Emperors are the largest of all penguins—an average bird stands some 45 inches (115 centimeters) tall. These flightless animals live on the Antarctic ice and in the frigid surrounding waters.
Penguins employ physiological adaptations and cooperative behaviors in order to deal with an incredibly harsh environment, where wind chills can reach -76°F (-60°C).
They huddle together to escape wind and conserve warmth. Individuals take turns moving to the group's protected and relatively toasty interior. Once a penguin has warmed a bit it will move to the perimeter of the group so that others can enjoy protection from the icy elements.
Emperor penguins spend the long winter on the open ice—and even breed during this harsh season. Females lay a single egg and then promptly leave it behind. They undertake an extended hunting trip that lasts some two months! Depending on the extent of the ice pack, females may need to travel some 50 miles (80 kilometers) just to reach the open ocean, where they will feed on fish, squid, and krill. At sea, emperor penguins can dive to 1,850 feet (565 meters)—deeper than any other bird—and stay under for more than 20 minutes.
Male emperors keep the newly laid eggs warm, but they do not sit on them, as many other birds do. Males stand and protect their eggs from the elements by balancing them on their feet and covering them with feathered skin known as a brood pouch. During this two-month bout of babysitting the males eat nothing and are at the mercy of the Antarctic elements.
When female penguins return to the breeding site, they bring a belly full of food that they regurgitate for the newly hatched chicks. Meanwhile, their duty done, male emperors take to the sea in search of food for themselves.
Mothers care for their young chicks and protect them with the warmth of their own brood pouches. Outside of this warm cocoon, a chick could die in just a few minutes. In December, Antarctic summer, the pack ice begins to break up and open water appears near the breeding site, just as young emperor penguins are ready to swim and fish on their own.