Decades ago, India’s tigers were on the brink of extinction. Slowly, their numbers have rebounded. But that ecological success has prompted a dire problem—and a race to save many of them from genetic ...

It was only 6:45 a.m., photographer Joel Sartore noted—and yet his clothes were soaked through to the skin, like “I’d been thrown in a swimming pool.” On this muggy September morning, he was stretched ...