Any number of whales could be placed on this list as great migrators. Our oceans are interlaced with corridors that whales use in finding calm waters to birth their calves or cold waters to consume their share of krill. The gray whale serves as a premiere example of these marine mammals’ nomadic way of life. Hunted to near extinction by the early 20th century (and extirpated from the European coast), these creatures have made a comeback in the North Pacific Ocean. Every autumn, a group of these whales embark on a 3-4 month journey that begins in the Chukchi Sea and ends in the basking warm waters of Mexico. Since they are often chased by orcas, these gentle giants saunter along best they can. The Pacific gray whale migration is highly documented and has become a great source of ecotourism.