This article was originally published in Hakai Magazine. By the late 19th century, whalers, settlers, and pirates had changed the ecology of the Galápagos Islands by poaching some native species—like Galápagos giant tortoises—and introducing others, such as goats and rats. The latter species became pests and severely destabilized the island ecosystems. Goats overgrazed the plants the tortoises ate while rats preyed on their eggs. Over time, the tortoise population plummeted. On Española, an island in the southeast of the archipelago, the tortoise count fell from thousands to less than 20. Along the way, as goats ate all the plants they could, Española—once akin to a savanna—turned barren. In the following century, conservationists set out to restore the Galápagos giant tortoise on Española—and the island ecosystem. They began eradicating the introduced species, and capturing Española’s remaining tortoises and breeding them in captivity. With the goats wiped out and the tortoises in cages, the ecosystem transformed once again. This time, the overgrazed terrain became overgrown with densely packed trees and woody bushes. Española’s full recovery to its …