Nesting Chinstrap penguins take over 10,000 naps a day (Credit: Eamonn Maguire eamonn/ CC0/ Wikimedia Common)

Adult Chinstrap penguins love their naps. A recent study found that the flightless birds take as many as 10,000 naps a day when nesting! Each snooze lasts about four seconds, adding up to a total of 11 hours. But at no point do the penguins fall into deep sleep.

Paul-Antoine Libourel and his team from Lyon Neuroscience Research Centre made this surprising discovery after studying 14 penguins incubating eggs. They were part of a colony of over 2,700 breeding pairs in Antarctica's King George Island. The scientists implanted small devices into the penguins' brain and neck muscles to monitor their brain activity. The information collected, coupled with video footage of the penguins in their nests, gave the scientists detailed data on the birds' sleep patterns.

The naps, called "microsleeps," can also occur in sleep-deprived humans. However, the strategy could prove dangerous in certain situations, like when driving a car or riding a bike. Also, scientists are not sure if ultra-short naps provide any benefits to humans.

Chinstrap penguin parents take turns looking after their young (Credit: Public Domain)

However, for Chinstrap penguins, the microsleeps are a crucial adaptation. During incubation, the parents take turns watching over the eggs. One guards the nest for several days at a time while the other goes foraging at sea. Deep sleep could put the eggs, or small chicks, at risk from predatory brown skua birds or even other penguins.

The scientists revealed their findings in the journal Science in November 2023. They state that Chinstrap penguins are not the only animals that can function on short bouts of sleep. However, they are the first ones observed to be able to do so for such an extended period.

"This is not unique across the animal kingdom. There are other animals that are sleeping quite fragmented or in very short bursts of sleep," said Libourel. "But, to our knowledge, they were not able to sustain such extreme sleep fragmentation of days and hours, day and night, and continuously [as these penguins]. And this is what was very interesting in our findings."

Chinstrap penguins live in the Antarctic and sub-Antarctic regions (Credit: Liam Quinn/ CC-BY-SA-2.0/ Wikimedia Commons)

Chinstrap penguins get their name from the narrow black band under their heads. The medium-sized birds stand about 30 inches (76 cm) tall and weigh between 7 to 13 pounds (3 to 6 kg). Closely related to the Gentoo and Adélie penguins, they are an abundant species in the Antarctic and sub-Antarctic regions.