Seven Worlds, One Planet

David Attenborough looks at life in North America, which is defined by extreme weather and seasonal change - from tornados that roar across the prairies, to arctic air sweeping through the humid, southern swamps. In winter, lynx prowl the snowy Yukon for snowshoe hares, while Florida manatees seek hot springs to escape the freeze, while in summer fireflies light up the forests at night. Plus, footage of roadrunners cruising the spectacular deserts of Arizona, and polar bears leaping from rocks to hunt beluga whales.