考满分 toefl

1 .<-NARRATOR:-> Listen to part of a lecture in an environmental science class.

旁白：听一段环境科学课堂的讲座。

1 .<-FEMALE PROFESSOR:->Now, we've been talking about the loss of animal habitat from housing developments, um..., growing cities - small habitat losses.

教授：我们一直在讨论由住房建设和，呃……城市发展导致的动物栖息地的减少--小型栖息地的损失。

2 .But today I wanna begin talking about what happens when habitat is reduced across a large area.

今天我想先聊聊大型栖息地衰减时发生了什么。

3 .There are, of course, animal species that require large areas of habitat, and some migrate over very long distances.

当然，动物有需要大型栖息地的物种，也有迁徙的物种。

4 .So what's the impact of habitat loss on those animals - animals that need large areas of habitat?

那么，栖息地的缩减对需要大型栖息地的物种有什么影响呢？

1 .Well, I'll use the humming birds as an example.

我举一个蜂鸟的例子。

2 .Now you know a humming bird is amazingly small, but even though it's really tiny, it migrates over very long distances, travels up and down the western hemisphere - the Americas, back and forth between where it breeds in the summer and the warmer climates where it spends the winter.

大家都知道蜂鸟体形超小，但尽管它很小，它迁徙时得飞到很远的地方，南北横跨西半球——美洲，在夏季繁殖的地方和冬季有着温暖气候过冬的地方来回往返。

3 .So we would say that this whole area over which it migrates is its habitat because on this long-distance journey, it needs to come down to feed and sleep every so often, right?

这样你会说它们迁徙跨越的这片土地就是它们的栖息地因为在它们长途迁移的过程中它们需要时不时停下来进食和休息，是吗？

1 .Well, the humming bird beats its wings - get this - about 3 thousand times per minute.

蜂鸟扇动着翅膀——明白不——大约每分钟3 千次。

2 .So you think, wow, it must need a lot of energy, a lot of food, right?

所以，想想，哇，它们得需要很多能量，很多食物，对吧？

3 .Well, it does. It drinks a lot of nectar from flowers and feeds on some insects, but it's energy-efficient too.

是的，确实这样。它们得喝很多花蜜吃昆虫，其实它们也很节能的。

4 .You can't say it isn't. I mean, as it flies all the way across the Gulf of Mexico, it uses up almost none of its body fat.

这一点你得承认。我是说，当它们飞过墨西哥湾时，它们并没有耗尽身体的脂肪。

5 .But that doesn't mean it doesn't need to eat.

但这并不意味着它们不需要进食。

1 .So humming birds have to rely on plants in their natural habitat.

所以自然栖息地对蜂鸟来说植物是必须有的。

2 .And it goes without saying, but, well, the opposite is true as well, plants depend on humming birds too.

这是不言而喻的，但反过来也有道理，植物也依赖蜂鸟。

3 .There are some flowers that can only be pollinated by the humming birds.

一些花只靠蜂鸟来授粉。

4 .Without its stopping to feed and spreading pollen from flower to flower, these plants would cease to exist.

如果蜂鸟不停下来觅食或传播花粉，这些植物就不复存在。

1 .But the problem, well, as natural habitat along these migration routes is developed by humans for housing or agriculture or cleared for raising cattle, for instance, there is less food available for migrating humming birds.

但是，随着人类在蜂鸟迁徙路线上的自然栖息地进行开发，例如，扩建住房或是耕作或是放牧，蜂鸟在迁徙时能找到的食物就更少了。

2 .Their nesting sites are affected too, the same, by the same sorts of human activities.

它们的筑巢区也受到同样的人类活动的影响。

3 .And all of these activities pose a real threat to the humming bird population.

人类所有的这些活动对蜂鸟种群的繁殖造成真正的威胁。

1 .So to help them survive, we need to preserve their habitats.

要帮助它们生存，人类需要保护它们的栖息地。

2 .And one of the concrete ways people have been doing this is by cleaning up polluted habitat areas and then replanting flowers, um, replanting native flowers that humming birds feed on.

人们一直以来采取的保护蜂鸟栖息地的具体措施之一是清理受到污染的栖息地然后重新种植蜂鸟赖以生存的花草。

1 .Promoting ecological tourism is another way to help save their habitat.

推广生态旅游是保护它们栖息地的另外一种方式。

2 .As the number of visitors, eco-tourists who come to humming bird habitats to watch the birds, the more the number of visitors grows, the more local businesses profit.

随着游客数量的增加，这些生态旅游者来蜂鸟栖息地看鸟，游客的数量越多，当地的旅游景点收益越大。

3 .So ecological tourism can bring financial rewards, all the more reason to value these beautiful little creatures in their habitat, right?

这样看来生态旅游能带来经济回报，小巧漂亮的蜂鸟将更加得到重视，对吧？

1 .But to understand more about how to protect and support humming birds the best we can, we've got to learn more about their breeding, nesting sites and migration routes, and also about the natural habitats we find there.

但是要想更好地了解如何才能做到最大地保护蜂鸟，我们必须了解它们的繁殖，筑巢和迁徙路线，也需要了解沿途的自然栖息地。

2 .That should help us determine how to prevent further decline in the population.

这样能帮助我们决定如何防止蜂鸟数量进一步的减少。

1 .A good research method, a good way to learn more, is by running a banding study.

电子条带捆绑研究是对蜂鸟进一步了解的不错方式。

2 .Banding the birds allows us to track them over their lifetime. It's a practice that's been used by researchers for years.

条带绑定有助于我们对蜂鸟一生进行跟踪。多年来，研究人员一直在沿用这样的做法。

3 .In fact, most of what we've known about humming birds comes from banding studies, where we capture a humming bird and make sure all the information about it, like its weight and age and length, are all recorded, put into international, an international information database.

其实，人类对蜂鸟的了解绝大多数来源于（条带）捆绑研究，它提供蜂鸟确切的落脚点和其他的信息，如它的体重和年龄和寿命，都记录在案，然后输入一国际信息数据库。

4 .And then we place an extremely lightweight band on one of its legs, well, what looks like a leg, although technically it's considered part of the bird's foot.

我们将一个极为轻巧的电子条带绑在蜂鸟的一条腿上，嗯，看起来像一条腿，尽管严格地说它应该是依附在鸟脚上的。

5 .Anyway, these bands are perfectly safe, and some humming birds have worn them for years with no evidence of any problems.

不管怎么说，这些条带绝对安全，一些蜂鸟带着它好几年一点问题都没有。

6 .The band is labeled with a tracking number, oh, and there is a phone number on the band for people to call for free, to report a banded bird they've found or recaptured.

条带上标有追踪号码，哦，上面还有一个人们可以免费拨打的电话号码，用来了解该鸟被发现或被抓的情况。

1 .So when a banded bird is recaptured and reported, we learn about its migration route, its growth, and how long it has been alive, its life span.

当被绑定的蜂鸟被逮住并有人（通过绑定的电话号码）告知，我们就知道它的迁徙路线，它的成长和它活了多久，它的寿命。

2 .One recaptured bird had been banded almost 12 years earlier - she is one of the oldest humming birds on record.

一只再次被逮住的蜂鸟曾于12 年前被绑上电子条带——她是记录在案的最老的蜂鸟之一。

1 .Another interesting thing we've learned is that some humming birds, um, they no longer use a certain route.

我们了解到的另一个有意思的事是有些蜂鸟在迁徙时“不走寻常路”。

2 .They travel by a different route to reach their destination.

它们另辟蹊径飞到目的地。

3 .And findings like these have been of interest to biologists and environmental scientists in a number of countries who are trying to understand the complexities of how changes in a habitat affect the species in it, species like the humming birds.

这样的发现对致力于了解栖息地影响生活在其中的物种变化的复杂性的生物学家和环境科学家们来说一直兴趣盎然。