A polar bear mother keeps watch over her cub as they wait for the coming winter and the plentiful feeding opportunities it brings. But there are threats abound: from cannibalistic male bears, to the devastating impact of climate change, which has delayed the seasonal freeze and put them at risk of starvation.
The riverbeds that carve their way through the Kgalagadi Transfrontier Park offer a tantalizing promise of life, as well as a fierce test of survival. Explore the hidden lifelines that create a fragile link for the creatures that inhabit this unwelcoming wilderness.
In this episode Brian uncovers how the stunning diversity of shapes in the natural world are shadows of the rules that govern the universe. In Spain he shows how an attempt by hundreds of people to build the highest human tower reveals the force that shapes our planet. In Nepal, honey hunters seek out giant beehives that cling to cliff walls. The perfect hexagonal honeycombs made by the bees to store their honey conceal a mathematical rule. Off the coast of Canada, Brian explains how some of the most irregular, dangerous shapes in nature - massive icebergs that surge down from Greenland and into shipping lanes of the Atlantic - emerge from a powerful yet infinitely small force of nature. Even the most delicate six-sided snowflake tells a story of the forces of nature that forged it.
In the vast South Atlantic, huge pods of dolphins, massive penguin colonies and the largest gathering of marine mammals on earth pack chains of extraordinary islands, created by powerful volcanic forces far below them. Nutrient-rich upwellings create profusions of life in some areas, whilst extreme isolation and abyssal depths host a world of bizarre creatures in others.