媒体英语 Mysteries of elephant sleep revealed 科学家揭开大象的睡眠模式之谜
Play audio file 文字稿 一项研究表明，非洲野象是睡眠时间最短的哺乳动物。一组科学家在非洲南部国家博茨瓦纳追踪记录了两只大象在自然环境中的睡眠规律。在动物园中笼养的大象每天睡四到六个小时，然而生活在野外的大象只休息两个小时，大多在夜晚入睡。请听 Helen Briggs 的报道。
Scientists tracked two elephants roaming across Botswana to find out more about the animals' sleeping habits. Elephants in captivity sleep for four to six hours a day, but it's always been suspected this might be different in the wild.
In fact, in their natural surroundings, the elephants slept for only two hours, mainly at night. The elephants, both matriarchs of the herd, sometimes stayed awake for days at a time, and they travelled long distances, perhaps to escape lions or poachers. And they only went into rapid eye movement or 'dreaming sleep' every three or four days.
Sleep plays a big role in memory. It's a mystery why an animal known for its incredible memory powers can survive on power naps alone.
词汇表 roaming 漫步，闲逛
in captivity （动物）被笼养
natural surroundings 自然环境
matriarchs （兽群中的）母系首领
herd 兽群，文中指象群
poachers 偷猎者
rapid eye movement 睡梦中眼部的快速运动，属于睡眠周期中的一个阶段，简称 REM
power naps （用短时间来恢复能量的）小睡
测验 请听报道并回答下列问题。
1. How many hours a day do elephants in captivity sleep?
2. Why did the elephants travel long distances, according to the text?
3. True or false? The two elephants are both female leaders of the herd.
4. Which word in the text means 'regularly repeated behaviours or practices'?
答案 1. How many hours a day do elephants in captivity sleep?
Elephants in captivity sleep for four to six hours a day.
2. Why did the elephants travel long distances, according to the text?
According to the text, the elephants travelled long distances, perhaps to escape lions or poachers.
3. True or false? The two elephants are both female leaders of the herd.
True. Both elephants are matriarchs of the herd, and the word 'matriarch' here means 'the most powerful female of a group of family'.
4. Which word in the text means 'regularly repeated behaviours or practices'?
Habits.