Roald, the emperor penguin

Penguins are a group of flightless seabirds that happen to be expert swimmers and divers.

With 19 different species – most of which are found in the southern hemisphere of our planet –, people often find these birds funny, because of how they waddle on land.

Penguins use their wings (fused into one stiff piece) as diving flippers. Their bones are denser than those of other birds, allowing them to float less in water and shielding them from impact on land. Their legs, which they use as a steer while swimming, are set further back on their body than in most birds. However, the position of their legs also makes them clumsier out of water. Their feathers have three layers and grow on a thick layer of fat that isolates them form the cold.

The emperor penguin is the largest penguin species.

They can be over 120 cm tall, weight up to 45 kg and are endemic to Antarctica. Their wings, back and head are black, their belly is white and they have orange and bright yellow ear patches that fade into the white of their breast feathers.

Emperor penguins can hold their breath under water up to 18 minutes, and they can dive as deep as 365 metres. To do so, they accumulate oxygen reserves in their muscles, in the form of myoglobin. They feed mainly on fish, but they also eat small crustaceans and cephalopods.

There is another characteristic that makes these seabirds unique: their reproductive cycle. Every Antarctic winter, they travel 50 to 120 km inland, sliding on their bellies, to gather with a waddle of thousands of emperor penguins. There, each female will lay only one egg that the males will incubate while the females return to the ocean to feed.

During blizzards, penguins huddle for warmth and take turns on the outer part of the colonies, in order to survive the extreme temperatures, which drop as low as -60 ºC. Males incubate the eggs between their legs, until they hatch and the females return with food.