Twenty years ago, this wildlife corridor in southern Kenya was in jeopardy. A scarcity of jobs in this impoverished, arid landscape meant people were hunting wild giraffe and antelope for meat, and chopping down trees to make charcoal. With fewer trees, desertification loomed. Water was so precious that local cattle herders lit fires at water holes to keep giraffes and zebras from drinking.

The animals had less vegetation to eat and less forest cover. Cutting down trees combined with poaching decimated wildlife in this 500,000-acre swath of the Kasigau migration corridor, which bisects Tsavo, Kenya’s largest national park. Tsavo, roughly the size of Wales, is home to half the country’s estimated 25,000 elephants.