An emperor penguin, or Aptenodytes forsteri, is the largest of the modern species of penguins. Emperor penguins stand about 3.7 feet (1.1 m) tall and weigh 49-99 pounds (22-45 kg). In appearance, the emperor penguin has very dark black feathers on the area of its head, back and tail, with a white belly and wings. Its bill is about 3 inches (8 cm) long, the upper part is black, and the lower part is lilac, pink or orange. Males and females are very similar in color and weight.
Geographically, the emperor penguin is found only in the Antarctic. Its habitat is restricted to the continental shelf, the ice and islands that are between 66 and 78 degrees south latitude. The emperor penguin has developed several methods to keep warm. Its first line of defense is its feathers, which — at 100 feathers per square inch (15 per square cm) — have the highest density of any bird's feathers. Next is a layer of blubber that can be as thick as 1.2 inches (3.0 cm), and last is a layer of down that further insulates the emperor penguin.
Emperor penguins are flightless birds that spend much of their lives in the ocean hunting for food. They are meat eaters whose diet is mainly fish; cephalopods, such as squid; or crustaceans, such as krill. The emperor penguin is able to stay under water for as long as 18 minutes and dive as deep as 700 feet (213 m). This species of penguin has a tongue with barbs that face the rear of its mouth and keep the prey from escaping once caught. They are social birds and frequently coordinate their hunting.
This is the only penguin species whose breeding season is in Antarctica during the winter months from March to December. Breeding season begins in March and April when the adult emperor penguins migrate inland from the edges of the ice pack. Often, the penguins will walk about 30-75 miles (50-120 km) to get to their breeding grounds.
Female emperor penguins lay one egg in May or early June and then leave to feed in the ocean, not returning until the egg has hatched. No nests are built, because the male emperor penguin incubates the egg by holding it on his feet for about two months. After the egg hatches, both parents rotate turns feeding at sea and caring for the chick.