Autumn

This episode follows the polar autumn: temperatures are dropping, seas are freezing, and arctic animals migrate south away from the expanding ice. Animals highlighted in this episode include the polar bear, the beluga whale (Delphinapterus leucas), Brünnich's guillemot (Uria lomvia) being hunted by Arctic foxes (Vulpes lagopus), the muskox (Ovibos moschatus), the caribou, the southern giant petrel (Macronectes giganteus), the South Georgia pintail (Anas georgica georgica), the Adélie penguin being hunted by leopard seal (Hydrurga leptonyx), and the emperor penguin (Aptenodytes forsteri).