The number of giant tortoises on Espanola, one of the Galapagos Islands, has been on a steady rise since the 1960s, when they were facing extinction. There were once only 15 of the animals, which can weigh up to 500 pounds and live to be 100 years old, but after 40 years' work reintroducing captive animals to the island, they now number in the 1000s. Read more: bbc.com