【英语时差8，16】天生爱游荡

 When you've been to the zoo have you noticed how some of the animals pace around a lot? In this Moment of Science Don and Ya?l discuss one explanation for this behavior.   D: Ya?l, I went to the zoo yesterday, and boy, the polar bear just kept pacing in circles, and don't even get me started about the lions. I guess they must really miss hunting, huh?

Y: You know, Don, that's what scientists used to think too, and so zoos worked hard to compensate¹ for this by focusing on stimulating² hunting behavior. But now scientists think the problem might be that the animals miss the freedom to roam.

D: That makes sense. After all, a polar bear's natural range is about the size of South Carolina.

Y: Right--and the typical zoo habitat is about one millionth of that.

D: No wonder some animals spend about a quarter of their time pacing. But how did scientists figure out that this was the problem?

Y: Well, researchers at Oxford³ studied the pacing behavior of thirty-five captive species using data from the over one thousand scientific articles published since the 1960s. And when they analyzed⁴ this data--which represented more than five hundred zoos worldwide--they determined⁵ that the deciding factor for pacing was range size. That also explains why stay-close-to-home species like snow leopards⁶ tend to thrive in zoos.

D: So what happens now?

Y: Well, one option is for zoos to build larger, more varied⁷ habitats, and switch enclosures periodically to simulate roaming. But a better option might be to phase animals like polar bears out of zoos, and focus instead on those animals that do well in captivity⁸. The problem is that this is a double-edged sword: these animals' natural habitats are increasingly threatened as well.

D: Depressing.

Y: No kidding.  

1 compensate   

vt.补偿，赔偿；酬报 vi.弥补；补偿；抵消

参考例句：

• She used her good looks to compensate her lack of intelligence. 她利用她漂亮的外表来弥补智力的不足。
• Nothing can compensate for the loss of one's health. 一个人失去了键康是不可弥补的。

2 stimulating   

adj.有启发性的，能激发人思考的

参考例句：

• shower gel containing plant extracts that have a stimulating effect on the skin 含有对皮肤有益的植物精华的沐浴凝胶
• This is a drug for stimulating nerves. 这是一种兴奋剂。

3 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

4 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

5 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

6 leopards   

n.豹( leopard的名词复数 )；本性难移

参考例句：

• Lions, tigers and leopards are all cats. 狮、虎和豹都是猫科动物。 来自《简明英汉词典》
• For example, airlines never ship leopards and canaries on the same flight. 例如，飞机上从来不会同时运送豹和金丝雀。 来自英语晨读30分（初三）

7 varied   

adj.多样的，多变化的

参考例句：

• The forms of art are many and varied.艺术的形式是多种多样的。
• The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。

8 captivity   

n.囚禁；被俘；束缚

参考例句：

• A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
• He was held in captivity for three years.他被囚禁叁年。