Sir David Attenborough reveals the world of mammals, uncovering the secrets of their success, from the tiny terrestrial Etruscan shrew to the biggest of them all, the blue whale.

The dark, a world of opportunity for mammals. More than two-thirds prefer the cover of the night, with some now returning to the safety of the shadows in order to avoid us.

Mammals have mastered every environment on Earth, but today the planet is changing faster than ever. Mammals must change with it to have a chance of survival in this, the new wild.

From freshwater jungle ponds to the dark depths of the open ocean, air breathing mammals have found remarkable ways to overcome the many challenges of a life in water.

From ice-covered seas to snow-capped mountains, mammals have conquered the cold, living in the harshest places on earth, thanks to their remarkable intelligence and adaptations.

From the barren Australian outback to the remote, dry deserts of Namibia, mammals use their ingenuity, incredible intelligence and remarkable resilience to beat the heat.

From deep in the undergrowth to the highest tree, forests are home to two-thirds of all mammal species. Discover how they overcome the many challenges of life in a crowded world.