Sir David Attenborough journeys into the hidden world of forests, where lives are entwined in the most unexpected of ways. From the temperate rainforests of Canada, where rarely seen ‘spirit bears’ fish for salmon, to the teak forests of India, where whistling wild dogs work together to bring down prey three times their size, the forests of planet Earth are full of unseen connections.

To stand out in the misty mountainous forests of China, male tragopan have developed a comical dance routine, whilst in the dense tropical rainforest, treehoppers form surprising alliances to fight off assassin bugs, and oriental pied hornbills go to incredible lengths to protect their young.

Even though we are only now beginning to understand how deeply interconnected life in the forest is, we do know that those connections are threatened by deforestation. Each individual tree is an intricate ecosystem in its own right, yet humans cut down 15 billion of them every year. In the Amazon, they are being replaced by plantations of a single species of tree – eucalyptus – which turn rich and complex worlds into little more than green deserts. In the small patches of remaining forest, animals like chimpanzees, our closest relatives, are forced to carve out an existence in the human world. Show less