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© WWF / Fritz PÖLKING
Penguins are a group of flightless seabirds found in the Southern Hemisphere. The greatest number is found on the coasts of Antarctica and on the subantarctic islands. Some penguin species live as far north as the Galapagos Islands on the Equator and the subtropical coasts of South America, South Africa and Australia.
But even in warm areas, they live only where cold water currents exist, such as the Humboldt Current along the western coast of South America and Benguela and Agulhas Currents around South Africa. Of the 17 species of penguins, the largest, such as the Emperor and Adelie penguins, are found in the Antarctic.
Penguins have flippers instead of wings and therefore cannot fly. Though they are feathered they spend most of their lives at sea and must return to land to mate and lay eggs. On land, they either waddle on their feet or slide on their bellies.
Having evolved streamlined bodies, they can swim at up to 25 kms per hour (15mph). And they are not just superb swimmers, but also world class divers!
The reason for the penguins' distinctive markings is something that is quite common to most creatures who "operate" in the sea. The white underside and a dark upper-side is camouflage against predators (think of leopard seal looking up against the light of the sky, versus one looking down at the murkier depths...).
On land, penguins are less agile. They almost always stand upright, using the stout tail feathers as a prop. They waddle rather than walk because of their short legs, but on ice they can move fast, even tobogganing on their bellies.
Penguins feed on small fish, floating crabs and squids. Most species of penguins eat snow, and all of them drink salt water and fresh water. They can endure long periods without food on land.
Penguins are very social animals, breeding in groups or in large noisy colonies called rookeries. They mate on shore in spring - almost always with the same partner. Penguins lay 1 or 2 eggs, though usually only 1 chick is reared.
Nests in polar regions range from a simple hollow in the ground to an elaborate structure of pebbles, bones and sticks. Chinstrap penguins sometimes nests in snow which melts, leaving the bird in a water-filled hole. The King Penguin does not build a nest at all. In temperate zones, penguins nest in scattered grasses, bushland or holes in sandunes.
After laying her egg, a mother Emperor Penguin returns to the sea to feed and the father incubates the egg on his feet for as long as 60 days till the egg hatches! Usually, the mother returns to care for the chick about the time it hatches, but if she is still away at sea, the father penguin feeds the baby chick with a milky fluid from his throat.
The baby is covered with a sparse downy coat and is carefully brooded till it is 6 to 10 days old. After this, they begin to regulate their own temperature, but often chicks are herded together in tight groups to keep warm.
Penguins moult (shed their old feathers) soon after the young have become independent. Polar penguins change the entire plumage at once in a so-called 'catastrophic moult' with new feathers pushing the old ones out of the skin. Later, the old layer falls out in whole patches.
Pretty good - depending on which species you want to see (it's harder of course to get to see the famous Emperor penguin simply because of its geographic isolation in Antarctica).
Today, penguins face a number of threats, including destruction of nesting habitats, competition with fishermen for fish and shrimp, and introduced predators such as rats, dogs and foxes which eat penguin eggs and young.
However, the greatest potential threat to penguins in global warming, as they are extremely sensitive to climate change.