What went right this week: a giant returns, plus more

For the first time in almost 200 years, giant tortoises are roaming the Galapagos island of Floreana again, thanks to one of the most ambitious ecosystem recovery initiatives undertaken on the archipelago.   

Intensive exploitation by whalers and other seafarers, as well as the introduction of invasive species, wiped out the Floreana giant tortoise in the mid-1800s. For more than a century, the lineage was presumed lost forever.

That was until 2000, when ecologists identified a hybrid tortoise with Floreana ancestry on neighbouring Isabela island. The discovery prompted a long-term selective breeding programme to maximise Floreana ancestry in the offspring. 

This week, that programme reached a milestone as 158 giant tortoises were reintroduced to Floreana, which has been cleared of invasive goats and rats. The tortoise’s reintroduction will be mutually beneficial for the species and the island. 

“Giant tortoises are a critical part of this [ecosystem],” said Rakan Zahawi, executive director of the Charles Darwin Foundation, which supported the release. “By dispersing seeds, shaping vegetation, creating microhabitats … and influencing how landscapes regenerate, they help rebuild ecological processes that many other species depend on.” 

Image: Galapagos Conservancy