Europeans ate their way through the island nation of Mauritius, most famously eliminating the dodo bird. Less well known was their effect on the island now known as Ile aux Aigrettes or Island of White Herons, where they exterminated giant skinks and tortoises, and logged the native ebony trees for firewood.
In 1965 the largely denuded 25 hectares of the island were declared a nature preserve. But even in the absence of logging, the slow-growing ebony forests failed to thrive. Why? Because they had lost the animals that ate their fruit and dispersed their seeds.
Scientists have now rectified that situation, although you might call it a slow fix. Because tortoises are the key.
Researchers relocated four giant Aldabra tortoises to Ile aux Aigrettes in 2000.The tortoises ate the ebony trees’ large, pungent oval fruits and dispersed the seeds. By 2009, a total of 19 introduced tortoises roamed the island—leaving behind more than 500 dense patches of ebony seedlings. The project is described in the journal Current Biology.
For this tiny island, at least, re-wilding appears to have worked. And that holds out hope for other restoration ecology projects in the midst of the sixth mass extinction in Earth's history.