英语听力文摘 English Digest 539、为什么斑马身上有条纹？

 　　Why Do Zebras Have Stripes?

 

　　For many animals, camouflage¹ is an important part of survival. A leopard’s spotted² coat and a polar bear’s white fur help them blend into their respective environments. But a zebra’s bold stripes can’t help to disguise it in its natural habitat, the open plains of Africa.or can they?

 

　　Why Zebras Have Stripes? On this moment of science.

 

　　The zebra’s bold markings can also help to conceal³ it. In 1844, naturalist⁴ Francis Galton pointed⁵ out that stripes can help disguise zebras in the dim, grayish light of an African night. Fifty years later, an artist named Abbot Thayer suggested that stripes could help actually change the way a predator⁶ sees a zebra.

 

　　The zebra’s bold markings draw the viewer’s attention to the stripes themselves, not the shape of the animal. So when a predator looks at a zebra, it sees stripes first, and then the zebra. This split second of recognition gives the fleet-footed zebra a chance to escape.

 

　　To other zebras in the herd⁷, the flash of stripes they see when one zebra starts to flee from an approaching lion is a “follow me” signal. Like the white flash of a deer’s tail, it alerts the entire herd to danger. The approaching lion, on the other hand, often loses his initial target in the confusing mass of moving stripes.

 

　　Stripes also allow young zebras in search of a meal to identify their mothers. When mating, adult zebras use stripes to recognize members of their own species.

 

　　As one nineteenth century breeder discovered, a female zebra will object vehemently⁹ to mating with a male ass⁸. But when the rejected suitor was disguised with hand-painted stripes, the female zebra happily accepted him.

1 camouflage   

n./v.掩饰，伪装

参考例句：

• The white fur of the polar bear is a natural camouflage.北极熊身上的白色的浓密软毛是一种天然的伪装。
• The animal's markings provide effective camouflage.这种动物身上的斑纹是很有效的伪装。

2 spotted   

adj.有斑点的，斑纹的，弄污了的

参考例句：

• The milkman selected the spotted cows,from among a herd of two hundred.牛奶商从一群200头牛中选出有斑点的牛。
• Sam's shop stocks short spotted socks.山姆的商店屯积了有斑点的短袜。

3 conceal   

v.隐藏，隐瞒，隐蔽

参考例句：

• He had to conceal his identity to escape the police.为了躲避警方，他只好隐瞒身份。
• He could hardly conceal his joy at his departure.他几乎掩饰不住临行时的喜悦。

4 naturalist   

n.博物学家(尤指直接观察动植物者)

参考例句：

• He was a printer by trade and naturalist by avocation.他从事印刷业，同时是个博物学爱好者。
• The naturalist told us many stories about birds.博物学家给我们讲述了许多有关鸟儿的故事。

5 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

6 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

7 herd   

n.兽群，牧群；vt.使集中，把…赶在一起

参考例句：

• She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
• He had no opinions of his own but simply follow the herd.他从无主见，只是人云亦云。

8 ass   

n.驴；傻瓜，蠢笨的人

参考例句：

• He is not an ass as they make him.他不象大家猜想的那样笨。
• An ass endures his burden but not more than his burden.驴能负重但不能超过它能力所负担的。

9 vehemently   

adv. 热烈地

参考例句：

• He argued with his wife so vehemently that he talked himself hoarse. 他和妻子争论得很激烈，以致讲话的声音都嘶哑了。
• Both women vehemently deny the charges against them. 两名妇女都激烈地否认了对她们的指控。