手机APP下载

您现在的位置: 首页 > 托福 > 托福听力 > 托福听力真题听写 > 正文

托福TPO-08 Lecture 1

来源:可可英语 编辑:mike   VIP免费外教试听课 |  可可官方微信:ikekenet
 下载MP3到电脑  批量下载MP3和LRC到手机
加载中..

Pro:Well, last time we talked about passive habitat selection,

教授:上一次,我们谈到了消极栖息地的选择,
like plants for example, they don't make active choices about where to grow.
比方说植物都不会对于它们生长地点做积极地选择。
They are dispersed by some other agent, like the wind.
它们被一些风之类的原因分散。
And if the seeds land in a suitable habitat, they do well and reproduce.
而如果种子在一片合适的栖息地着陆,它们会生长的不错,并且繁殖。
With active habitat's selection, an organism is able to physically select where to live and breed.
但是对于积极的栖息地选择,生物就会在生理意义上选择它们生长繁殖的地方。
And because the animal breeding habitat is so important, we expect animal species to develop preferences for particular types of habitats. Places where their offspring have the best chance for survival.
并且因为动物的栖息地是如此的重要,以至于我们认为动物物种倾向于选择使它们的后代有最好生存几率的地方。
So let's look at the effect the preference can have by looking at some examples,
那么,让我们通过几个例子来看一下这些偏好的影响,
but first let's recap.
但是首先我们复习一下。
What do we mean by habitat? Frank?
弗兰克,栖息地是什么意思?
Stu:Well, it's basically the place or environment where an organism normally lives and grows.
学生:它是生物通常生长生活的地方或者环境。
Pro:Right, and as we discussed, there are some key elements that habitat must contain, food obviously, water, and is got have a right climate and basics for physical protection.
教授:是的,正如我们所讨论的,一处栖息地必须包含有一些关键因素。显然,食物、水,然后还有合适的气候,以及自我保护的空间。
And we were sound how important habitat selection is when we look at the habitat were some of the factors are removed, perhaps through habitats' destruction.
我们可以看到当这些因素被移除的时候,这些栖息地的选择是多么的重要。
I just read about a short bird, the plover.
我刚刚读了一些关于一种叫珩科鸟的资料。
The plover lives by the ocean and feeds on small shellfish insects in plants.
珩科鸟生活在海边,以小贝壳、昆虫还有植物为食。
It blends in with the sand, so it well camouflage from predator birds above.
它们会躲在沙子里,与沙子混为一体,所以可以很好的躲避捕食鸟类。
But it lags eggs in shallow depressions in the sand with very little protection around them.
但是,它们总是在几乎没有遮护的低洼地里面产蛋。
So if there are people or dogs on the beach, the eggs and fledglings in the nest are really vulnerable.
所以如果有人或者狗在沙滩上,在巢中的蛋和幼鸟会非常脆弱,很容易受到伤害。
Outing California weather has been a lot of human development by the ocean.
而在加州的海滩有很多的人工建筑。
The plovers are now is threaten species.
所以现在珩科鸟已经是一个濒危物种。
So conservation is tried to recreate a new habitat for them.
所以动物保护主义者们正在尝试着为它们建立一个新的栖息地。
They made artificial beaches and sun bars in area inaccessible to people and dogs.
他们做了一个人工的海滩以及防止人类和狗进入的沙洲。
And the plover population is up quite a bit in those places.
而在这些地方,珩科鸟的数量增加了不少。
Ok. That is an incidence where a habitat is made less suitable.
好了,这就是一个关于栖息地变的不适于居住的例子。
But now, what about the case where animal exhibits a clear choice between two suitable habitats in cases like that.
但是现在,如果两个栖息地都很合适,那么动物会表现出怎样的选择呢?
Dose the preference matter?
偏好会起到关键作用吗?
Let's look at the blue warbler.
让我们再来看看蓝莺。
The Blue warbler is a songbird that lives in the North America.
这是一种生活在北美的鸣鸟。
They clearly prefer hard wood forests with dense shrubs, bushes underneath the trees.
它们很显然的偏好于有着稠密的灌木丛阔叶树森林。
They actually nest in the shrubs, not the trees.
它们通常会在灌木丛中筑巢,而不是在树上。
So they pretty close to the ground,
所以,它们倾向于接近地面,
but these warblers also nest in the forests that have low shrub density.
但是这些蓝莺也会在有着稀疏灌木丛的森林里面筑巢。
It is usually the younger warblers that next to the area because prefers spots where a lot of shrubs are taken by order more dominant birds.
通常,年轻的蓝莺将会在这些地方,因为更好的地方已经被成年蓝莺所占据。
And the choice of habitat seems to affect the reproductive success.
并且这些栖息地的选择貌似将会影响繁殖的成功与否。
Because the order and more experienced birds who nest in the high density shrub areas have significantly more offspring than those in low density areas,
因为,更加成熟,更加有经验的鸟将会在高度稠密的灌木丛中筑巢,相较至于在低密度灌木丛筑巢的鸟,它们明显会繁育更多的后代。
which suggests that the choice of where to nest does have impact on the number of chicks they have.
这也就表明了在哪里筑巢对于下一代的数量有着很大的影响。
But preferred environment doesn't always seem to correlate with greater reproductive success.
但是,偏好的环境并不总是与高繁殖率有关。
For example, In Europe, study has been done of blackcap warblers.
比如欧洲对于黑顶莺就曾进行过一些研究,
We just call them blackcaps.
我们把它们叫做黑顶。
Blackcaps can be found in two different environments.
这些黑顶被发现在两种不同的环境里面,
Their preferred habitat is forest that near the edge of streams.
它们偏好的环境是在溪流附近的森林里面。
However, blackcaps also live in pine woods away from water.
但是,黑顶也住在远离水源的松林中。
Study has been done on the reproductive success rate for birds in both areas,
在这两种地区都做了有关于繁殖成功率的研究。
and the result showed surprisingly that the reproductive success was essentially the same in both areas-the preferred and the second choice habitat. Well. Why?
结果很令人惊异的表明在这两种地方的繁殖率基本一致。为什么呢?
It turns out there were actually four times as many bird pairs or couples living in the stream edge habitat compared to the area away from the stream,
结果是,事实上,在溪流边缘的森林里面住着比远离溪流地区四倍多的鸟。
so this stream edge area had much denser population which meant more members of same species competing for the resources.
所以溪流附近的地区有着更加稠密的人口密度,也就意味着对于资源的竞争很激烈。
When into feed on same thing or build their nests in the same places, which lower the suitability of the prime habitat even though its their preferred habitat.
而竞争就降低了动物在这些主要栖息地的适应能力,尽管这是它们所偏好的地区。
So the results of the study suggests that when the number of the competitors in the prime habitat reaches a certain point, the second random habitat becomes just as successful as the prime habitat, just because there are fewer members of the same species living there.
所以研究结果显示当在主栖息地的竞争者数量达到一定的量时,第二选择的栖息地将会在和主栖息地一样能够的成功,仅仅是因为有相对较少的物种在那里生存。
So it looks like competition for resources is another important factor in determining if particular habitat is suitable.
所以相互争夺资源也是判断一个栖息地是否合适的重要影响因素。

重点单词   查看全部解释    
random ['rændəm]

想一想再看

adj. 随机的,随意的,任意的
adv. 随

 
prime [praim]

想一想再看

adj. 最初的,首要的,最好的,典型的
n.

联想记忆
factor ['fæktə]

想一想再看

n. 因素,因子
vt. 把 ... 因素包括

联想记忆
affect [ə'fekt]

想一想再看

vt. 影响,作用,感动

联想记忆
preference ['prefərəns]

想一想再看

n. 偏爱,优先,喜爱物

联想记忆
dose [dəus]

想一想再看

n. 剂量,一剂,一服
vt. 给 ... 服

 
essentially [i'senʃəli]

想一想再看

adv. 本质上,本来

 
reproduce [.ri:prə'dju:s]

想一想再看

v. 再生,复制,生殖

 
particular [pə'tikjulə]

想一想再看

adj. 特殊的,特别的,特定的,挑剔的
n.

联想记忆
artificial [.ɑ:ti'fiʃəl]

想一想再看

adj. 人造的,虚伪的,武断的

联想记忆

    阅读本文的人还阅读了:
  • 托福TPO-07 Lecture 4 2013-08-13
  • 托福TPO-08 Conversation 1 2013-08-14
  • 托福TPO-08 Lecture 2 2013-08-19
  • 托福TPO-08 Conversation 2 2013-08-20
  • 托福TPO-08 Lecture 3 2013-08-21
  • 新东方托福网络课程:试听更多托福网络课程>>

    发布评论我来说2句

      可可英语官方微信(微信号:ikekenet)

      每天向大家推送短小精悍的英语学习资料.

      添加方式1.扫描上方可可官方微信二维码。
      添加方式2.搜索微信号ikekenet添加即可。