Penguin Parents Engage in Microsleeping to Protect Newborns

December 6, 2023

Updated: December 6, 2023

WASHINGTON — It’s a challenge for all new parents: getting‍ enough sleep while keeping a close ⁤eye on their newborns. For some penguins, it means thousands of mini-catnaps a day, ⁤researchers discovered.

Chinstrap penguins in Antarctica need to guard their eggs and chicks⁤ around-the-clock in crowded, noisy colonies. So they nod off thousands of times⁢ each ‌day⁢ — but⁤ only for about four seconds at a time — to ⁣stay vigilant, ‍the researchers reported Thursday ⁢in the journal Science.

These⁣ short⁣ “microsleeps,” totaling around 11 hours‍ per day, appear to ‍be enough to keep the parents going for ‌weeks.

“These penguins look ⁣like drowsy drivers, blinking their eyes open and⁢ shut, and they do it ‌24/7 for ⁢several weeks at⁢ a time,”‍ said Niels Rattenborg, a sleep researcher at the Max Planck Institute ⁤for Biological‌ Intelligence in Germany ‍and co-author of the new ⁢study.

“What’s surprising is that ⁢they’re able ⁢to function ‌OK and ⁤successfully raise their⁤ young,” ⁣he said.

Chinstrap penguins, named ⁤for the thin line of black facial ⁣feathers resembling a chinstrap, usually lay their eggs in pebble nests in November.‍ As with many other kinds of penguins,⁢ mated pairs share parenting duties. One parent‌ tends to ⁣the eggs and⁣ chicks alone while the other goes off fishing for family meals.

While ‌the⁣ adults don’t face ⁣many natural ⁢predators in the breeding season, large⁣ birds called brown ‍skuas prey on eggs and small fuzzy gray chicks. Other adults may also try ⁤to ‍steal pebbles from ‍nests. So the devoted parents must be always on guard.

For the first⁣ time, the scientists tracked the⁣ sleeping ‌behavior of chinstrap penguins in⁢ an Antarctic⁣ breeding colony by attaching sensors ‍that measure brain waves. They collected data on 14 adults over 11 days on King George Island ‌off ⁤the coast of Antarctica.

The idea for the study ‍was hatched when Won Young Lee, a biologist at the Korean ⁤Polar Research Institute, noticed breeding penguins frequently blinking their eyes ⁣and apparently nodding⁤ off during his ⁣long days ⁤of field⁢ observations. But the team needed to ⁢record brain waves to ‍confirm they‍ were ⁢sleeping.

“For these penguins, microsleeps have some restorative functions — if not, they ‌could not endure,” he said.

The researchers did‌ not collect sleep data ⁢outside⁣ the breeding ⁣season, but⁤ they hypothesize⁣ that the ‍penguins may sleep in longer intervals at other times of ‌the year.

“We don’t know yet if‍ the⁤ benefits of microsleep are the⁣ same‌ as for long consolidated sleep,” said Paul-Antoine‌ Libourel, a co-author and sleep researcher at ⁤the⁣ Neuroscience Research Center of Lyon in France. ⁤They ‌also ⁣don’t know if other penguin species⁤ sleep in a similar fragmented fashion.

Scientists have ⁢documented a few other animals with special sleeping adaptions. While flying, frigatebirds can sleep one⁢ half⁢ of their brain at a time, and northern elephant seals can nap for 10⁢ or 15 minutes at a time during deep dives,⁤ for example.

But chinstrap penguin ⁣microsleeps appear to be a new extreme, researchers ⁤say.

“Penguins live in a ⁢high-stress environment. They breed in crowded colonies, and all their predators are‌ there at the same time,” said⁢ Daniel Paranhos Zitterbart, who‍ studies penguins at ⁣the Woods Hole Oceanographic Institution in Massachusetts and was not involved in ⁤the study.

Microsleeping is ”an amazing adaptation” ‌to ‍enable near ‍constant‌ vigilance, he said.

The‍ Associated Press Health and Science Department‍ receives support from the Howard Hughes ⁣Medical Institute’s Science and ⁤Educational Media Group. The AP is ⁤solely responsible for all content.