Different mammals sleep in different amounts. While Koalas sleep up to 22 hours a day, the African elephant is known as a mammal that holds the record for sleeping the least of any mammal, with just around two hours a day.
But the largest living mammals on earth have some competition at sea now!
Research has found that Northern elephant seals can sustain themselves on about two hours of sleep a day. That too in 10-minute short naps hundreds of feet below the ocean’s surface.
The recordings, collected from the seals during more than 100 dives, found that the seals would often spiral downwards while dreaming and occasionally sleeping while resting on the seafloor.
Scientists believe that sleeping while diving allows the seals to avoid predators.
Researchers believe that seals are most vulnerable to predators like sharks and killer whales while at the ocean surface. So, sleeping in the deep allows the seals to power nap without being eaten by prowling predators.
Seals can hold their breath for a long time, they spend only a few minutes on the surface to breathe and then dive down. As they go deeper, their brain activity starts to slow, they go into a deep slumber and begin to glide.
