These birds can sleep in flight with one or both hemispheres of their brain. They sleep mostly while circling in rising air currents, and keep one eye facing forward to watch their direction.
Frigatebirds
These birds use unihemispheric sleep to rest one brain hemisphere at a time while gliding over oceans for months.
Wandering albatrosses
These birds rely on micro-sleeps while flying during their epic non-stop migration.
Bar-tailed godwits
Great snipes are fast-flying birds that take short naps while migrating, allowing them to stay airborne and maintain their speed. These birds fly non-stop during migration, covering thousands of miles in a few days.
Great snipes
These birds nap mid-flight, using short bursts of rest while migrating across continents.
Northern wheatears
Some species of sandpipers sleep during migration by briefly resting in flight.
Sandpipers
These birds sleep briefly in flight, especially during migration. They can stay airborne for 10 months of the year, feeding and sleeping on the wing.