Every animal with a brain needs sleep — and even a few without a brain do, too. Humans sleep, birds sleep, whales sleep and even jellyfish sleep.Sleep is universal “even though it’s actually very risky,” said Paul-Antoine Libourel, a researcher at the Neuroscience Research Center of Lyon in France.When animals nod off, they’re most vulnerable to sneaky predators. But despite the risks, the need for sleep is so strong that no creature can skip it altogether, even when it’s highly inconvenient.AdvertisementAdvertisementAdvertisementAdvertisementAnimals that navigate extreme conditions and environments have evolved to sleep in extreme ways — for example, stealing seconds at a time during around-the-clock parenting, getting winks on the wing during long migrations and even dozing while swimming.For a long time, scientists could only make educated guesses about when wild animals were sleeping, observing when they lay still and closed their eyes. But in recent years, tiny trackers and helmets that measure brain waves — miniaturized versions of equipment in human sleep labs — have allowed researchers to glimpse for the first time the varied and sometimes spectacular ways that wild animals snooze.“We’re finding that sleep is really flexible in response to ecological demands,” said Niels Rattenborg, an animal sleep research specialist at the Max Planck Institute for Biological Intelligence in Germany.Call it the emerging science of “extreme sleep.”AdvertisementAdvertisementAdvertisementAdvertisementChinstrap penguins and their ‘microsleeps’Take chinstrap penguins in Antarctica that Libourel studies.These penguins mate for life and share parenting duties — with one bird babysitting the egg or tiny gray fluffy chick to keep it warm and safe while the other swims off to fish for a family meal. Then they switch roles — keeping up this nonstop labor for weeks.More in SciencePenguin parents face a common challenge: getting enough sleep while keeping a close eye on their newborns.They survive by taking thousands of catnaps a day — each averaging just 4 seconds long.These short “microsleeps,” as Korea Polar Research Institute biologist Won Young Lee calls them, appear to be enough to allow penguin parents to carry out their caregiving duties for weeks within their crowded, noisy colonies.AdvertisementAdvertisementAdvertisementAdvertisementWhen a clumsy neighbor passes by or predatory seabirds are near, the penguin parent blinks to alert attention and soon dozes off again, its chin nodding against its chest, like a drowsy driver.The naps add up. Each penguin sleeps for a total of 11 hours per day, as scientists found by measuring the brain activity of 14 adults over 11 days on Antarctica’s King George Island. …
