Island of Marvels

Madagascar, the world's oldest island, broke off from Africa and India and has been on its own for more than 70 million years. In splendid isolation, it has evolved its very own wildlife - more than 80 per cent of it is found nowhere else. And that wildlife is quite extraordinary. In this episode, we reveal the island's most bizarre and dramatic places, and the unique wildlife that has made its home in each, thanks to the geology and isolation of this Alice-in-Wonderland world.

The stars are the lemurs, Madagascar's own primates. A family of indris leaps like gymnasts among rainforest trees; and crowned lemurs scamper around Madagascar's weirdest landscape, the razor-sharp limestone tsingy, which looks like something from another planet. And sifakas, ghostly white lemurs, move like ballerinas across the forest floor.

Madagascar's wildlife is famously strange. Bright red giraffe-necked weevils use their necks to build leaf nests with the complexity of origami. Chameleons stalk the forests, none more intriguing than the pygmy chameleon, the world's smallest reptile, delicately courting a female in its giant world. The fearsome fossa, Madagascar's only big mammal predator, looks for a mate - 15 metres up a tree. And in the southern 'spiny desert', a spider hauls an empty snail shell, 30 times its own weight, up into a bush as a shelter; something never before filmed, and possibly never observed in the wild before.

At the end of the episode, we go 'behind the camera', to reveal the challenges of capturing the behaviour of the little-known wildlife of this island. How do you go about filming a rare, secretive lemur that lives in the middle of Madagascar's biggest lake?