Aldabra giant tortoise
Large tortoises are among the longest-lived animals. 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 lifespan of 255 years (birth year 1750). Today, Jonathan, a Seychelles giant tortoise ("A. g. hololissa"), is thought to be the oldest living giant tortoise at the age of years and Esmeralda is second at the age of years, since the death of Harriet at 176, a Galapagos giant tortoise. Esmeralda is an Aldabra giant tortoise.
Galápagos tortoise
The remaining species of tortoise range in IUCN classification from extinct in the wild to vulnerable. Slow growth rate, late sexual maturity, and island endemism make the tortoises particularly prone to extinction without help from conservationists. The Galápagos giant tortoise has become a flagship species for conservation efforts throughout the Galápagos.
The Galápagos giant tortoise is now strictly protected and is listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The listing requires that trade in the taxon and its products is subject to strict regulation by ratifying states, and international trade for primarily commercial purposes is prohibited. In 1936, the Ecuadorian government listed the giant tortoise as a protected species. In 1959, it declared all uninhabited areas in the Galápagos to be a national park and established the Charles Darwin Foundation. In 1970, capturing or removing many species from the islands (including tortoises and their eggs) was banned. To halt trade in the tortoises altogether, it became illegal to export the tortoises from Ecuador, captive or wild, continental, or insular in provenance. The banning of their exportation resulted in automatic prohibition of importation to the United States under Public Law 91-135 (1969). A 1971 Ecuadorian decree made it illegal to damage, remove, alter, or disturb any organism, rock, or other natural object in the National Park.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. Its genetic resistance to the negative effects of inbreeding would be another.