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.
Giant tortoise
Aldabra giant tortoises reproduce and lay up to 25 rubbery eggs between February and May. Mating is a noisy process, with the males bellowing like a bull, and chasing after the females. During copulation, the male's tail guides his penis into position to fertilize the female, with copulation lasting for 10–15 minutes. Eggs are deposited into a dry, shallow nest on the ground making them particularly vulnerable to being eaten by predators. It is thought that female Aldabra giant tortoises are able to produce more than one clutch a year. The hatchlings emerge after an incubation period of 8 months. The baby Aldabra giant tortoises tend to all emerge during the same two week period which coincides with the arrival of the rainy season. They reach sexual maturity at around the age of 30 years. Although some individuals have been known to live for more than 250 years, their life expectancy is between 80 and 120 years old.