This moving film reveals the differing fortunes of a mother polar bear and a mother grizzly bear, and their new-born cubs, in a rapidly-changing world. The shrinking Arctic ice may be making life much tougher for polar bears, but it is offering new opportunities for grizzly bears to the south.

Where once the lives of white and brown bears could not have been more different, in summer-time they now meet along shores and islands almost all the way to the North Pole. Amazingly they have even interbred. It Is a remarkable story of how bears, ever intelligent and resourceful, are adapting to a warming world.