Hidden Kingdoms for the first time takes the viewer into a unique and unexplored miniature world, immersing you into the action-packed lives of the planet's smaller animals. This episode is the story of two young animals forced to grow up fast. In Africa's savannah, a baby elephant shrew learns how speed is the secret to survival amongst the largest animals on Earth; and in America, a young grasshopper mouse confronts the Wild West's deadliest creatures to stake a claim of his own

At the very end of East Africa's Great Rift Valley, there's a 'land that time forgot'--the rolling grasslands of the Luangwa Valley. Seemingly untouched plains teem with Africa's most iconic animals. Some are unique to this place, others are critically endangered elsewhere.
Here, prey exist in remarkable balance, each taking advantage of the secret at the heart of this Eden, the mighty Luangwa River and its dramatic annual transformation from dusty inferno to emerald paradise.

Grasslands cover one quarter of all land and support the vast gatherings of wildlife, but to survive here animals must endure the most hostile seasonal changes on the planet. From Asia's bizarre-looking Saiga antelope to the giant anteaters of Brazil, grassland animals have adapted in extraordinary ways to cope with these extremes. In the flooded Okavango, lions take on formidable buffalo in epic battles, on the savannah bee-eaters take advantage of elephants to help catch insects and, on the freezing northern tundra, caribou embark on great migrations shadowed by hungry Arctic wolves.

East Africa is a land which is constantly changing. To survive here, creatures must be able to deal with unpredictable twists and turns - wet turning to dry, feast to famine, cold to hot - no matter how hostile it becomes. From dense forests to snow capped peaks, steamy swamps and endless savannah, this unique and varied land is also a haven for life, supporting large animals in numbers found nowhere else on Earth. But away from the familiar, forever-travelling herds, there are a huge cast of other characters - lizards that steal flies from the faces of lions, vast dinosaur-like birds who stalk catfish through huge wetlands, and an eagle who risks everything on the arrival of ten million bats from a far off rainforest.

In the last episode, Iain discovers the remarkable impact of just one plant: grass. On the savannah of South Africa he sees how grass unleashed a firestorm to fight its greatest enemy, the forests. He shows how cutting your finger on a blade of grass shows us how it transformed life in the oceans. In Senegal, he meets the cleverest chimps in the world. And, in the ruins of the oldest temple on Earth, he tells the extraordinary story of how grass triggered human civilisation.

Join us on a journey into the mysterious depths of the human psyche as we investigate the strange and surprising terrain of the Mind Field.
Chimps and Humans can be traced biologically back to a common ancestor. The Cognitive Tradeoff Hypothesis theorizes about the two different paths of development - particularly cognitive development - that occurred in these two species after the split. Chimps stayed in the trees and developed some extraordinary cognitive capabilities which are shown by the research work of Japanese scientists, while humans came down into the savanna and developed social capabilities and language.
The hypothesis is that humans 'traded' some aspects of cognitive capabilities by re-purposing areas of the brain that had evolved in the context of other uses. Those capabilities are kept in chimps and are far surpassing that of normal humans. This is shown by the research work of scientists at the Primate Research Center connected with Kyoto University.