10 Birds that Sleep While Flying
Birds have fascinated scientists and nature enthusiasts for centuries with sleep while flying. One of the most incredible abilities observed in certain species is their capacity to sleep while flying.
This phenomenon, known as unihemispheric slow-wave sleep (USWS), allows birds to rest one hemisphere of their brain while keeping the other active for navigation and avoiding predators. Let’s dive into the list of 10 birds that own this extraordinary skill and explore how they do it.
10 Birds that Sleep While Flying
1. Alpine Swift
Alpine swifts are renowned for their long migrations, traveling thousands of miles between Europe and sub-Saharan Africa. These birds can remain airborne for up to 200 days, using USWS to rest during their epic journeys.
Fun Fact: Alpine swifts often glide effortlessly during sleep, conserving energy while staying in motion.
2. Frigatebird
Frigatebirds are masters of aerial endurance, capable of staying aloft for weeks at a time while searching for food over vast oceans. They sleep in short bursts of only a few seconds to minutes while soaring.
Fun Fact: Despite their ability to sleep while flying, frigatebirds still spend much less time asleep compared to when they are on land.
3. Common Swift
The common swift holds the record for the longest continuous flight, staying airborne for up to 10 months. Their entire lives are spent on the wing, except during breeding.
Fun Fact: Common swifts can travel over 3 million miles in their lifetime, equal to circling the Earth 120 times!
4. Northern Gannet
These seabirds migrate long distances across the Atlantic, often traveling nonstop for days. During these migrations, they rely on their ability to doze off mid-flight without losing their way.
Fun Fact: Northern gannets have a unique diving technique, plunging into the water at high speeds to catch fish.
5. Bar-Tailed Godwit
Bar-tailed godwits are famous for their non-stop transoceanic migrations, flying over 7,000 miles without stopping. Their ability to rest in flight helps them endure these extraordinary journeys.
Fun Fact: These birds can shrink their internal organs, like the digestive system, to reduce weight during long flights.
6. Sooty Tern
Sooty terns spend months over open oceans, only returning to land for breeding. They sleep while gliding over the waves, using their sharp instincts to maintain course and avoid danger.
Fun Fact: Sooty terns are sometimes called “wide-awake birds” due to their alertness, even during sleep.
7. Manx Shearwater
Manx shearwaters are known for their incredible navigation skills, traveling thousands of miles to and from breeding grounds. They sleep in short bursts while flying over the ocean.
Fun Fact: These birds have been recorded flying over 30,000 miles in a single year.
8. Great Frigatebird
A close relative of the frigatebird, the great frigatebird spends most of its life in the sky. They can sleep for just a few seconds at a time while riding air currents.
Fun Fact: Unlike other seabirds, frigatebirds cannot land on water because their feathers are not waterproof.
9. Swallow-Tailed Kite
Swallow-tailed kites are graceful birds of prey that migrate over long distances. They are believed to rest one hemisphere of their brain during flight to stay alert to potential dangers.
Fun Fact: These kites are known for their acrobatic flight patterns, often seen soaring and gliding effortlessly.
10. Wandering Albatross
The wandering albatross, with the largest wingspan of any bird, spends most of its life at sea. They use wind currents to glide for hours, sleeping briefly while on the move.
Fun Fact: Wandering albatrosses can travel over 500 miles in a single day without flapping their wings.
How Do Birds Sleep While Flying?
The secret lies in unihemispheric slow-wave sleep (USWS). During USWS:
- One side of the bird’s brain remains active, while the other sleeps.
- The open eye on the active side keeps watch for predators or obstacles.
- Birds often glide or soar to cut energy use while sleeping.
This adaptation is crucial for species that spend extended periods in the air, allowing them to maintain their migratory routes without interruption.
Why Do Birds Sleep While Flying?
- Energy Conservation: Birds with long migration routes cannot afford frequent stops.
- Predator Avoidance: Staying airborne reduces the risk of predation.
- Navigation: Certain species use environmental cues, like the Earth’s magnetic field, to navigate even during sleep.
Conclusion
The ability to sleep while flying showcases the remarkable adaptations of birds to their environments. From the tireless common swift to the determined bar-tailed godwit, these avian wonders inspire awe with their endurance and resilience. Understanding these unique behaviors highlights the marvels of evolution and the delicate balance of the natural world.
Did you know birds could sleep while flying? Which one surprised you the most? Share your thoughts in the comments!