Large Galapagos tortoises can live up to 150 years or more, while a small pet tortoise, such as the red-footed tortoise, can live up to 50 years. Part of the reason why they live so long is their slow metabolism.
The slow metabolism of the Galapagos tortoise contributed to their demise. Part of their appeal as a food source for ships sailing around the islands during the 1800s is the fact that these animals can go a year without food or water. Their slow growth rate also made them vulnerable to predation from introduced pests, such as rats, until they were about five years old.