By: Daniel Xia

Northern elephant seals have become known for their amazing power naps. They swim for months and only sleep twenty minutes at a time, adding up to an average of only 2 hours a day.

They spend most of their time in the Pacific Ocean, hunting for food. However, they face threats from sharks and killer whales, making them vulnerable at the sea surface. To stay safe, they come up for air only briefly between 10 to 30-minute dives. As marine mammal expert Jessica Kendall-Bar explains, “It’s a delicate balance they’ve evolved to maintain their survival amidst an unforgiving oceanic environment.”

When northern elephant seals want to sleep at sea, they dive deep, reaching 60 to 100 meters (200 to 360 feet) below the surface. As they doze off, they hold themselves upright for a while before slipping into REM sleep, where their bodies become paralyzed. They then flip upside-down and gently drift towards the seafloor, sometimes descending hundreds of meters. This remarkable sleep routine keeps them safe from sharks and killer whales. As Jessica Kendall-Bar puts it, “It’s a delicate balance they’ve evolved to maintain their survival amidst an unforgiving oceanic environment.”

The sleep habits of the northern elephant seal are truly amazing and demonstrate their amazing adaptability. Studying these creatures gives us valuable information about animal behavior and reminds us of the wonders of nature.