Stephen Fry concludes his look at ‘A Year on Planet Earth’

Stephen Fry is on the last leg of his journey.

Autumn is the season of change. For many, change brings opportunity, but it also brings huge challenges.

In Northern Canada, the cold is felt early, by September temperatures can plummet as low as -20C. But there is one stretch of river that still flows, and ‘ice bears’ are able to fish for the final salmon of the season. Those that can’t survive the cold weather, need to get on the move.

Monarch butterflies emerge, and set off on a mammoth migration to Mexico – 2500 miles south. South of the Equator, it is the toughest time of the year in Southern Africa

The rains have been gone for many months, and watering holes have all-but dried up. An elephant calf is dangerously vulnerable to predators. Nearly a year old, its time for a king penguin chick on Marion Island to answer the call of the ocean. She’s replaced her fluffy coat with tightly-packed waterproof feathers. It is time for her first ever swim, but troubled waters are ahead.

A Year on Planet Earth, ITV1 and STV, 8pm