Most species of birds are able to detect approaching predators during unihemispheric slow-wave sleep.

The common blackbird is one of a number of species which has unihemispheric slow-wave sleep.

Mallards have been observed to spend more time in unihemispheric slow-wave sleep than the birds towards the center.

While in unihemispheric slow-wave sleep, birds will sleep with one open eye towards the direction from which predators are more likely to approach.

The utilization of unihemispheric slow-wave sleep by avian species is directly proportional to the risk of predation.

They are thought exhibit unihemispheric slow-wave sleep, in which they sleep with half of the brain while the half remains active.

When migrating, birds may undergo unihemispheric slow-wave sleep in order to simultaneously sleep while visually navigating flight.

Unihemispheric slow-wave sleep seems to allow the simultaneous sleeping and surfacing to breathe of aquatic mammals including both dolphins and seals.

It is more beneficial to sleep using both hemispheres; however, the positives of unihemispheric slow-wave sleep prevail over its negatives under extreme conditions.

That is the ability to sleep with one cerebral hemisphere at a time, while the other hemisphere is awake (Unihemispheric slow-wave sleep).

Some aquatic mammals and some birds can sleep with one half of the brain while the other half is awake, so-called unihemispheric slow-wave sleep.

However, as they consciously need to breathe at the surface, they can rest only one-half of their brain at a time, known as unihemispheric slow-wave sleep.

Unihemispheric slow-wave sleep (USWS) is the ability to sleep with one half of the brain while the other half remains alert.

The phenomenon, known as unihemispheric slow-wave sleep, is thought to allow a snoozing bird to detect an approaching predator - literally keeping an eye out for the enemy.

It has been suggested that this species of dolphin utilizes this reversed version of the "group edge effect" in order to maintain pod formation and cohesion while maintaining unihemispheric slow-wave sleep.

Certain species, especially species of birds, that acquired the ability to perform unihemispheric slow-wave sleep had an advantage and were more likely to escape their potential predators over certain species that lacked the ability.

Many species of birds and marine mammals have advantages due to the capability to undergo unihemispheric slow-wave sleep including, but not limited to, an increased chance of the evasion of potential predators and the ability to sleep during migration.

Much information is still unknown about the usage of unihemispheric slow-wave sleep, since the inter-hemispheric EEG asymmetry that is viewed in more idle birds may not be equivalent to species of birds that fly more frequently.