Part I
Professor: Now, we've been talking about the loss of animal habitat from housing developments, uh..., growing cities – small habitat losses. But today I wanna begin talking about what happens when habitat is reduced across a large area. There are, of course, animal species that require large areas of habitat, and some migrate over very long distances. So what's the impact of habitat loss on those animals – animals that need large areas of habitat? Well, I'll use the hummingbirds as an example.
Now you know a hummingbird 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. 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?
但是今天我想开始谈一下，当栖息地大范围减少时会发生什么。
所以我们可以说它迁徙的整个区域都是它的栖息地，因为在这样的长途旅行中，它不时地需要下来吃饭和睡觉，对吧？
1. migrate|maɪˈgreɪt|
verb. (of birds, animals, etc.) to move from one part of the world to another according to the season （随季节变化）迁徙
E.g.: Swallows migrate south in winter.
燕子在冬天迁徙到南方。
2. up and down
in one direction and then in the opposite direction 来回；往复
E.g.: She was pacing up and down in front of her desk.
她在办公桌前踱来踱去。
3. hemisphere|ˈhemɪsfɪə(r)|
noun. one half of the earth, especially the half above or below the equator （地球的）半球；（尤指）北半球，南半球
E.g.: the northern/southern hemisphere
北 / 南半球
4. back and forth
from one place to another and back again repeatedly 反复来回
E.g.: ferries sailing back and forth between the islands
往返于岛屿之间的渡船
5. every so often
sometimes but not often : from time to time不时，有时，偶尔
E.g.: Every so often she'd come in to check on him.
有时候她会过来看他。
Part II
Well, the hummingbird beats its wings – get this – about 3 thousand times per minute. So you think, wow, it must need a lot of energy, a lot of food, right? Well, it does. It drinks a lot of nectar from flowers and feeds on some insects, but it's energy efficient too. You can't say it isn't. I mean, as it flies all the way across the Gulf of Mexico, it uses up none of its body fat.
But that doesn't mean it doesn't need to eat. So hummingbirds have to rely on plants in their natural habitat. And it goes without saying, but, well... the opposite is true as well, plants depend on hummingbirds too. There are some flowers that can only be pollinated by the hummingbird. Without it stopping to feed and spreading pollen from flower to flower, these plants would cease to exist.
它从花中喝大量花蜜并以一些昆虫为食，但它能量效率很高，你不能说它不高，我的意思是当它一路飞越整个墨西哥湾时，它没有消耗任何自己的身体脂肪。
如果它不停下来，从一朵花飞到另一朵花中进食和传播花粉，那么这些植物将不复存在。
1. get|get|
verb. to notice(someone or something) 看（或听）到；注意到；意识到
E.g.:She showed up at the party in—get this —a $3,000 designer dress!
她出现在趴体上，你要知道，穿了一件3000刀的名牌裙子！
2. nectar |ˈnektə(r)|
noun. a sweet liquid that is produced by flowers and collected by bees for making honey 花蜜
E.g.: (figurative)On such a hot day, even water was nectar (= very good) .
这么热的天，清水都是甘露。
3. go without saying
to be very obvious or easy to predict 不用说；显而易见
E.g.: Of course I'll help you. That goes without saying.
我当然会帮你。这还用说吗？
4. pollinate |ˈpɒləneɪt|
verb. to put pollen into a flower or plant so that it produces seeds 授粉；传粉
E.g.: flowers pollinated by bees/the wind
由蜜蜂 / 风传粉的花卉
5. cease |si:s|
verb. (formal) to stop happening or existing; to stop sth from happening or existing （使）停止，终止，结束
E.g.: Welfare payments cease as soon as an individual starts a job.
一旦就业，即停发福利救济。
Part III
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 hummingbirds. Their nesting sites are affected too, the same by the same sorts of human activities. And all of these activities pose a real threat to the hummingbird population. So to help them survive, we need to preserve their habitats.
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 hummingbirds feed on. Promoting ecological tourism is another way to help save their habitat. As the number of visitors, eco-tourists who come to hummingbird habitats to watch the birds, the more the number of visitors grows, the more local businesses' profit, so ecological tourism can bring financial rewards, all the more reason to value these beautiful little creatures in their habitat, right?
但问题是，由于这些迁徙路线沿线的自然栖息地被人类开发利用，比方说用于住房开发、农业开发，或者被清除了用来养牛，迁徙的蜂鸟可获取的食物就变少了。
一直以来，人们用于保护栖息地的一个具体做法是清理受到污染的栖息地，然后重新种植花卉，嗯，重新种植那些蜂鸟赖以为食的本土花卉。
1. nest |nest|
verb. to make and use a nest 筑巢；巢居
E.g.: Thousands of seabirds are nesting on the cliffs.
成千上万的海鸟在悬崖上筑巢。
2. pose |pəʊz|
verb. to create a threat, problem, etc. that has to be dealt with 造成（威胁、问题等）；引起；产生
E.g.: The task poses no special problems.
这项任务不会造成特别的问题。
3. concrete|ˈkɒŋkri:t|
adj. based on facts, not on ideas or guesses 确实的，具体的（而非想象或猜测的）
E.g.: It is easier to think in concrete terms rather than in the abstract.
结合具体的事物来思考要比抽象思考容易些。
4. promote |prəˈməʊt|
verb. to help sth to happen or develop 促进；推动
E.g.: You don't have to sacrifice environmental protection to promote economic growth.
不必为了促进经济增长而牺牲环境保护。
Part IV
But to understand more about how to protect and support the hummingbirds 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. That should help us determine how to prevent further decline in the population. A good research method, a good way to learn more, is by running a banding study.
Banding the birds allows us to track them over their lifetime. It's a practice that's been used by researchers for years. In fact, most of what we known about hummingbirds comes from banding studies, where we capture a hummingbird and make sure all the information about it, like its weight and age and length, are all recorded and put into an international information database. 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.
但如果想要更多地了解如何才能尽我们所能去保护和支持蜂鸟，我们必须更多地去研究它们的繁殖、筑巢地点和迁徙路线，以及我们发现的自然栖息地。
然后我们在它的一条腿上放一条非常轻的带子，它看起来像一条腿，但是严格来讲它被认为是鸟脚的一部分。
1. run |rʌn|
verb. to do a test/check on sth （对…）进行（测试或检验）；实施
E.g.: The doctors decided to run some more tests on the blood samples.
医生决定对血样再进行一些化验。
2. band |bænd|
verb. to put a band of a different colour or material around sth 加彩条（或嵌条等）
E.g.: Many insects are banded black and yellow.
很多昆虫有黑色和黄色的条纹。
3. technically |ˈteknɪkli|
adv. according to the exact meaning, facts etc. 根据确切意义地；严格按照事实地
E.g.: Technically (speaking) , the two countries are still at war.
严格说来，这两国仍在交战。
Part V
Anyway, these bands are perfectly safe, and some hummingbirds have worn them for years with no evidence of any problems. 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. 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 lifespan. One recaptured bird had been banded almost 12 years earlier – she's one of the oldest humming birds on record.
Another interesting thing we've learned is that some humming birds, um, they no longer use a certain route. They travel by a different route to reach their destination. 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 hummingbirds.
许多国家的生物学家和环境科学家都对这样的发现很感兴趣，他们试图据此了解栖息地变化是如何影响其中物种的复杂性的，比如蜂鸟这个物种。
1. label |ˈleɪbl|
verb. to fix a label on sth or write information on sth 贴标签于；用标签标明
E.g.: We carefully labelled each item with the contents and the date.
我们仔细地把每件物品用标签标明成分和日期。
2. report |rɪˈpɔ:t|
verb. to give people information about sth that you have heard, seen, done, etc. 汇报；报告；通报
E.g.: The neighbours reported seeing him leave the building around noon.
邻居们反映说在中午时分看见他离开了大楼。
3. lifespan|ˈlaɪfspæn|
noun. the length of time that sth is likely to live, continue or function 寿命；可持续年限；有效期
E.g.: Worms have a lifespan of a few months.
蠕虫的寿命为几个月。
