练习 | 科学美国人:Climate Change Fires Up Polar Bear Treadmill

练习 | 科学美国人:Climate Change Fires Up Polar Bear Treadmill

2.1分钟 3312 124wpm

科学美国人60秒:气候变化害苦了北极熊

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科学美国人60秒:Climate Change Fires Up Polar Bear Treadmill
气候变化害苦了北极熊
燕山大学 刘立军 宋葳 编写

◆TRANSCRIPT

Polar Bears spend most of their time roaming the sea ice in search of seals. And seals spend most of their time underneath that ice, avoiding the top predator. But climate change is giving polar bears additional challenges in their searches for food.

“Sea ice is now drifting faster.” George Durner is a research zoologist with the United States Geological Survey Polar Bear Research Program. He and colleagues compared sea ice conditions from 1987-1998 with those from 1999 to 2013.

“And what we found was that ice drift at the locations used by polar bears increased 30% in the Beaufort sea and 37% in the Chukchi sea.” That's a problem because polar bears are homebodies - they prefer to stay in a specific range.

“Throughout their range, they seem to have a sense of place. And … here we have a situation where the general pattern of ice drift is westward, so to remain in your traditional range, it means you have to constantly be walking eastward to compensate for that westward drift.”

The result: a large-scale polar bear treadmill. And all that walking requires extra fuel. On average, a single bear eats between 31 and 33 seals per year. But the metabolic consequence of the treadmill effect means they have to eat on average one to three more. The study is in the journal Global Change Biology.

And not only is the ice drifting faster - it's also melting more, giving the bears less of the platform they use to pursue their prey. So they need more seals but have a tougher time tracking them. All of which puts polar bears on a slippery slope.

Adapted from气候变化害苦了北极熊

◆VOCABULARY
1. predator n. an animal that kills and eats other animals 捕食性动物。例如:the relationship between predator and prey捕食性动物与猎物之间的关系

2. compensate v. compensate (for sth.) to provide sth. good to balance or reduce the bad effects of damage, loss, etc. 补偿;弥补。 make up for 例如:Nothing can compensate for the loss of a loved one. 失去心爱的人是无法补偿的。

3. metabolic adj. 新陈代谢的;代谢作用的 Metabolic means relating to a person's or animal's metabolism.

4. metabolism n. (biology 生) the chemical processes in living things that change food, etc. into energy and materials for growth 新陈代谢。例如:The body's metabolism is slowed down by extreme cold. 严寒可以使身体新陈代谢的速度下降。

5. prey n. an animal, a bird, etc. that is hunted, killed and eaten by another 猎物。例如:The lion will often stalk its prey for hours. 狮子经常悄然跟踪猎物达几个小时。

◆QUESTIONS
Read the table. Then listen to the news and complete the table.

WHAT

 

But _____________________ is giving polar bears additional challenges in their searches for food.

WHY

REASON 1

“ ________________ is now drifting faster.” George Durner is a research zoologist with the United States Geological Survey Polar Bear Research Program. He and colleagues compared ___________from 1987-1998 with those from 1999 to 2013.

 

REASON 2

“And what we found was that _________________ at the locations used by polar bears increased 30% in the Beaufort sea and 37% in the Chukchi sea.” That's a problem because polar bears are homebodies - they prefer to _____________________________.

 

REASON 3

“Throughout their range, they seem to have a sense of place. And … here we have a situation where the general pattern of ice drift is westward, so to remain in your traditional range, it means you have to constantly be ______________________________ to compensate for that _______________________.”

RESULT

 

A large-scale polar bear ________________. And all that walking requires _____________. On average, a single bear eats between 31 and 33 seals per year. But the metabolic consequence of the treadmill effect means they have to eat on average ________________. The study is in the journal Global Change Biology.

 

 

And not only is the _____________ - it's also ________________, giving the bears less of the platform they use to __________________. So they need more __________ but have a tougher time tracking them. All of which puts polar bears on _________________________.



◆KEY

1. climate change
2. Sea ice
3. sea ice conditions
4. ice drift
5. stay in a specific range
6. walking eastward
7. westward drift
8. treadmill
9. extra fuel
10. one to three more
11. ice drifting faster
12. melting more
13. pursue their prey
14. seals
15. a slippery slope
  • 时长:2.1分钟
  • 语速:124wpm
  • 来源:刘立军、宋葳 2017-09-25