Reteti Elephant Sanctuary, KenyaFrom afar, the cries of a baby elephant in distress seem almost human. Drawn by the sounds, young Samburu warriors, long spears in hand, thread their way toward a wide riverbed, where they find the victim. The calf is half-submerged in sand and water, trapped in one of the hand-dug wells that dot the valley. Only its narrow back can be seen—and its trunk, waving back and forth like a cobra.

As recently as a year ago, the men likely would have dragged the elephant out before it could pollute the water and would have left it to die. But this day they do something different: Using a cell phone, ubiquitous even in remotest Kenya, they send a message to Reteti