An island fox kit emerges from its underground den and sniffs the brush on Santa Cruz Island, some 20 miles off the southern coast of California. His brother follows, and the two foxes tumble over each other as they play fight. Soon their mother halts the fun, grooms both pups from head to tail, then leads them away to teach them how to hunt.
A few decades ago, about 4,000 island foxes roamed Santa Cruz Island and two others in the Channel Islands National Park. But recently they nearly disappeared. Human activity had dangerously altered the foxes’ habitat, and by 1999 only about a hundred foxes remained.
Scientists knew that if they wanted to save this fox—a species that lives nowhere else on Earth—they’d have to change the islands again.…