 Sexual maturity is reached at around 20–25 years in captivity, possibly 40 years in the wild.Life expectancy in the wild is thought to be over 100 years, making it one of the longest-lived species in the animal kingdom.Harriet, a specimen kept in Australia Zoo, was the oldest known Galápagos tortoise, having reached an estimated age of more than 170 years before her death in 2006.