A look at what would cause a ferocious tiger shark to cuddle up with a diver and why pigs are swimming in the Caribbean; and what mysterious blobs have washed up by the thousands on the shores of Oregon.
The rains are late. It is the most brutal time of year. Babies born into drought face starvation. The weak and the injured are weeded out. Everything is desperate for rain. When it finally arrives, it is a downpour on an enormous scale. Alien creatures emerge into a different world. The wet season begins.
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.
Cameras follow Japanese macaques in the snow-covered mountains of Japan, as they gather at steaming hot thermal pools to bathe and socialise. Elsewhere in the cool mountains of Mexico, cameras capture a spectacular gathering of billions of monarch butterflies, and in Bavaria, Germany, Spy Beaver gains unique access to the secretive world of the beaver.
Professor Richard Fortey travels to northeastern China to see a fossil site known as the 'Dinosaur Pompeii' - a place that has yielded spectacular remains of feathered dinosaurs and rewritten the story of the origins of birds. Among the amazing finds he investigates are the feathered cousin of T-rex, a feathered dinosaur with strong parallels to living pandas and some of the most remarkable flying animals that have ever lived.
Professor Richard Fortey investigates the remains of ancient volcanic lake in Germany where stunningly well-preserved fossils of early mammals, giant insects and even perhaps our oldest known ancestor have been found. Among the amazing finds are bats as advanced and sophisticated as anything living today, more than 50-million-years-later; dog-sized 'Dawn' horses, the ancestor of the modern horse; and giant ants as large as a hummingbird.