Cameras follow desert elephants seeking sustenance, bison roaming North American grasslands and caterpillars living the good life underground.

Tony works jobs from the Middle ages, 1000 to 1500 AD. This is the time of castle building and cathedral construction. What do you do to get a piece of crust? Tony Robinson presents some of the worst jobs ever from various historical periods in England, ranging from the dark ages through the Victorian era. Season one focuses on historical periods, while season two combines places, social status and periods of time (for example, rural, urban, maritime, etc.). From the channel 4 website: "The history we are taught usually features the lives and times of the great and the good, of the haves but not the have-nots. However, the monarchs, aristocrats and magnates could not have existed without the battalions of minions who performed the tasks that were beneath their masters and mistresses."

On the unforgiving frontier of climate change, polar bears, walruses, seals and penguins find their icy Edens in peril.

Chris turns his attention to his favourite type of vehicle - the motorcycle. He takes to the road on a Twenties Brough Superior - the first bike to reach 100mph - and rides through the badlands of Buckinghamshire with his own Harley-Davidson gang.