英语听力：自然百科 动物大迁徙

 Every fall, this herd¹ of pronghorn antelope² treks³ more than 100 miles from Grand Teton National Park to their winter habitat in the Upper Green River Valley of Wyoming. This phenomenal migration⁴, one of the longest in North America, has been taking place for the past 6,000 years.

 

As the snows develop and forage⁵ becomes unavailable, they migrate and move back, 100 to 150 miles back to the sagebrush basins of the Upper Green River basin where they can access forage through the winter.

 

Relying on information collected from VHS radio collars, researcher Hall Sawyer mapped this particular pronghorn migration route in 1998, with a half a million animals roaming the range. Wyoming is home to almost as many Pronghorn as people.

 

Within a hundred-mile radius⁶ of Casper, Wyoming, which is located right in the center of state, there’s more pronghorn than anywhere else in the world. Wyoming sustains most of the Pronghorn in North America. 

 

But part of the pronghorn habitat is becoming increasingly fragmented by human development. And some worry that crucial corridors are being severed⁷. Two men have an ambitious plan to find out which obstacles the pronghorn have to navigate⁸. Conservationist and adventurer Rick Ridgeway and photographer Joe Riis have set out to document "This Year's Migration".

 

Joe proposed to walk with those pronghorn on foot, nobody had ever done that before on foot, and more importantly document the migration in photographs, so that we could increase the awareness⁹ about the migration and the threats to the Pronghorn.

 

Joe Riis is one of National Geographic¹⁰ young explorers. He is a biologist and a wildlife photographer.

 

We walked, er, the distinct path that the pronghorn migrate in the fall and in the spring. We wanted to view the landscape through the eyes of the pronghorn and see the obstacles that the pronghorn see, see the beauty of the landscape as well as that human obstacles.

 

The duo quickly establishes that pronghorn are encountering some modern inconveniences along their ancient pathway.

 

In one day, we estimated a herd of about 800 animals moved, past us near Trappers Point, Wyoming. It's a natural bottleneck¹¹ that has been reduced by a subdivision. We watched the pronghorn dodge¹² cars and people along highway 191 and 352.

 

When they hit a migratory¹³ bottleneck, animals are confined to a narrow passageway. The squeeze can be caused by vegetation or human development. In the case of Trappers Point. It's both.

 

Every year, between 1,500 and 2,000 pronghorn cross through this bottleneck twice a year, once in the spring and once in the fall. Vehicle wildlife collisions are a problem all across the state, but they become particularly problematic during these migratory time periods when there is a lot of animals moving across the roads.

 

The most common barriers the animals face are roads and fences.

 

Fences pose a problem to the pronghorn because they are not evolved to jump over fences, they move underneath¹⁴ them, and if fences are woven wire, they can't move under, a lot of times they simply can't pass through.

 

In order to capture intimate photographs of the migration, Joe uses remote cameras.

 

Pronghorn Antelope can see 10 times better than we can. So if you move at all, they see you and they will stop and go the other way. You have to use remote camera systems that don't make any movement and take the pictures by themselves.

 

He positions the cameras in specific areas along the migration path often hiking miles to find the perfect spot. Joe’s ultimate goal is to get shots of the herd in motion, to capture the essence of this unique long distance journey.

 

I...I photograph this migration to inspire people to care about it. It's an incredible migration and people need/ to know about it. It’s happening right in the middle of the United States, it’s the second longest migration in the Western Hampshire.

 

Joe also documents the migration from the air. With the help of pilot Chris Boyer of LightHawk, an organization that provides free flights for conservationist. Aloft Joe can clearly see potential roadblocks.

 

During one of my aerial photography flights, I documented human development winthin the corridor. As more and more barriers are installed, that threat to this migration is increased.

 

The team discovers that oil and gas fields are also threatening the corridor. There’re already more than 8,000 wells on public lands, with plans to double that in the next decade.

 

These remarkable¹⁵ aerial photographs documented the changes since the 1980s.

 

In the last 100 years, the migration route has been threatened, by human development, by suburbs, and by ranchettes, and now by oil and gas development in the southern part of their range.

 

The team's extensive documentation of pronghorn corridor may help officials target where they need to act.

 

There're ways to protect wildlife corridors that are still compatible with human occupation in an area, and for example, a rancher could install fences that allow Pronghorn antelope, for example, to go under them without getting hung up on the barbed wire.

 

 

The team also hopes their efforts will spark an interest in protecting the animals.

 

The pronghorn migration corridor is 125 miles long and only a mile wide, it’s not gonna take that much to protect it.

 

If the human impact on this migration were to continue, then it's possible that the migration route might be cut off and if that were to happen there would be no mere¹⁶ pronghorn antelope in the Grand Tetons, and that would be tragic¹⁷ for everyone.

 

With commitment and planning, the pronghorn could continue their great annual migration just as they've done since the last Ice Age.

 

Sponsored by National Geographic mission programs, taking science and exploration into the new millennium¹⁸.

1 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。

2 antelope   

n.羚羊；羚羊皮

参考例句：

• Choosing the antelope shows that China wants a Green Olympics.选择藏羚羊表示中国需要绿色奥运。
• The tiger was dragging the antelope across the field.老虎拖着羚羊穿过原野。

3 treks   

n.远距离行走 ( trek的名词复数 )；长途跋涉，艰难的旅程（尤指在山区）v.艰苦跋涉，徒步旅行( trek的第三人称单数 )；（尤指在山中）远足，徒步旅行，游山玩水

参考例句：

• And visiting companies and completing job treks are becoming much more important in the job search. 参观公司、进行实地考察在找工作中变得重要得多。 来自互联网
• These range from treks around Mont an ascent of North Africa's highest mountain, Mount Toubkal. 参与者是徒步绕勃朗峰，然后攀登北非最高峰托布卡尔山。 来自互联网

4 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

5 forage   

n.(牛马的)饲料，粮草；v.搜寻，翻寻

参考例句：

• They were forced to forage for clothing and fuel.他们不得不去寻找衣服和燃料。
• Now the nutritive value of the forage is reduced.此时牧草的营养价值也下降了。

6 radius   

n.半径，半径范围；有效航程，范围，界限

参考例句：

• He has visited every shop within a radius of two miles.周围两英里以内的店铺他都去过。
• We are measuring the radius of the circle.我们正在测量圆的半径。

7 severed   

v.切断，断绝( sever的过去式和过去分词 )；断，裂

参考例句：

• The doctor said I'd severed a vessel in my leg. 医生说我割断了腿上的一根血管。 来自《简明英汉词典》
• We have severed diplomatic relations with that country. 我们与那个国家断绝了外交关系。 来自《简明英汉词典》

8 navigate   

v.航行，飞行；导航，领航

参考例句：

• He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
• Such boats can navigate on the Nile.这种船可以在尼罗河上航行。

9 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

10 geographic   

adj.地理学的，地理的

参考例句：

• 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

11 bottleneck   

n.瓶颈口，交通易阻的狭口；妨生产流程的一环

参考例句：

• The transportation bottleneck has blocked the movement of the cargo.运输的困难阻塞了货物的流通。
• China's strained railroads already become a bottleneck for the economy.中国紧张的铁路运输已经成为经济增长的瓶颈。

12 dodge   

v.闪开，躲开，避开；n.妙计，诡计

参考例句：

• A dodge behind a tree kept her from being run over.她向树后一闪，才没被车从身上辗过。
• The dodge was coopered by the police.诡计被警察粉碎了。

13 migratory   

n.候鸟，迁移

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。

14 underneath   

adj.在...下面，在...底下；adv.在下面

参考例句：

• Working underneath the car is always a messy job.在汽车底下工作是件脏活。
• She wore a coat with a dress underneath.她穿着一件大衣，里面套着一条连衣裙。

15 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

16 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

17 tragic   

adj.悲剧的，悲剧性的，悲惨的

参考例句：

• The effect of the pollution on the beaches is absolutely tragic.污染海滩后果可悲。
• Charles was a man doomed to tragic issues.查理是个注定不得善终的人。

18 millennium   

n.一千年，千禧年；太平盛世

参考例句：

• 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。