英语听力:自然百科 濒临灭绝的鼠兔
时间:2019-01-22 作者:英语课 分类:自然百科2009年
Autumn in the Rocky Mountains, a time of change. Aspens turn golden and the bull elk 1, in the midst of their mating season, work hard to catch the eye and ears of the ladies. Up in the highest peaks, another call rings out. It's the pint-sized prince of the Alpine 2 tundra 3, a relative of the rabbit, known as the pika. Pikas are among the world's highest dwelling 4 animals, often choosing the most frigid 5 mountain tops to call home. Pikas, once common in mountain ranges around the world, are vanishing, even in protected places, like Rocky Mountain National Park. To investigate these disappearances 6, national geographic 7 grantee Rob Guralnick and his pika research team are making the trek 8 to the tundra. Throughout the summer months, the biologists will routinely canvass 9 sites where pika had been spotted 10 in the past, in order to determine how many are left.
We are losing a very characteristic Alpine denizen 11, something that a lot of people recognize and see when they got there, that's sort of now going missing on mountaintops. So the question becomes, you know, what's going on in the Rockies where that the rarest stronghold is in this, in this very rich area for pika habitat.
Today, the pikas are elusive 12. But, fortunately, they leave their telltale signs of their presence behind.
It's a great, a great connection of scat here.
Yeah, a little urine’s, urine station is white. You can see the white.
But each of these little peppercorn-like things, it's, it's a fresh pika. It's a pika scat, some fresh, some not.
Rob's team also finds plenty of miniature haystack, grass and flowers the animals lay out to dry.
Unlike most of the Alpine species, they don't shut down in the winter. Marmots, other mammals hibernate 13. Pikas don't hibernate. That's part of what they are doing when they hay is collect that vegetation for the winter so that they sustain themselves.
Back in the lab, the team analyzes 14 the pika data. The first result suggests that the pika is headed the way of many other small Alpine mammals. In a wider study, Rob mapped the temperature and historical distribution of many small Alpine mammals. He found that most of the species used to live at low elevations 15 across larger areas. Something is driving the mammals higher up the mountains. Rob looks to the climate for answers. As carbon dioxide and other greenhouse gas emissions 16 increase, temperatures around the global are climbing, even in the Rockies.
They have to really have a good little internal heater going, and a high metabolism 17 so that they can generate enough heat to stay warm in the winter. Then in turn, because they're generating so much heat, that's not something you can necessarily shut off in the summer. So, most of the time, Alpine stays pretty cool. In the summer, but if you get really hot streak 18 in the Alpine, the pikas are not gonna be able to thermoregulate or cool themselves down very easily, 'cause their metabolism is high.
When it gets too hot, the little pikas overheat and die. As the climate warms, some species have been moving to higher elevations to seek cooler weather, but the pikas already inhabit the highest point. There's nowhere left for them to go.
As well as being a loss of a great charismatic, wonderful taxon, it'd be that bellweather of further changes that are likely to be occurring not just the pikas, but to all organisms that live in the Alpine. And of course that's a real concern. We start losing ecosystems 19 and the services they provide to humans.
At least this year, Many pikas have been able to beat the heat. And next spring, the call of the pika will ring out once again across the Alpine. Sponsored by National Geographic Mission Programs, taking science and exploration into the new millennium 20.
- I was close enough to the elk to hear its labored breathing.我离那头麋鹿非常近,能听见它吃力的呼吸声。
- The refuge contains the largest wintering population of elk in the world.这座庇护所有着世界上数量最大的冬季麋鹿群。
- Alpine flowers are abundant there.那里有很多高山地带的花。
- Its main attractions are alpine lakes and waterfalls .它以高山湖泊和瀑布群为主要特色。
- The arctic tundra is at the top of the world around the North Pole.北极冻原是指北极点周边的地区,是世界最高的地方。
- There is a large amount of methane gas under the Siberian tundra.西伯利亚的冻土地带之下有大量的甲烷气体。
- Those two men are dwelling with us.那两个人跟我们住在一起。
- He occupies a three-story dwelling place on the Park Street.他在派克街上有一幢3层楼的寓所。
- The water was too frigid to allow him to remain submerged for long.水冰冷彻骨,他在下面呆不了太长时间。
- She returned his smile with a frigid glance.对他的微笑她报以冷冷的一瞥。
- Most disappearances are the result of the terrorist activity. 大多数的失踪案都是恐怖分子造成的。 来自辞典例句
- The espionage, the betrayals, the arrests, the tortures, the executions, the disappearances will never cease. 间谍活动、叛党卖国、逮捕拷打、处决灭迹,这种事情永远不会完。 来自英汉文学
- The city's success owes much to its geographic position. 这座城市的成功很大程度上归功于它的地理位置。 来自《简明英汉词典》
- Environmental problems pay no heed to these geographic lines. 环境问题并不理会这些地理界限。 来自英汉非文学 - 环境法 - 环境法
- We often go pony-trek in the summer.夏季我们经常骑马旅行。
- It took us the whole day to trek across the rocky terrain.我们花了一整天的时间艰难地穿过那片遍布岩石的地带。
- Mr. Airey Neave volunteered to set up an organisation to canvass votes.艾雷·尼夫先生自告奋勇建立了一个拉票组织。
- I will canvass the floors before I start painting the walls.开始粉刷墙壁之前,我会详细检查地板。
- 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。
- In this country children of denizen go to school free.在这个国家外籍居民的孩子免费上学。
- His greatest danger now lie in the unknown denizen of the water.现在他最大的危险是未知的水中居住者。
- Try to catch the elusive charm of the original in translation.翻译时设法把握住原文中难以捉摸的风韵。
- Interpol have searched all the corners of the earth for the elusive hijackers.国际刑警组织已在世界各地搜查在逃的飞机劫持者。
- Bears often hibernate in caves.熊常在山洞里冬眠。
- Some warm-blooded animals do not need to hibernate.一些温血动物不需要冬眠。
- This approach analyzes management by studying experience usually through cases. 这个学派通常从实例获得经验,用以分析管理。 来自辞典例句
- The econometrician analyzes statistical data. 经济计量学者要分析统计材料。 来自辞典例句
- Weight of the crust changes as elevations are eroded and materials are deposited elsewhere. 当高地受到侵蚀,物质沉积到别的地方时,地壳的重量就改变。
- All deck elevations are on the top of structural beams. 所有甲板标高线均指结构梁顶线。
- Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
- Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。
- After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食,卡罗尔的新陈代谢完全紊乱了。
- All living matter undergoes a process of metabolism.生物都有新陈代谢。
- The Indians used to streak their faces with paint.印第安人过去常用颜料在脸上涂条纹。
- Why did you streak the tree?你为什么在树上刻条纹?
- There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
- Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样,从雨林到半荒漠等不一而足。 来自辞典例句
- The whole world was counting down to the new millennium.全世界都在倒计时迎接新千年的到来。
- We waited as the clock ticked away the last few seconds of the old millennium.我们静候着时钟滴答走过千年的最后几秒钟。