The annual migration of wildebeest through the plains of the Serengeti reaches its unforgiving apex at the banks of the crocodile-infested Mara River. Undeterred, the herd leaps in despite the deadly predators within. Join wildlife expert Jean du Plessis as he charts this epic and often-deadly journey.
Some of the biggest predators to walk the earth face a constant battle - their prey is heavily armoured, indigestible and sometimes even poisonous. What makes this struggle more remarkable is that these predators do not prey on animals - but on plants.
Nine miles off the coast of Oman, a zebra shark scans the ocean floor for crustaceans, while a menacing giant stingray floats by. Soon, night becomes day and new killers emerge, from toxic scorpion fish to crown-of-thorns starfish, both bringing coral devastation. Dive among these deadly marine carnivores.
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.
This episode is devoted to the evolution of reptiles. They are not as restricted as their amphibian ancestors, since they can survive in the hottest climates. The reason is their scaly, practically watertight skin. The scales protect the body from wear and tear and in the case of some species of lizard, such as the Australian thorny devil, serve to protect from attack. The horned iguana from the West Indies is also one of the most heavily armoured. The skin is rich in pigment cells, which provide effective means of camouflage, and the chameleon is a well-known example. Temperature control is important to reptiles: they cant generate body heat internally or sweat to keep cool.