The animal known to have the largest migration is the "Caribou" (or reindeer), particularly the herds found in North America. Caribou undertake immense migrations, traveling thousands of miles between summer and winter grazing grounds. This seasonal migration is primarily driven by the search for food and mating opportunities. During migration, caribou navigate through harsh weather conditions and various landscapes, showcasing their incredible endurance and adaptability. Other species, like the Arctic Tern, also have notable migrations; however, in sheer distance, the caribou's journey is one of the most remarkable in the animal kingdom.