Chinstrap penguins get their name from the thin black line under their chins, which looks like a strap (带子) holding on a black hat or helmet. Like other penguins, they spend much of their time in the water, catching fish to eat. But when the time comes to raise their young, they return to land.
▲ The eggs are often laid in nests made of small rocks to keep the eggs from freezing. One parent takes care of the nest for long periods of time, while the other parent hunts for food. The parent must constantly keep a sharp lookout. Birds called brown skuas target the eggs and young penguins of careless parents. Other penguins in these crowded areas may take stones from the nest, putting the young in danger. But it’s hard to stay alert and protect a nest 24 hours a day. Getting a good night’s sleep could be deadly for the young.
Scientist Won Young Lee noticed that the chinstrap parents were constantly blinking (眨) their eyes. He wondered if more was happening than just blinking. So he and a group of scientists attached tiny electrical devices to the heads of 14 chinstrap penguins. The devices allowed the scientists to measure the brain activity of the penguins. At the same time, the scientists recorded the birds on video. Eleven days of studying the penguins revealed that the tired parents were actually sleeping in short bursts — about four seconds at a time. By doing this thousands of times daily, they get about 11 hours of sleep a day.
It’s not clear if the microsleeps allow the penguins to actually feel rested, or if it’s just enough to allow them to keep going. But the penguins are able to keep up the pattern for weeks, which allows them to protect their nests, eggs, and babies. The scientists don’t know yet if the penguins sleep this way at other times of the year, or only when they’re raising their young. They also don’t know if other kinds of penguins have similar sleeping habits. But scientists who study how animals sleep say that this is an important study, and especially impressive because it was carried out in the penguins’ natural environment.
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