On the ice

Birds and mammals are the main predators in both the Antarctic and the Arctic, but the species that dominate each pole are radically different to each other. Both birds and mammals have found similar ways to deal with the problems that living on the ice brings. The polar region contains some of the most recognisable animals in the world, in the North, the polar bear and in the South, the penguin.

The polar bear, Ursus maritimus, is found though out the pack ice in the Arctic; the majority stay at the thinnest part of the ice as it frequently breaks open (). They are not normally found on the multi-year ice due to its low density of seals, their main prey. They mainly feed on the ringed (Phoca hispida) and bearded seals (Erignathus baratus). They have adapted to life on the ice by evolving a complex layers of fat which provide buoyancy. Their unique fur is only transparent to short range radiation, absorbing it by their black skin. They very commonly overheat after vigorous exercise, as there undercoat is an extremely effective insulator ( Thomas et al.2008).

The emperor penguin (Aptenodyes forestri) can only be seen in the Antarctic. They live entirely on the ice, and feed on a varied diet of fish, squid and krill. It is able to pursue its prey to depths of 50m (PONGANI 2000). It is highly adapted to its environment. As opposed to other species of penguin, the male penguin does not object to being close to others. This modified behaviour allows them in bad weather condition to huddle in flocks as large as 5000 (Thomas et al. 2008). This has been estimated that it can cut down on its loss body weight by up to 50 % each day.

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