A healthy population of giant tortoises has been re-established on one of the Galapagos islands in the Pacific Ocean, after being threatened with extinction.
Goats introduced by sailors as a source of food stripped vegetation from the island of Espanola.
When they were finally eradicated in the 1970s, there were only 15 tortoises left on the island.
But a new survey by scientists shows 1500 tortoises now living there, due to a re-population project.
