North America: no continent experiences seasonal change as extreme as North America.From tornados that roar across the prairies, to Arctic air sweeping through the humid, southern swamps, this is a land where pioneering animals thrive.In winter, lynx prowl the snowy Yukon for snowshoe hares, whilst Florida manatees seek hot springs to escape the freeze. In the creeks of Tennessee, fish build spectacular underwater pyramids to find a mate. Fireflies light up the forests during summer nights, roadrunners cruise the spectacular deserts of Arizona, and polar bears leap from rocks to hunt beluga whales.