Just off the coast of Southern California sits Santa Cruz Island, where a magical creature called the island fox dwells. It's a tiny critter—smaller than a house cat—and curious, but also a bit skittish. And it's lucky as hell to be alive.

A decade ago, this island's ecosystem was in chaos. Feral pigs attracted golden eagles from the mainland, and those avian predators crashed the fox population. So the Nature Conservancy, which owns three quarters of the island, launched a full-tilt war against the pigs, complete with helicopters and sharpshooters.

And it worked. Today, the feds are pulling the island fox from the Endangered Species List. It's the fastest-ever recovery of a mammal, joining peers like the Louisiana black bear and the Delmarva Peninsula fox squirrel as glowing mammalian successes in the history of the Endangered Species Act.

But the recovery of Santa Cruz Island isn't just about the fox. The Nature Conservancy has declared war on a slew of invasive species here, from sheep to plants to the aggressive Argentine ant. "Our philosophy with the island has always been, 'OK, remove the threats and let the island go back to what it was,'" says Nature Conservancy ecologist Christina Boser. And it appears to be working. Native plants are coming back, and the fox once again bounds about carefree.

But keeping those foxes from harm will occupy Boser and her conservationist colleagues for years to come. You see, humans are still allowed on Santa Cruz Island, and humans bring dogs. So Boser has to vaccinate her foxes against diseases like distemper and rabies. "We are obligated to keep a pulse on the population for at least five years after the foxes are delisted," says Boser. That includes tagging the foxes and monitoring their numbers to ensure nothing is awry.

This is the story of the little fox that came back from oblivion, and the people who have dedicated their lives to protecting it. This is the story of wildlife conservation in the age of mass extinction.