A controversial approach to ecosystem conservation — replacing extinct species with functionally similar ones from elsewhere — has been successfully demonstrated on a tiny island in the Indian Ocean.

Credit: M. WHITTAKER

The ebony tree (Diospyros egrettarum) was unable to rebound after extensive logging on Ile aux Aigrettes because the giant tortoises and skinks that used to eat its fruit and disperse its seeds had become extinct. So Christine Griffiths at the University of Bristol, UK, and her colleagues introduced 19 adults of the Aldabra giant tortoise (Aldabrachelys gigantea, pictured) from another island between 2000 and 2009. The animals promptly began dispersing ebony seeds. Seeds that had passed through the digestive tracts of tortoises germinated more often and faster than those that had not. Ebony seedlings now dot the island.

Curr. Biol. doi:10.1016/j.cub.2011.03.042 (2011)