Diablo the giant otter lives in a lake in the jungles of Peru, with his unruly family of six cubs. Even at the tender age of six months, they need to learn how to survive in this dangerous paradise. Their dad teaches them to swim and eventually to catch piranha for themselves, but they must also learn to stay away from the neighbours from hell - the giant caiman. These large members of the crocodile family are a real threat to the giant otter family and Diablo must go to extraordinary lengths to try to protect his cubs. Charlie Hamilton-James returns to the place he first filmed Diablo. Following the family over several months, sometimes in very difficult conditions, he discovers how perilous a home this is for the cubs and watches them develop under the careful guidance of their father. He also films remarkable scenes of the giant otters fighting caimans.
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.
With the arrival of spring, days grow longer and temperatures rise. But spring in Alaska is short. Animals have two months to feed, and start a family, while avoiding predators. Spring is also the time that millions of birds return to Alaska.
Every year the black cap warbler undertakes a mysterious migration. This discreet journey covers thousands of kilometers and triggers puzzles that scientists are still trying to understand today. Thanks to cutting-edge technology, we will track the black caps on their journey.