According to an international team of researchers, birds have been seen sleeping while flying. However, they just use one hemisphere of their brain and do so for very short periods of time.
The German team noted that the birds that can fly for the most amount of time are the red-breasted ones. Two mounts of continuous flying without landing to sleep is, to say the least, very impressive.
After monitoring 14 red-breasted birds, the researchers have discovered that they sleep for about 41 minutes daily, even though they fly.
The power naps usually take about 12 seconds each, and the birds manage to use only half of their brain to do so. While circling in raising air currents when it’s not necessary to flap their wings, the birds manage to fall asleep.
The brain hemisphere connected to the eye facing the direction of the movement is more likely to stay awake, but that doesn’t always apply. This is believed to happen mostly to avoid impact with other birds that also sleep in the same air mass.
It is similar to how mallard ducks sleep when they are in a group. The ones sitting in the exterior keep the eye that’s facing outwards open so they can warn the other if anything dangerous occurs.
To truly determine whether birds sleep during flight researchers needed to analyze the brain’s changes and activities that classify wakefulness from the two stages of sleep discovered at birds: rapid eye movement and slow-wave sleep. To do so, they designed a device that measured electroencephalographic changes in head movement and changes in brain activities.
Not having waterproof wings and being unable to dive in oceans, the red-breasted birds are believed to have adapted to sleeping while flying to survive.
Given how sleep deprivation affects so many other species, including our own, scientists agreed that many future studies must be conducted on these birds to find out how they can survive with such small amounts of sleep.
It is still a mystery why we and other animals suffer so much from the lack of sleep while some birds can adapt with far less sleep without having any impact on their condition.