The Surprising Sleep Habits of Elephant Seals

Elephant seals sleep just two hours daily in a series of short naps while performing deep dives, according to groundbreaking research that recorded brain activity in a free-ranging, wild marine mammal. During the months they spend at sea, elephant seals rival the record for the least sleep among all mammals, typically sleeping in 10-minute bursts during deep, 30-minute dives, often spiralling downwards while dreaming, and occasionally lying down for a nap on the seafloor. The scientists believe that sleeping while diving allows the seals to avoid predation.