Animals of ice and snow
The seas surrounding Antarctica are rich in microscopic animals and plants. This abundant plankton is the basis of a rich and complex marine food chain that includes tiny shimp called krill, many kinds of fish, seabirds such as penguins and skuas, and marine mammals like seals and whales. In summer, 8 different species of whales come to Antarctica to feed.
In summer, the Arctic tundra is home to thousands of migratory ducks and geese that come here to nest and feed. Mammals of the tundra include collared lemming, musk ox and reindeer (caribou). Caribou are the most common large mammal north of the Arctic circle. They roam the tundra feeding on grasses in summer and in winter migrate south to escape the worst of the bitter cold, feeding on lichens that hang from the trees or grow on the ground.
Predators of Arctic lands include Arctic foxes, weasels and brown bears. On the coasts bordering the Arctic Ocean huge polar bears prey on seals.
Seals, whales, walrus and narwhals thrive in the Arctic Ocean.
Keeping out the cold
Fish living in polar regions can function efficiently at temperatures at or below the freezing point, but birds and mammals are warm-blooded animals that must stay warm to survive.
Birds can move further and faster than mammals. Most of them migrate to warmer areas to escape the Arctic winter.