WARNING: This page contains graphic content. When rescuers slowly creaked the rusty door open, the dilapidated building appeared to be empty. Windowless and dark, the sheet-metal structure held no noise, only air thick with spiderwebs, dust and the burning smell of ammonia. Then a head with small...

You’d think it would be easy to persuade people to protect prairie dogs: Not only are they a keystone species, with nine other species directly dependent on them for survival, but they’re also irresistibly cute, with big eyes and big personalities. Yet the personable little rodents often find...

Flying back and forth over Cape Cod Bay, a survey plane spotted a half dozen of the world’s rarest creatures: North Atlantic right whales. Such sightings are good news. The species hovers near extinction—by one estimate, fewer than 360 remain. Each time researchers locate a whale, they take pictures...