2023-11-30 21:47:08
Washington (AFP) – In humans, unexpectedly dozing off for a few seconds is a sign of fatigue — and can be dangerous in certain situations, such as while driving.
Published on: 11/30/2023 – 10:47 p.m. Modified on: 11/30/2023 – 10:45 p.m.
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But chinstrap penguins take more than 10,000 micro-naps of four seconds on average per day, according to a study published Thursday in the journal Science. This allows them to accumulate more than 11 hours of daily sleep.
This species might have developed this trait because of the need to remain constantly vigilant, according to the authors of this work.
According to them, this study shows that the benefits of sleep can be cumulative even if it is fragmented, contrary to belief until now. At least in some species.
Chinstrap penguins (Pygoscelis antarcticus) have an estimated population of nearly 8 million breeding pairs, and live primarily on the Antarctic Peninsula and islands in the southern Atlantic Ocean.
During the nesting period, penguins must watch over their eggs, in order to protect them, for example, from predatory birds, while their partner goes in search of food, sometimes for several days in a row. Males and females take turns making these trips.
The team of researchers, led by Paul-Antoine Libourel from the Lyon Neuroscience Research Center, implanted electrodes on 14 penguins from a colony on King George Island in December 2019.
They recorded electrical activity in their brains and neck muscles, and accelerometers and GPS were used to record their movements and location. All combined with direct observations and video recordings.
Result: the penguins fell asleep standing up or when lying down to incubate their eggs, lasting on average 3.91 seconds, more than 10,000 times per day.
Those located on the periphery of the group slept longer, probably due to the higher noise level and physical contact with other penguins in the center of the colony.
The researchers did not directly measure whether these micro-naps actually allowed the penguins to rest, but since they were able to reproduce, they deduced that this was indeed the case.
In humans, on the other hand, excessively interrupted sleep, for example in the case of sleep apnea, has consequences on cognitive functions, and might even accelerate neurodegenerative diseases such as Alzheimer’s.
“Thus, what is abnormal in humans might be perfectly normal in birds and other animals, at least under certain conditions,” scientists wrote in a commentary also published in Science.
© 2023 AFP
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