当前位置: 首页 > 雅思阅读原文翻译 > 正文

剑桥雅思11Test3Passage2阅读原文翻译 Great Migrations 伟大的迁徙 剑桥雅思11 […]

剑桥雅思11Test3Passage2阅读原文翻译 Great Migrations 伟大的迁徙



雅思真题阅读词汇 剑桥雅思11 test 3 passage 2 动物迁徙Great Migrations

剑桥雅思11Test3Passage2阅读答案解析 Great Migrations 伟大的迁徙

剑桥雅思11 Test3 Passage2阅读原文翻译


Animal migration, however it is defined, is far more than just the movement of animals. It can loosely be described as travel that takes place at regular intervals – often in an annual cycle – that may involve many members of a species, and is rewarded only after a long journey. It suggests inherited instinct. The biologist Hugh Dingle has identified five characteristics that apply, in varying degrees and combinations, to all migrations. They are prolonged movements that carry animals outside familiar habitats; they tend to be linear, not zigzaggy; they involve special behaviours concerning preparation (such as overfeeding) and arrival; they demand special allocations of energy. And one more: migrating animals maintain an intense attentiveness to the greater mission, which keeps them undistracted by temptations and undeterred by challenges that would turn other animals aside.

无论如何定义动物迁徙,它都不仅仅是动物的移动而已。它可以大致被描述为按照规律的间隔(通常以一年为周期)所进行的旅行。这通常涉及某一种群中的大部分成员,并且只有在漫长的旅程之后才能得到奖励。这种行为显示出它们的遗传本能。生物学家Hugh Dingle总结出5个在不同程度上或者按照不同组合适用于所有迁徙的特点。它们是漫长的移动,将动物带出熟悉的栖息地;它们通常是线性的,而非蜿蜒曲折的;它们涉及到与准备(如过量饮食)和到达相关的特殊行为;它们需要独特的能量分配。此外还有一点,迁徙中的动物对这一伟大的任务高度专注。这让它们不会被诱惑所干扰,面对让其他动物止步不前的挑战不屈不挠。


An arctic tern, on its 20,000 km flight from the extreme south of South America to the Arctic circle, will take no notice of a nice smelly herring offered from a bird-watcher’s boat along the way. While local gulls will dive voraciously for such handouts, the tern flies on. Why? The arctic tern resists distraction because it is driven at that moment by an instinctive sense of something we humans find admirable: larger purpose. In other words, it is determined to reach its destination. The bird senses that it can eat, rest and mate later. Right now it is totally focused on the journey; its undivided intent is arrival. Reaching some gravelly coastline in the Arctic, upon which other arctic terns have converged, will serve its larger purpose as shaped by evolution: finding a place, a time, and a set of circumstances in which it can successfully hatch and rear offspring.



But migration is a complex issue, and biologists define it differently, depending in part on what sorts of animals they study. Joel Berger, of the University of Montana, who works on the American pronghorn and other large terrestrial mammals, prefers what he calls a simple, practical definition suited to his beasts: ‘movements from a seasonal home area away to another home area and back again’. Generally the reason for such seasonal back-and-forth movement is to seek resources that aren’t available within a single area year-round.

但是,迁徙是一个复杂的问题,根据生物学家所研究的动物种类不同,他们对它的定义也各有不同。蒙大拿大学、研究美国叉角羚和其他大型陆生哺乳动物的Joel Berger,倾向于使用一个适用于他所研究的动物类型的,简单实用的定义:“从一个季节性的栖息地离开,到另外一个栖息地去,并再次返回的过程”。大体来说,这种季节性往返移动的原因是为了寻找在某个单一区域并非全年存在的资源。


But daily vertical movements by zooplankton in the ocean – upward by night to seek food, downward by day to escape predators – can also be considered migrationSo can the movement of aphids when, having depleted the young leaves on one food plant, their offspring then fly onward to a different host plant, with no one aphid ever returning to where it started.



Dingle is an evolutionary biologist who studies insects. His definition is more intricate than Berger’s, citing those five features that distinguish migration from other forms of movement. They allow for the fact that, for example, aphids will become sensitive to blue light (from the sky) when it’s time for takeoff on their big journey, and sensitive to yellow light (reflected from tender young leaves) when it’s appropriate to land. Birds will fatten themselves with heavy feeding in advance of a long migrational flight. The value of his definition, Dingle argues, is that it focuses attention on what the phenomenon of wildebeest migration shares with the phenomenon of the aphids, and therefore helps guide researchers towards understanding how evolution has produced them all.



Human behaviour, however, is having a detrimental impact on animal migration. The pronghorn, which resembles an antelope, though they are unrelated, is the fastest land mammal of the New World. One population, which spends the summer in the mountainous Grand Teton National Park of the western USA, follows a narrow route from its summer range in the mountains, across a river, and down onto the plains. Here they wait out the frozen months, feeding mainly on sagebrush blown clear of snow. These pronghorn are notable for the invariance of their migration route and the severity of its constriction at three bottlenecks. If they can’t pass through each of the three during their spring migration, they can’t reach their bounty of summer grazing; if they can’t pass through again in autumn, escaping south onto those windblown plains, they are likely to die trying to overwinter in the deep snow. Pronghorn, dependent on distance vision and speed to keep safe from predators, traverse high, open shoulders of land, where they can see and run. At one of the bottlenecks, forested hills rise to form a V, leaving a corridor of open ground only about 150 metres wide, filled with private homes. Increasing development is leading toward a crisis for the pronghorn, threatening to choke off their passageway.



Conservation scientists, along with some biologists and land managers within the USA’s National Park Service and other agencies, are now working to preserve migrational behaviours, not just species and habitats. A National Forest has recognised the path of the pronghorn, much of which passes across its land, as a protected migration corridor. But neither the Forest Service nor the Park Service can control what happens on private land at a bottleneckAnd with certain other migrating species, the challenge is complicated further – by vastly greater distances traversed, more jurisdictions, more borders, more dangers along the way. We will require wisdom and resoluteness to ensure that migrating species can continue their journeying a while longer.


剑桥雅思11Test3Passage1阅读原文翻译 The story of silk 丝绸的故事

剑桥雅思11Test3Passage3阅读原文翻译 Preface to How the other half thinks

本文固定链接: http://www.laokaoya.com/29999.html | 老烤鸭雅思-专注雅思备考

剑桥雅思11Test3Passage2阅读原文翻译 Great Migrations:等您坐沙发呢!


error: Alert: Content is protected !!