As winter approaches and the wind drives temperatures down to minus 30 degrees Celsius, most animals have already migrated to survive, but the reindeer remain. Their double-layered coat provides insulation, and their wide, splayed feet act as natural snowshoes, helping them navigate the mountain plateau in search of the best winter food. Much of the time, they lie still to conserve energy, but when the wind drops, the herd comes alive. At this time of year, it is the females who take charge. Wit

100 days, seven continents, the journey of a lifetime. Join Will Smith as he travels pole to pole with scientists conducting groundbreaking research at the edges of the world. #PoleToPole with Will Smith premieres January 13 at 9/8c on National Geographic TV. Streaming on Disney and Hulu. | National Geographic