Antarctic Animals : Seals

Seals, sea lions and walrus are large marine mammals with four legs that have adapted into flippers. They are pinnipeds, which means 'fin foot'. Their streamlined bodies make them excellent swimmers. All pinnipeds must come ashore to breed, give birth and nurse their young. Some species are at sea for several months at a time while others return to the shore every day. 

There are three families of living pinnipeds:
earless seals (or true seals),
eared seals (or fur seals) and sea lions, and
walrus.

Earless seals do not have flaps over their ears. Their heads look smooth.

The hind, or back, flippers of earless seals face behind them so that they have an awkward movement on land.

Weddell seal pup

Eared seals and sea lions have external (outside) ear flaps, which is how they get their name. Eared seals and sea lions can rotate their hind feet forward and can therefore propel themselves forward with considerable speed.  Unlike the earless seals, they are quite agile on land. The front flippers are used on land to prop themselves up, and in the water to swim with. They use their back flippers rather like a leg on land, and as a rudder in the water.

Fur seal pup

Most mammals, including human beings, shed hair and skin continuously in small quantities, and this is called moulting. The Antarctic seals have one huge moult just once a year. They shed an entire layer of skin with hairs. This is because while they are at sea they dive deep into bitterly cold deep water.  When they do this, blood is kept away from the skin in order to conserve energy and maintain body heat. When the seals come on land to moult, the blood once more circulates to the skin so that a new layer of skin can be grown

Commercial hunting of seals in the 18th and 19th century and in the early years the 20th century played a large role in declining seal numbers. Elephant seals were killed for their blubber, which was boiled down to make oil. Their oil was prized as second only to that of sperm whales. Fur seals were killed for their skins, and many populations were wiped out. Dangers for seals today include drowning after getting entangled in rubbish in the sea and in fishing nets and lines.

Elephant seals
Antarctic fur seals
Leopard seals
Weddell seals
Crabeater seals

Click here to see photos of Antarctic seals

If you use any part of this, acknowledge it in your bibliography like this:
Antarctic Animals (2002). [Online], Available: www.kidcyber.com.au

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updated July 2007