These penguins take 10,000 little naps a day — seconds at a time

Sleep. It's an essential biological function that has long intrigued scientists.

Similar to the book Everyone Poops, most animals sleep. Scientists have studied everything from mice to fruit flies in the lab to get a better understanding of what happens when animals sleep — and why so many do it. However, gathering data on how animals sleep in their natural habitat has always been tricky and hard to do.

But scientists did just that with wild chinstrap penguins in Antarctica. In doing so, researchers found birds in the nesting colony took over ten thousand microsleeps throughout the day – amounting to a whopping 11 hours of sleep.

Their work was published Thursday in the journal Science.

Vladyslav Vyazovskiy, a sleep neuroscientist at the University of Oxford not affiliated with the study, is excited about this new data because "most of what we know about the fundamental biology of sleep was obtained in laboratory conditions, in standard artificial conditions, which are radically different from conditions where sleep evolved. Context matters."

Researchers found that the microsleeps last mere seconds. Researchers think that being able to sleep for such short intervals might help the animals avoid predators that might be more likely to strike if the penguins were asleep for longer — especially considering that one parent goes out feeding in the ocean for days, leaving the other parent to protect the eggs from predatory birds.

Microsleep is much shorter than the minutes-long micronaps that have been shown to benefit humans. And study co-author Paul-Antoine Libourel, a researcher at the French CNRS in the Neurosciences Research Center of Lyon, is careful to not mix this insight about the success of microsleeps in penguins with how humans would fare. "This is not related to human physiology, and won't tell us more about the function of [human] sleep."

Although this study isn't a collective win for human sleep, the research is still a data collection win for human researchers.

To study the penguins, scientists implanted devices into a small group of penguins' brain and neck muscles. These brain wave and location data coupled with filming these birds in the nest gave robust sleep data. The equipment had never been used before, so this data collection was only supposed to be a test. However, the process went so well, the data was published in this study.

The study is an early insight into a relatively large vacuum of scientific knowledge about sleep. "Pretty much every study on sleeping birds discovers something new, something we didn't know about before," says Libourel.

Want to hear more adorable research about the animal kingdom? Email the show at shortwave@npr.org.

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This episode was produced by Berly McCoy and Vincent Acovino. It was edited by Brent Baughman, Rebecca Ramirez and Kathryn Fox. Brit Hanson checked the facts. The audio engineers were Robert Rodrigues, Kwesi Lee and Maggie Luthar.

Copyright 2023 NPR. To see more, visit https://www.npr.org.

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