
In 1793, James Colnett, (1753 – 1 September 1806) was an officer of the British Royal Navy, an explorer, and a maritime fur trade described the flora and fauna of the islands and suggested they could be used as base for the whalers operating in the Pacific Ocean. Collnet also drew the first charts of the Galapagos. These whalers captured and killed thousands of tortoises in the archipelago because the tortoises could survive for months without food or drink. The gigantic Galapagos tortoises were transported inside the holds of whailing ships. A phrase "living cupboards" could be desortugas would be kept alive and killed when fresh meat was required by the whailing crews. Tortoises provided fresh protein on the long journeys typical of whaling ships. Hunting of these tortoises was the cause of the large decrease of their population, and in some cases the destruction of certain species of the Galapagos Tortoise.
Chelonoidis elephantopus, an extinct tortoise, originally discovered on the Galapagos Islands by Charles Darwin, has hopes of being revived through selective breeding. A group of scientists have collected over 1,700 blood samples from tortoises on Isabela Island during an expedition in 2012 having identified 80 tortoises with traces of the extinct species DNA.[16]
Turtle "Shetyw", "Shetw", "Sheta", "shtyw" was common in Ancient Egyptian Art (especially Predynastic and Old Kingdom art). Turtle fossils are the most common reptiles found in the Fayoum, including "Gigantochersina ammon", a tortoise as large as those living on the Galapagos Islands today. Charles Andrews was the first to write in the West about these tortoises in the early 20th century.
In the Galapagos Islands, Ecuador, EPI students work to rehabilitate the threatened giant Galapagos land tortoise in partnership with the Galapagos National Park. Youth support biodiversity protection by helping researchers monitor wild tortoises, protect nests, care for juveniles, eradicate invasive species, and restore habitat.
On the southern island of Española, only 14 adult tortoises were found, two males and 12 females. The tortoises apparently were not encountering one another, so no reproduction was occurring. Between 1963 and 1974, all 14 adult tortoises discovered on the island were brought to the tortoise center on Santa Cruz and a tortoise breeding program was initiated. In 1977, a third Española male tortoise was returned to Galapagos from the San Diego Zoo and joined the breeding group.[73] After 40 years' work reintroducing captive animals, a detailed study of the island's ecosystem has confirmed it has a stable, breeding population. Where once 15 were known, now more than 1,000 giant tortoises inhabit the island of Española. One research team has found that more than half the tortoises released since the first reintroductions are still alive, and they are breeding well enough for the population to progress onward, unaided.[74]
Darwin later compared the different tortoise forms with those of mockingbirds, in the first[115] tentative statement linking his observations from the Galapagos with the possibility of species transmuting:
The Galapagos Tortoise Movement Ecology Programme is a collaborative project coordinated by Dr Stephen Blake of the Max Planck Institute for Ornithology. Its goal is to assist the Galapagos National Park to effectively conserve giant tortoises by conducting cutting-edge applied science, and developing an inspirational tortoise-based outreach and education programme. Since 2009, the project team have been analysing the movements of giant tortoises by tracking them via satellite tags. As of November 2014, the team have tagged 83 tortoises from four species on three islands. They have established that giant tortoises conduct migrations up and down volcanoes, primarily in response to seasonal changes in the availability and quality of vegetation.[148] In 2015 they will start to track the movements of hatchling and juvenile tortoises, supported by the UK's Galapagos Conservation Trust.[149]
The Réunion giant tortoise was 50 to 110 cm long. It was the largest of the "Cylindraspis" giant tortoise species of the Mascarenes. It was roughly the same size as modern Aldabra and Galapagos tortoises, though it was a longer and more elongated animal.
The closest living relative of the Galapagos giant tortoise is the small Chaco tortoise from South America, although it is not a direct ancestor. Scientists believe the first tortoises arrived to Galapagos 2–3 million years ago by drifting 600 miles from the South American coast on vegetation rafts or on their own. They were already large animals before arriving in Galapagos. Colonizing the eastern-most islands of Española and San Cristóbal first, they then dispersed throughout the archipelago, eventually establishing about 16 separate populations on ten of the largest Galapagos Islands. Currently there are only 10 species of Galapagos Giant Tortoises left of the original 16 species. 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." The tortoises also conveniently held water in their neck that could be used as drinking water.
They weathered a typhoon off the Cocos (Keeling) Islands, touched in at Rodrigues and Mauritius and changed course to round the tip of South Africa (Durban, Cape Town) rather than go through the Mediterranean during the Suez crisis; Brazil (Fortaleza); the east coast of the United States from New York, then south to the West Indies. They went through the Panama Canal to the Galapagos Islands, where they traded six packages of instant powdered milk, one can of shortening and two bottles of hot pepper sauce for a Galapagos tortoise, 11x11 inches across the shell, naming him Jonathan Mushmouth. (They had a legal permit issued in Ecuador, to take "two of every kind" of animal from the islands.) Years later they gave Jonathan to the Hanshin Zoo in Osaka, Japan, the zoo's first Galapagos tortoise. The Reynolds family expected Jonathan to outlive them but he died in the 1980s.
Yellow-footed tortoises are a large species – fifth-largest overall and third-largest mainland species, after the Aldabra giant tortoise ("Aldabrachelys gigantea"), Galapagos giant tortoise ("Chelonoidis nigra"), African spurred tortoise, and Asian forest tortoise. Typical sizes average 40 cm (15.75 in), but much larger specimens are common. The largest know specimen is a female that was 94 cm (37 in) long. They closely resemble the red-footed tortoise, and can sometimes be difficult to tell apart, especially as a preserved specimen, which led to quite a bit of confusion over the names and ranges.
In a 2003 study of the subspecies of Galapagos tortoise on Alcedo, "Geochelone nigra vandenburghi" the genetic diversity was shown to be much lower than would be expected in a population of its size, currently estimated to be approximately 4000. The Alcedo tortoise has the largest wild populations in the Galapagos Islands, however, the genetic diversity was 3-5 times less than that of other sub species of Galapagos tortoise. This low diversity is believed to be caused by a massive reduction in the population approximately 100,000 years ago. The reduction in population to only a few individuals is believed to have been caused by a large eruption of Alcedo volcano. The Alcedo tortoise has managed to rebuild its population since that time. Since the islands discovery by man it has come under new pressure, as have other Galapagos tortoises. They were hunted by early sailors to the islands as tortoises provided a food source on subsequent voyages. The introduction of non-native species also affected the habitat of the tortoise and other fauna and flora on Alcedo.
Feral goats were introduced by humans to the islands for agricultural reasons have had a huge impact on the ecosystem. Feral goats are dangerous to the environment because they eat everything in sight, destroying many habitats. These goats do not have natural predators, thus their population continues to grow which leads to a decrease in other organisms they prey on. The goats have had a huge impact on a specific species on the island, the Galapagos tortoise. The goats would eat all of the food and resources needed by the tortoises, eventually driving the tortoises towards extinction.
With an average length of 40 cm (15.75 in) and the largest known specimen at 94 cm (37 in), this is the sixth-largest tortoise species on Earth, after the Galapagos tortoise, the Aldabra tortoise, the African spurred tortoise ("Geochelone sulcata", typical size 76 cm (30 in)), the leopard tortoise ("Stigmochelys pardalis"), and the Asian forest tortoise ("Manouria emys emys", typical size 60 cm (23.6 in)).
"C. sulcata" is the third-largest species of tortoise in the world after the Galapagos tortoise, and Aldabra giant tortoise, and the largest of the mainland tortoises. Adults can reach and can weigh . They grow from hatchling size (2–3 in) very quickly, reaching 6-10 in (15–25 cm) within the first few years of their lives. They can live more than 70 years.
With the establishment of the Galapagos National Park and the CDF in 1959, a review of the status of the tortoise populations began. Only 11 of the 14 original populations remained and most of these were endangered if not already on the brink of extinction. The breeding and rearing program for giant tortoises began in response to the condition of the population on Pinzón, where fewer than 200 old adults were found. All of the hatchlings had been killed by introduced black rats, for perhaps more than a century. Without help, this population would eventually disappear. The only thing preserving it was the longevity of the tortoise.[138] Its genetic resistance to the negative effects of inbreeding would be another.[133]
Introduced mammals Poachers Destruction of habitat Characteristics that make tortoises vulnerable Slow growth rate Late sexual maturity Can only be found on Galapagos Islands Large size and slow moving[132]
The small Natural History Museum (Museo de Ciencias Naturales) has a statue of Charles Darwin at the entrance. It is located in the heart of the town to the east of the Parque la Carolina, next to the Franciscan mission. It contains exhibits of many animals, plants and minerals of the Galápagos. Of note is a giant tortoise, which is said to be more than 80 years old; an exhibit of a predecessor species of iguana; the flightless cormorant; and the Galapagos tortoise – three drawings for each of these fauna are on display.
Outside of the livestock industry, hot branding was used in 2003 by tortoise researchers to provide a permanent means of unique identification of individual Galapagos tortoises being studied. In this case, the brand was applied to the rear of the tortoises' shells. This technique has since been superseded by implanted PIT microchips (combined with ID numbers painted on the shell).