Falling asleep unexpectedly for a few seconds is a sign of tiredness in humans – and can be dangerous in certain situations, such as when driving.
But chinstrap penguins take an average of more than 10,000 four-second micronaps per day, according to a study published Thursday in the journal Science. This allows them to sleep more than 11 hours a day.
According to the authors of this work, this species may have developed this trait due to the need to remain constantly vigilant.
According to her, this study shows that the benefits of sleep can be cumulative, even if it is fragmented, contrary to previous belief. 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.
During the breeding season, penguins have to look after their eggs, for example to protect them from birds of prey, while their partner sometimes goes looking for food for several days in a row. Males and females take turns on these trips.
The research team, led by Paul-Antoine Libourel from the Lyon Neuroscience Research Center, implanted electrodes in 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 while standing or lying down to incubate their eggs, for an average of 3.91 seconds, more than 10,000 times per day.
Those at the edge of the group slept longer, likely due to higher noise levels and physical contact with other penguins in the center of the colony.
The researchers didn’t directly measure whether these micronaps actually allowed the penguins to rest, but since they were able to reproduce, they concluded that this was indeed the case.
In humans, however, excessively interrupted sleep, such as sleep apnea, impacts cognitive function and could even accelerate neurodegenerative diseases such as Alzheimer’s.
“So what is abnormal in humans could be perfectly normal in birds and other animals, at least under certain conditions,” scientists wrote in a commentary also published in Science.
Originally posted 2023-12-01 01:00:16.