Dolphins Sleep With Half Their Brains

On October 19th 2012, researchers have found that Dolphins can stay constantly alert for two weeks without even taking as much as a nap!

Dolphins use half of their brain to sleep but also the other half keeps working. This is unlike us humans and other mammals because we have to stop everything and completely shut our brains down to sleep at night.

Dolphins would become prays for the sharks if they shut their brains down completely! So half of their brains rest, while the other side stays awake. Dolphins can decide and flip around which side of the brain rests so that the other side is never too tired, while the other is well-rested.

To see just how well dolphins can function after 15 days of sleeping with half of their brain at a time, researchers set up an underwater test for the dolphins to see how good their echolocation skills are. When the water is dark the surroundings make a clicking noise which bounces off of objects and lets the dolphin know there is something there, even if they can't see it. The dolphins were trained to press a paddle if they detected a certain sound from the sound projectors when they sent out echolocation clicks. Researchers set up a floating pen made up of eight different groups of microphones and sound projectors.

The performance from the Dolphins are very colse to perfect, suggesting they could keep functioning forever without actually shutting down all of their brain to sleep. However the dolphins were not further tested.