A butterfly that travels from Canada to Mexico to hibernate and reproduce, a whale that holds its species' record with 22,500 kilometers of travel across the oceans, or the arctic tern, a bird that -attention, spoiler- holds the longest migration in the animal kingdom. Now that spring is beginning and with it many species are on the move, we explain the main migratory routes of planetary fauna. The highways of wildlife.

According to a study published in the journal Regional Environmental Change (2025), opting for trains instead of planes could avoid up to 662,000 tons of CO₂ emissions annually and offset up to 87% of the negative economic impact associated with the airline sector. The study itself reveals that a high-speed train generates only 23 grams of CO₂ per passenger, compared to the 192 grams emitted when traveling by plane. In short, traveling by train is one of the most sustainable vacation choices we can make. There are many options around the world, some of which involve long journeys that even create continents. Let's discover them.