Sleeping With One Eye Open
There’s an old saying that if you think you’re in danger, you might ought to sleep with one eye open.
Well it turns out that many kinds of birds do just that.
A group of scientists at Indiana State University studied mallard ducks to learn more about this trait. They filmed a row of ducks while they were sleeping. Sure enough they found that a good part of the time the ducks at the ends of the row kept the eye facing away from the group open, while the eye toward the other ducks closed in sleep. The ducks within the row were more likely to close both of their eyes to sleep.
The ducks at the ends of the line were actually controlling which side of the brain stayed awake, and which dozed. They were engaging in what scientists call single-hemisphere sleep. The eye controlled by the sleeping side of the brain closed, while the active side kept its eye open and on the lookout.
You can see how this is good for the group and for the lookout duck as well. The group gets the protection from having someone pulling guard duty, while the guard duck is at least able to get some rest.
睜一只眼睡覺(jué)
有個(gè)很老的說(shuō)法，如果你覺(jué)得自己處于危險(xiǎn)之中，你會(huì)睜著一只眼睡覺(jué)。
事實(shí)證明許多鳥(niǎo)類(lèi)確實(shí)如此。
印第安納州立大學(xué)的一群科學(xué)家通過(guò)研究野鴨，對(duì)它們這個(gè)習(xí)性有了更多的了解?？茖W(xué)家們?cè)邙喿觽兯X(jué)時(shí)進(jìn)行拍攝。果然，他們發(fā)現(xiàn)隊(duì)伍兩端的鴨子朝外的那只眼睛長(zhǎng)時(shí)間睜著，而朝向其它鴨子的那只眼睛閉著睡覺(jué)。在隊(duì)列中間的鴨子們則雙眼緊閉睡覺(jué)。
隊(duì)列兩端的鴨子實(shí)際上在控制哪邊的大腦保持清醒與休息。它們處于科學(xué)家們所稱(chēng)的單邊睡眠的狀態(tài)。被睡眠狀態(tài)大腦控制的眼睛閉上，而被運(yùn)轉(zhuǎn)狀態(tài)大腦控制的眼睛睜開(kāi)放哨。
這種習(xí)性對(duì)整個(gè)群體及放哨鴨子非常有益。鴨群通過(guò)一些鴨子放哨獲得保護(hù)，而同時(shí)放哨鴨子至少能得到一些休息。
