Finding somewhere to keep safe is one of the biggest challenges an animal faces. But some animals don't have to find a safe place - they build one. Chris reveals some of the best building animals in the world - a group that is incredibly varied. Accomplished animal architects include everything from beavers to bees and prairie dogs to bowerbirds. They don't only build homes, however - they also make structures to raise their young, store food, catch prey and impress mates. But what can be learnt from their building brilliance?
Steve Backshall reveals the incredible influence that insects and their close relatives have on Earth's many ecosystems. In the grasslands of South America the landscape has been created almost solely by one team of insects - grass-cutter ants. Across the world's oceans one tiny creature plays such a key role that, without it, the largest animal on our planet, the blue whale, could not exist. And in East Africa the savannah would quickly be swamped in dung were it not for the activities of a certain beetle. Yet the greatest influence of all comes from a group of insects that have ultimately changed the colour and diversity of our planet.
Liz Bonnin presents a controversial and provocative episode of Horizon, investigating how new scientific research is raising hard questions about zoos - the film explores how and why zoos keep animals, and whether they need to change to keep up with modern science, or ultimately be consigned to history. Should zoos cull their animals to manage populations? Liz travels to Copenhagen Zoo, who killed a giraffe and fed it to the lions, to witness their culling process first hand. They think it is a natural part of zoo keeping that is often swept under the carpet. Should some animals never be kept in captivity? In a world exclusive, Liz visits SeaWorld in Florida and asks if captivity drove one of their orcas to kill his trainer. But could zoos be the answer to conserving endangered species? Liz examines their record, from helping breed pandas for the wild to efforts to save the rhinos. She meets one of the last surviving northern white rhinos and discovers the future of this species now lies in a multimillion-dollar programme to engineer them for stem cells. Veteran conservation scientist Dr Sarah Bexell tells Liz the science of captive breeding is giving humanity false hope.
The second episode of the documentary series takes a look at bizarre and extraordinary feathered dinosaurs, many of which have only just been discovered. These feathered beasts are revolutionising our understanding of life on Earth as they blur the boundaries between what we know of dinosaurs and birds. China sits at the heart of the feathered dinosaur discoveries and is the home of one of the most unusual discoveries on Earth: the epidexipteryx. Only the size of a pigeon, this predator was the most bird-like of any dinosaur and is the first known case of ornamental feathers. But feathers were not just confined to the small. From caudipteryx to sinosauropteryx and the 8-metre-long gigantoraptor, feathers may have been used for flight, for insulation or even to intimate and attract. These dinosaurs not only hint at how animals might have developed flight, but also suggest that dinosaurs may still live among us today - as birds.
Despite their diminutive stature, little penguins are a formidable species. They spend months at sea hunting, they mate for life, and when gulls threaten to steal their hard-earned fish, they band together in groups for self-defense. Journey to the sandy beaches of Southern Australia, where the tiniest penguin species on the planet is living large.