In celebration of his ninetieth birthday, Sir David Attenborough shares extraordinary highlights of his life and career with broadcaster Kirsty Young.

The series will celebrate the diversity of life on each of these continents, but also the challenges faced by animals in a modern world.

Antarctica - the coldest, windiest, most hostile continent. Only the toughest can survive here. But the ocean here is warming and with that comes an uncertain future.

Asia - where rarely seen animals roam the hottest deserts, tallest jungles and highest mountains on Earth.

South America - the most species-rich continent on earth. From the volcanoes of the Andes to the world’s largest rainforest, animals here must specialise to carve out a niche.

Australia, a land cast adrift at the time of the dinosaurs. Isolated for millions of years, the weird and wonderful animals marooned here are like nowhere else on Earth.

Europe - a continent transformed by mankind, where extraordinary animals are found in surprising places.

North America - a land of change where pioneering animals make the most of surprising opportunities.

Africa - home to the greatest wildlife gatherings on earth. But even in this land of plenty, wildlife faces huge challenges.