Penguins

Penguins are aquatic flightless birds.

There are 17 recognised species of penguin.

Not all species of penguin live near Antarctica, although they all do live in the Southern Hemisphere. But they are the most common bird on Antarctica, living in huge colonies.

The Tuxedo Bird

All penguins have a very distinctive colouring, dark on the back and white on the front. This two tone colouring is called countershading. Its a type of camouflage. When seen from above, they blend in with the dark ocean, and if a predator sees them from below, their white bellies blend in with the white reflections from the sun.

All penguins have a similar body shape, but they vary greatly in size. The largest living species of penguin in the Emperor Penguin which can weigh in at over 35kg, and stands over a meter high. The little blue penguin (also known as a fairy penguin) is the smallest penguin. It only grows to be 40cm tall and weighs 1kg.

Flying....underwater

Pygoscelis papua -Nagasaki Penguin Aquarium
by Ken FUNAKOSHI 

Penguins are flightless birds, but are excellent swimmers. Some species spend 75% of their time at sea. In fact, and penguin swimming looks just like a bird flying in the air. Within its smooth plumage, a layer of air is kept to help with buoyancy. Their legs and tail form an underwater rudder, streamlining the bird which helps them get up to their 10kph cruising speed. Whilst swimming, they will jump out of the water every few meters to breath and conserve energy.
The are excellent divers. There have been recorded incidents of penguins diving to 250m, and a female emperor penguin dived an amazing 535m. Unlike flying birds, penguins have dense bones which help them with diving.

Even on land, penguins can move great distances. Either by waddling around, or tobogganing on their bellies. They have a lot of power in their legs, and can jump great heights compared to their size.

Home freezing home.

"Colony of aptenodytes patagonicus"
by Pismire

Penguins live well in the cold. Their short feathers overlap and form a thick waterproof layer. These feathers are kept oiled by a special gland at the base of the tail. Underneath these feathers are smaller, fluffier feathers which trap warm air and provide a layer of insulation. Then just under the skin, they have a layer of fat which helps keep them warm and helps if there isn't much around to eat.
Penguins are so good at keeping warm that they can over heat in the summer!

But the feathers wear out, and need replacing every year. The penguin will spend time fattening up, trying to put on over half its own body weight before coming ashore to moult. When they are moulting, they cant swim because they are no longer water proof.

Penguins live in huge colonies called Rockeries. There can be as many as a million nesting pairs. Scientists estimate that there are 20 million breeding pairs of penguin on Antarctica. They all love in these rockeries which are close to the coast line. They make their home on exposed rock, and that's where they breed (except Emperor penguins who breed on sea ice)
Having baby chicks at the right time. The chicks need to have grown up in time before the first winter storms hit and Antarctica is plunged into constant darkness. Most penguins lay two eggs, and incubation is shared by the parents. Once the chick has hatched, they are looked after in creche's while the parents go out to find more food to feed the chick.

Whats for dinner?

Penguins live on fish, squid and crustaceans. Smaller penguins feed on small shrimp like krill that form dense swarms. Penguins adapt to what ever food source is available, and their diet often varies through the year.
Penguins can drink sea water. They have a special gland that filters out excess salt from their blood stream. Its called a supraorbital gland. Penguins do not physically drink sea water, but all their water needs are met by the prey they ingest.