大学英语自学教程(上册) unit 19 动物濒危,谁来关心
大耳朵英语  http://www.bigear.cn  2010-01-05 16:23:41  【打印
19-A. Animals at Risk: Who Cares?

An animal species becomes extinct when it fails to produce enough young in each generation to keep pace with the death-rate. We can tell from fossil evidence in rocks that many living species have become extinct over the millions of years since life began. It is a natural process and extinction is the fate of any animal that has specialized too far to change when its environment changes, or has to compete with a better-adapted and more powerful animal. Because of remarkable technical developments during the past few centuries, man has destroyed or nearly destroyed some species by killing them at such a rate that they couldn't produce enough offspring, or by completely changing their natural environment at surprising speed.

A number of examples can be given of the way in which natural environments are being rapidly changed - Amazonia, for instance. There is every likelihood that many species of animals will be made extinct because of these and similar clearances of natural vegetation. Large numbers of animals have been hunted and killed for food. The North American buffalo is a case of the near-extinction of a species through hunting. Often the numbers are so great the hunters may not realize the danger. But even when the danger is widely publicized, the financial rewards for the hunters may be so great that they choose to ignore the threat to the species. Attitudes like this have led to hunters killing animals for furs, for ivory or merely for ornaments. A slight variation on this is when tourists hunt animals for trophies. Magnificent creatures such as lions and tigers have been hunted out of existence in some parts of the world. It is important to realize, though, that animals are sometimes killed out of fear. Big cats are killed in this way. And animals are sometimes killed out of a wish to reduce numbers to help the species to survive. The killing of the Canadian seals is claimed to be for this purpose, and the use of their skins for furs is only a by-product.

Many people are concerned about animals and wildlife conservation. One way to preserve species under threat of extinction - whatever the cause - is to remove them to zoos and parks and breed them there. There is always the chance that enough offspring will be born to return them one day to their natural environment - provided it still exists, and that hunters don't kill them again! Another method is to protect the animals in their natural environment by creating wildlife reserves and parks and using game wardens to look after them. But the parks are large, the wardens few and the determination of hunters very great. Early in 1980 wardens and hunters clashed in East Africa. The hunters were armed with modern weapons and several people were killed.

There is great pleasure in watching wildlife in natural or near-natural environments, and tourism can add to the income of countries. The animals are still resources - but in a very different form.

【课文译文】

动物濒危,谁来关心

当一种动物不能在每一代都繁殖出足够的后代而与其死亡率保持一致时,它就会逐渐灭绝了。我们可根据岩石里的化石得出结论:自生命开始数百万年以来,许多物种已经灭绝了。这是一个自然过程,任何一种过于特化而不能随环境改变而改变的动物,或者任何一种与适应性更强、更厉害的动物来竞争的动物,灭绝都是其必然的命运。由于近几个世纪技术的迅猛发展,人类大量捕杀动物以致其繁殖不出足够多的后代,或者以惊人的速度改变它们生存的自然环境,结果一些动物被毁灭或几乎被毁灭了。

很多例子都可以说明自然环境是如何迅速被改变的,亚马逊尼亚国家公园就是一个例子。很有可能,许多种动物将由于自然植物在这些或类似的地方被砍伐殆尽而濒于灭绝。大量的动物被捕杀用作食物。北美野牛就是一个因捕猎而近于灭绝的例子。

动物的数量常常很大,因而捕猎者可能意识不到它们存在灭绝的危险。但即使这种危险被广而告之,捕猎者为获取巨大经济利益,可能会无视动物的存亡。这种思想使猎人为获取毛皮、象牙或仅仅为了做一些装饰品而捕杀动物。与此略有不同的是旅游者为了留个纪念而追杀动物。狮子、老虎之类的大型动物在世界一些地方已被杀光。但有时人捕杀动物是由于害怕动物,认识这一点非常重要,大型的猫科动物就是这样被捕杀的。有时为了帮助动物生存要捕杀一些以减少其数量。据说加拿大杀海豹就是出于这个目的,而用海豹皮制革只是附带的。

许多人关心动物及野生动物的保护。不管动物濒危的原因是什么,保护方法其一就是把它们迁移到动物园和公园,在那儿喂养它们。完全有可能等它们繁殖出足够数量的后代以后,将来有一天放它们回归自然,其条件是它们还存活而且猎人不再捕杀。另一种方法是在动物生存的自然环境里创建野生动物保护区,由管理人员负责照料它们。然而保护区面积很大,管理人员少,但猎人捕杀动物的决心却很大。1980年初,在东部非洲,管理员与猎人发生过冲突。猎人持有现代化武器,有数人死亡。

在自然环境或接近自然环境里观赏野生动物是很有趣的,旅游业也可以给国家增加收入。动物仍然是资源,但它们是另一种形式的资源。

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