The polar caps have the most extreme seasonal contrasts, growing and melting vast ice masses, so wildlife adapts by annual migrations. The majority of Antartica is a vast barren permafrost. Only 3% of the coast and peninsular peaks are where life migrates to in the spring, for a short fertile summer, attracted by rich supplies of krill and fish. Only the Emperor penguin males breed 4 months in winter 100 miles inland. The Arctic has a more complete fauna which migrates back North from the continent. Here, the Polar bear is threatened because global warming defrosts its seal hunt platform ice too fast. Written by
Did You Know?
Himself - Narrator
Both poles of our planet are covered with ice. They're the largest and most demanding wildernesses of all. Nowhere else on Earth is seasonal change so extreme. It causes the ice to advance and retreat every year. And all life here is governed by that.
Planet Earth Theme
Written by George Fenton
Performed by BBC Concert Orchestra See more