The black rhino is nature's tank, feared by all animals. Even lions will break off a hunt to detour around one. And yet the black rhino is on the edge of extinction, its numbers dwindling from 100,000 at the turn of the century, to less than 2,500 today. The reason is that in places like Yemen, China, Korea, Taiwan, and Thailand, the rhino's horn is more valuable than gold, so valuable that people will risk their lives to harvest it. To deter rhino poachers, African governments have spent millions--on helicopters, paramilitary operations, fences and guard dogs, even relocation to protected...

The black rhino is nature's tank, feared by all animals. Even lions will break off a hunt to detour around one. And yet the black rhino is on the edge of extinction, its numbers dwindling from 100,000 at the turn of the century, to less than 2,500 today. The reason is that in places like Yemen, China, Korea, Taiwan, and Thailand, the rhino's horn is more valuable than gold, so valuable that people will risk their lives to harvest it. To deter rhino poachers, African governments have spent millions--on helicopters, paramilitary operations, fences and guard dogs, even relocation to protected...