When Northern Elephant Seals need to sleep while they are at sea for many months, they do so in the water. These marine mammals are at sea for many months to migrate to different places to molt, mate, and then they get more rest once they reach the shore. There are hardly any breaks before they reach their destination, so they only sleep about a total of 2 hours a day. Northern Elephant Seals spend most of the year in the Pacific Ocean, where they hunt fish, squid, and other food. Because they are hunted by sharks and killer whales often, they can only dive for air for only 10 to 30 minutes.
Jessica Kendall-Bar a PHD candidate who studies marine mammals at the University of California, San Diego, said to that “it is important to map these extremes of sleep behavior across the animal kingdom,” and that she wanted to see if Northern Elephant Seals really sleep while diving, so they made special caps with motion detectors that recorded their brain waves. The researchers got two seals and took them from Ano Nuevo State Park on the cost of California, and released them at another beach 60 kilometers south of Ano Nuevo.
Also, Niels Rittenberg, who wasn’t involved with the new study, but has studied animal sleep said that “people had known that these seals dive almost all the time when they’re out in the ocean” which means that given the frequency of their dives, they probably do so while they’re sleeping too. The researchers looked for naptime dive motions in the motion tracking device on 334 Northern Elephant seals and found that while at sea, they only conk out at around 2 hours per day. But, when they come on land to mate and molt, they sleep for nearly 11 hours a day. If they want to sleep, they have to dive 60 to 100 meters below the surface, which is below predators so that they can rest safer and better.
Northern Elephant Seals are really cool creatures and only sleep for 20 minutes while on long underwater journeys, so that predators won’t eat them. The only time they can sleep a lot is when they’re molting and mating on land.
Jessica Kendall-Bar a PHD candidate who studies marine mammals at the University of California, San Diego, said to that “it is important to map these extremes of sleep behavior across the animal kingdom,” and that she wanted to see if Northern Elephant Seals really sleep while diving, so they made special caps with motion detectors that recorded their brain waves. The researchers got two seals and took them from Ano Nuevo State Park on the cost of California, and released them at another beach 60 kilometers south of Ano Nuevo.
Also, Niels Rittenberg, who wasn’t involved with the new study, but has studied animal sleep said that “people had known that these seals dive almost all the time when they’re out in the ocean” which means that given the frequency of their dives, they probably do so while they’re sleeping too. The researchers looked for naptime dive motions in the motion tracking device on 334 Northern Elephant seals and found that while at sea, they only conk out at around 2 hours per day. But, when they come on land to mate and molt, they sleep for nearly 11 hours a day. If they want to sleep, they have to dive 60 to 100 meters below the surface, which is below predators so that they can rest safer and better.
Northern Elephant Seals are really cool creatures and only sleep for 20 minutes while on long underwater journeys, so that predators won’t eat them. The only time they can sleep a lot is when they’re molting and mating on land.
