Journey to secret worlds where lives are wrapped in unexpected of ways. The fifth episode of the series takes viewers into the fascinating world of forests, revealing their hidden complexities and the intricate relationships within. Initially perceived as tranquil, forests are in fact bustling with life and intricate ecological interactions. The episode showcases various species, each with its unique lifestyle and survival strategies. Highlights include the Oriental pied hornbills in Borneo, whose extraordinary nesting rituals and partner dynamics are captivating.
The Amazon rainforest is explored, introducing the peculiar treehoppers and their unique communication methods, vital for survival amidst numerous predators like ants and assassin bugs. The episode also delves into the intelligent and cooperative hunting techniques of dholes in the forests of India. The narrative takes a turn to China, focusing on the visually stunning courtship displays of Temminck's tragopans and golden pheasants. In the temperate rainforests of Western Canada, the rare spirit bear and its unique relationship with its habitat are examined.
The episode concludes with an insightful look at the impact of human activity on forests and their inhabitants, particularly focusing on chimpanzees in Uganda, whose survival is increasingly intertwined with human expansion.

The film tells the tale of Nim Chimpsky, a chimpanzee who was the subject of a landmark experiment to see if an ape could learn to communicate with language if raised and nurtured like a human child. This study was the brainchild of Dr. Herbert Terrace, a Columbia University behavioral psychologist who hoped to teach Nim enough language that he could eventually express what he was thinking and feeling. This would refute Noam Chomsky's thesis that language is inherent only in humans, hence his moniker, a direct pun on the famous linguists' name. The doc was a smash when it played at Sundance with this entirely different incredible but true story

The fourth episode plunges us into the heart of the jungle for an exciting story of power, politics, and survival. Days after a fierce battle with Western rivals, Jackson, the alpha male, grapples with the aftermath of his injuries. The strength of an alpha is paramount, and physical frailty can quickly translate into political vulnerability. While Jackson's allies waver, Abrams and Wilson see a golden opportunity to seize control.
As Abrams makes strategic moves against Jackson, the forest resonates with news of the ongoing power struggle, attracting the attention of external threats. Battles for leadership are perilous, with uncertain outcomes for both the reigning alpha and the ambitious challenger. This episode promises an intriguing exploration of chimpanzee society and their relentless pursuit of dominance.

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.

Jungles cover roughly three per cent of our planet yet contain 50 per cent of the world's species. High-definition cameras enable unprecedented views of animals living on the dark jungle floor. In the Ngogo forest the largest chimpanzee group in the world defends its territory from neighbouring groups. Other jungle specialists include parasitic fungi which infiltrate an insect host, feed on it, and then burst out of its body.