A Year on Planet Earth: Autumn

Stephen Fry looks at autumn in the northern hemisphere and spring in the south, seasons of change that bring opportunities, but also huge challenges. By September temperatures in northern Canada can plummet as low as -20C, but there is one stretch of river that still flows and bears are able to fish for the final salmon of the season. In southern Africa the rains have been gone for many months and watering holes have all-but dried up, while a king penguin chick on Marion Island answers the call of the ocean