The land mass surrounding the South pole, the Antarctic, is the coldest place in the world! The temperature has been known to fall as low as –83.3°C. Like all Antarctic penguins, the largest of them all, the emperor penguin, has a thick layer of densely packed feathers (about 12 to the square centimetre), and tufts of down at the base of each feather which act like a thermal vest, trapping air to keep the bird warm. The tips of the outer feathers are broad and curved, overlapping like roof riles – this makes the bird waterproof. A thick layer of blubber (fat) also helps to keep the penguin warm when swimming in the icy ocean. To help it adapt even more to the intense cold of its habitat, this penguin has special nasal passages so that it loses very little heat when breathing out. Its flippers and legs are also specially adapted to reduce heat loss.
Winter in the Antarctic begins in March and whereas other animals sensibly make their way to the warmer parts of north Antarctic, the colonies of emperor penguins march across the pack-ice about 200 miles in the opposite direction, to breed in the coldest place on Earth! The breeding sites, called ‘rookeries’, may be many miles from the sea and number up to 25,000 birds. The parents do not make a nest. To begin with they both take it in turns to protect the egg from the ice by resting it on their feet, raising their toes to keep it well off the ground. The female then returns to the sea to feed, leaving the male to incubate the egg for nearly three months. He uses a fold of skin, which hangs over the egg, to keep it warm. The male eats nothing, relying on his reserves of blubber to keep him alive. Hundreds of incubating males may huddle together for warmth. They will have lost almost half of their original body weight by the time the egg hatches.
The female returns to the rookery when the chick is ready to hatch and takes over the brooding of the down-covered baby, feeding it with regurgitated food. The hungry, exhausted male trudges back to sea to feed.
As many as 6,000 emperor penguins may huddle together to form a ‘tortoise’. They take it in turns to move into the middle where it is warm.