大象传媒

With the lengthening daylight of March, a restless urge to travel stirs the caribou. Females - many of them pregnant - take up the lead, until thousands of animals are travelling north towards the open tundra. Ahead lies 600km and 2.5 months of relentless plodding through some of the Arctic's harshest weather to reach the traditional areas where they will give birth to their calves.