Dolphin Sleeping Habits
Dolphins are able to put half of their brains to sleep while the other half remains conscious, an evolutionary trick that lets them rest while continuing to surface for air and stay alert to predators.
New research shows that dolphins can maintain round-the-clock vigilance for at least five days without experiencing any physical signs of sleep deprivation.
Researchers from the U.S. Navy Marine Mammal Program in San Diego and Tel Aviv trained two dolphins to respond to a 1.5-second beep sounded randomly against background noise of half-second beeps every 30 seconds. The beeps were low in volume and barely noticeable as the dolphins swam through their enclosure, according to the study, published in the May 1 issue of the Journal of Experimental Biology.
Even after five days without a break, the dolphins' response to the auditory cue remained as sharp as it was at the outset of the test.
