On April 20, 2023, scientists discovered that Northern elephant seals only sleep in the sea for 2 hours per day. Jessica Kendall-Bar, who works at the University of California as a postdoc fellow, on the contrary, her team discovered that the Northern elephant seals sleep for more than 12 hours a day on land! “People had known that these seals dive almost all the time when they’re out in the ocean. But it wasn’t known if and how they sleep,” says Neil Rattenborg, who wasn’t involved in this investigation, but had also studied animal sleeping cycles. He works at the Max Planck Institute in Germany.
Kendall-Bar’s team really wanted to find out if Northern elephant seals actually sleep in the water! In order to do this, they had to suit two Northern elephant seals from the Año Nuevo State Park with unique caps. Movement detectors were also fastened on to the seals. The unique caps recorded the Northern elephant seals’ brain waves. After looking at the signals and motion data, Kendall-Bar’s team had figured out how the seals moved while they were napping.
The information confirmed that when a Northern elephant seal wants to take a nap, it first plunges 60-100 meters down. Then, it starts gliding freely. Later, the seal holds itself vertically for several minutes. Suddenly, the seal tumbles into a stage of sleep, that is identified as REM slumber. In the stage, the seal’s body stays numbed as the seal flips upside-down and glides in a calm swirl towards the marine floor. After 5-10 minutes, it swims back up. This whole procedure takes approximately 20 minutes, according to ScienceNewsExplores.
Now that Jessica’s team knew how the seals moved throughout sleep, they could pick out rests in motion information from other seals who were not wearing the special caps. After a while, investigators at Jessica’s team had already examined for napping nose-dives on 334 other Northern elephant seals! Those seals had been put on tags from 2004-2019.
According to Maria Temming, who writes for ScienceNewsExplores, when the Northern elephant seals nap on the beach, they can conk out a constant 11 hours of slumber. Rattenborg also confirms that “What the seals do at the beach might be something like what we do when we sleep in on the weekend.” Neil says.
Kendall-Bar’s team really wanted to find out if Northern elephant seals actually sleep in the water! In order to do this, they had to suit two Northern elephant seals from the Año Nuevo State Park with unique caps. Movement detectors were also fastened on to the seals. The unique caps recorded the Northern elephant seals’ brain waves. After looking at the signals and motion data, Kendall-Bar’s team had figured out how the seals moved while they were napping.
The information confirmed that when a Northern elephant seal wants to take a nap, it first plunges 60-100 meters down. Then, it starts gliding freely. Later, the seal holds itself vertically for several minutes. Suddenly, the seal tumbles into a stage of sleep, that is identified as REM slumber. In the stage, the seal’s body stays numbed as the seal flips upside-down and glides in a calm swirl towards the marine floor. After 5-10 minutes, it swims back up. This whole procedure takes approximately 20 minutes, according to ScienceNewsExplores.
Now that Jessica’s team knew how the seals moved throughout sleep, they could pick out rests in motion information from other seals who were not wearing the special caps. After a while, investigators at Jessica’s team had already examined for napping nose-dives on 334 other Northern elephant seals! Those seals had been put on tags from 2004-2019.
According to Maria Temming, who writes for ScienceNewsExplores, when the Northern elephant seals nap on the beach, they can conk out a constant 11 hours of slumber. Rattenborg also confirms that “What the seals do at the beach might be something like what we do when we sleep in on the weekend.” Neil says.