This episode is a pioneering exploration of the latest discoveries concerning the Amazon - by far the greatest river on Earth. It is the river of superlatives, flowing more than 4,000 miles from the Andes to the Atlantic. Its 1,100 tributaries drain the greatest river basin on the planet and along its incredible journey it collects and transports one-fifth of the world's fresh water. Due to its enormous size, it still hides secrets.
While most of the series has focused on conflict, this episode is all about co-operation. The suitably named social spiders spin one enormous, 30m web for the whole colony, a queen bee rules her hive with a strict hierarchy and some green ants show great team spirit to help build a nest together. There are no broken societies here. David Attenborough shifts the focus to bugs that prefer cooperation rather than conflict. They include burrowing cockroaches, the suitably named social spiders - which share a 30-metre web.
Isolated since the time of the dinosaurs, New Zealand's wildlife has been left to its own devices, with surprising consequences. Its ancient forests are still stalked by predators from the Jurassic era. It's also one of the most geologically active countries on earth. From Kiwis with their giant eggs, to forest-dwelling penguins and helicopter-riding sheep dogs, meet the astonishing creatures and resilient people who must rise to the challenges of their beautiful, dramatic and demanding home.