In the vast South Atlantic, huge pods of dolphins, massive penguin colonies and the largest gathering of marine mammals on earth pack chains of extraordinary islands, created by powerful volcanic forces far below them. Nutrient-rich upwellings create profusions of life in some areas, whilst extreme isolation and abyssal depths host a world of bizarre creatures in others.
In the last 30 years the world's urban areas have almost tripled in size, changing at a rate wildlife has never experienced before. As cities are built, animals are pushed out of their natural homes. Their stories are the most surprising and captivating of all. Today, these 'wild outcasts' find themselves fighting for their place in a land that once belonged to them. In this episode we feature elephants in Sri Lanka and see that competition between them and humans for land and resources is resulting in deadly territorial conflicts, which demand solutions. And on the Pacific coast of Costa Rica we meet a troop of capuchin monkeys and learn how our behaviour is affecting them, and raising big questions about their future. But we also discover where we learn to live with wildlife as neighbours, and give it the space and resources it needs, it can thrive. The resulting relationships between human and animals can be mutually beneficial. We meet an Amsterdam heron called Kiri who has been visiting the same house twice a day for the last 17 years, befriending its owner, and the Florida manatees whose population has recovered to such an extent under the guardianship of local human residents that, in recent years, they have been taken off the endangered species list, and contributed to a massive boom in the local tourism industry. We meet the swiftlets who have evolved to live only in people's houses and specially built swiftlet hotels in Indonesia. And the surprising story of a population of tiny foxes on a Californian island whose presence benefits the hardened military personnel of a US naval base. This hopeful but realistic episode culminates with the return of charismatic ocean giants to the world's most iconic city, as humpback whales breach against the New York skyline.
In the final episode of this groundbreaking scientific study, Liz Bonnin and a team of scientists reveal the secret language of our cats, the surprising conversations they have when we are asleep, and why they meow to us but not each other. We rig a house with cameras and cat trackers to discover if four cats living under one roof all get on as well as we would like to think. And we find out why living alongside us is making life difficult for our 21st-century cats.