14. Albatrosses
Albatrosses are legendary for their long, uninterrupted journeys over the open ocean. These majestic birds can sleep on the wing, taking advantage of unihemispheric slow-wave sleep to rest one side of their brain while gliding effortlessly above the waves.
This adaptation allows them to remain airborne for months at a time without ever needing to land, making them some of the most remarkable travelers—and sleepers—in the avian world. BBC Earth