Polar creatures thrive in white world of ice and bitter cold

PUBLISHED : Tuesday, 15 February, 2000, 12:00am
UPDATED : Tuesday, 15 February, 2000, 12:00am

The polar regions cover the Arctic at the North Pole and Antarctica at the South Pole.

The Arctic is isolated from land by ocean whereas the Antarctica is a continent covering more than 13.6 million square kilometres.

The temperature at both poles ranges from 0 degree Celsius to -72 degrees Celsius. This frozen land of icy mountains is the least hospitable place in the world, but amazingly, certain animals and plants thrive there.

Penguins, with their thick waterproof plumage, thick skin, and layer of subcutaneous fat are well suited to life at the South Pole. Their short legs mean that they have little exposed skin, which reduces heat loss.

Penguins are well suited to an extremely cold environment, but they die if the temperature reaches 10 degrees Celsius. Dur ing the breeding season, penguins moult and lose their waterproofing, therefore they must stay on land and remain dry or they will die.

The greatest mammals living in Antarctic waters are the marine mammals - the killer whale and blue whale.

The killer whale is the largest predatory mammal on earth. Their powerful teeth enable them to feast on penguins, seals or other whales.

The blue whale is larger than the killer whale, and can reach 30 metres in length. Despite its size, it feeds on microscopic shrimp- like creatures known as krill.

The Weddell seal is the smartest of the seals and can dive the deepest. It can reach a depth of 600 metres without coming up to take another breath for 73 minutes.

They have large eyes which help them to see in the dark deep ocean below the ice.

They also have protruding front teeth which help them to gnaw holes through the ice for fresh air when they reach the surface. But they have to be wary of polar bears.

The Arctic tern spends its life flying between the North and South poles. They cover huge distances without taking a break and have been been known to fly for over 40,000 kilometres.

Polar bears spend their lives travelling across the ice in search of food. The bears have dense, oily fur, which enables them to hunt in freezing arctic waters.

Polar bears are carnivores and largely feed on seals when they break through the ice for air. The bears creep quietly across the ice, their noses pressed against the surface, and they wait for the seals to come out.

WWF HK is a local charity environmental organisation established in 1981 which aims to build a future in which people can live in harmony with nature. For information, call 2526-1011 or visit the site at http://www.wwf.org.hk