November in Antarctica, and the ice is on the wane. Soon the emperors will go fishing. They'll spend the austral summer gliding through the frigid Southern Ocean, diving to depths of more than 1,500 feet in search of fish, squid and krill to gorge on before making the long trek inland for the winter to breed. When the time comes to haul out, they will launch themselves out of the water back onto the ice. That brief moment between sea and ice is the only time these penguins experience what most birds take for granted: being airborne.
Indeed, emperors and other penguins are bizarre birds. Like all birds, they possess feathers, wings and beaks and lay eggs. But penguins also exhibit a suite of characteristics that readily distinguishes them from their feathered friends. Their wings have evolved into flippers for swimming; their trademark tuxedo camouflages them from predators above and below; their dense bones provide ballast for diving; their short, thick legs steer their body underwater and help give them that endearing (and energetically efficient) waddle on land. Thanks to these traits and others, penguins are masters of the marine realm, and many of their kind—the emperors among them—have managed to conquer one of the most extreme environments on the planet.