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.
Fish dominate the planet's waters through their astonishing variety of shape and behaviour. The beautiful weedy sea dragon looks like a creature from a fairytale, and the male protects their eggs by carrying them on his tail for months. The sarcastic fringehead, meanwhile, appears to turn its head inside out when it fights. Slow-motion cameras show the flying fish gliding through the air like a flock of birds and capture the world's fastest swimmer, the sailfish, plucking sardines from a shoal at 70 mph. And the tiny Hawaiian goby undertakes one of nature's most daunting journeys, climbing a massive waterfall to find safe pools for breeding.
In this first episode they travel from July to the December solstice, experiencing spectacular weather and the largest tides on Earth. To show how the Earth's orbit affects our lives, Helen jumps out of an aeroplane and Kate briefly becomes the fastest driver on Earth.
Andrew Scott narrates a special programme which celebrates winter and explores how animals and plants rise to the challenges it brings. With their world encased in snow and ice, animals must find the most inventive ways to survive and even benefit from the cold. Caribou become ice road travellers as it gets slippery underfoot, stoats make their own fur bedding, and snow monkeys find a warm bath. Emperor penguins are built for the cold weather, but even they must find their own tricks to endure the world's most savage winter.
In this first episode, he investigates how and why birds communicate, looking at the reasons snipe use their tail feathers to make a very distinctive noise and what's happening when thousands of starlings participate in stunning aerial displays in Aberystwyth.