评论
打印
Eradicating a species might sound like something that's always bad.
要消灭一个物种听起来或许不是好事。
We put a lot of time and money into protecting life on Earth, not destroying it.
我们花了很多时间和金钱是要保护地球上的生命，而非摧毁它们。
But not all eradication plans target a species' entire population — just the parts that end up in places we don't want them to be.
但是并非所有物种消灭都是以整个种群为目标的—只是消灭某些地方的那一部分。
Invasive species can completely wreck an ecosystem, and we've tried all kinds of different ways to get rid of them over the years.
入侵物种可以完全破坏生态系统，多年来，我们尝试过了各种不同的方法消灭它们。
But some of those efforts … kind of backfired. Spectacularly.
但是其中一些努力...有些适得其反。
Take, for example, Australia's poster child for invasive species: the cane toad.
例如，澳大利亚入侵物种的典型代表：甘蔗蟾蜍。
Native to southern and central America, this toad is huge, averaging between 12 and 15 centimeters,
这种蟾蜍原产于南美洲和中美洲，平均身长在12到15 厘米之间，
and will eat almost anything, from carrion to insects to that bowl of cat food you left outside.
从腐肉到昆虫再到你留在门外的猫食，它什么都吃。
They'll also eat smaller frogs and toads, snakes, snails, and small mammals.
它们还吃自己小的青蛙和蟾蜍、蛇以及小型哺乳动物。
Basically, if it fits in the toad's mouth and it can catch it, it'll eat it.
从根本上来讲，只要是塞得进它嘴里的以及它能够抓到的东西，它都会吃掉。
Maybe the saddest part of the cane toad story is that they were introduced to Australia on purpose.
或许关于甘蔗蟾蜍最讨厌的部分是，它们是被有意引入澳大利亚的。
Farmers brought them in the 1930s to control the beetles eating their sugarcane crops.
20世纪30年代，农民们将它们引入用于控制那些吃他们甘蔗农作物的甲虫。
Unfortunately, the toads didn't stay in the sugarcane fields and started spreading across the continent.
不幸的是，蟾蜍并没有呆在甘蔗地里，还开始在这片大陆上肆意。
In their native environment, the toads are eaten by local fish, reptiles, birds, and bugs,
在它们的原产环境中，蟾蜍会被当地的鱼类、爬行动物、鸟类和昆虫吃掉，
but in Australia there are few predators that can eat them safely.
但是在澳大利亚，没几个能安全吃掉它们的捕食者。
Cane toads are poisonous, and predators not adapted to their poison often die after eating them.
甘蔗蟾蜍是有毒的，无法适应它们毒素的捕食者们经常在吃掉它们后死亡。
The toads can also spray poison from glands on their shoulders, which can cause intense pain and temporary blindness in humans,
蟾蜍还会从它们肩部腺体中喷射毒素，可以导致剧烈疼痛以及暂时失明，
making it both difficult and unpleasant to catch them. And when it comes to breeding, they're like warty, hopping tribbles.
因此抓住它们难且痛苦。说到繁殖，它们就像跳跃的多毛生物一样。
Females lay clutches of up to 35,000 eggs at a time, and can lay two clutches a year.
雌性蟾蜍一次产下多大35,000颗卵，一年可孵出两窝卵。
Even though less than 1% of the eggs make it to maturity, that's still a huge number of baby toads to deal with.
虽然能够发育成熟的卵子不足1%，但孵化出来的小蟾蜍数量非常之多。
Add all of this together, and it's not hard to see why estimates put the number of cane toads in Australia in the hundreds of millions.
所有这些加在一起，不难看出为什么澳大利亚要消除的甘蔗蟾蜍数量有亿万之多。
And, despite efforts to control them, they're spreading, moving into 40-60 kilometers' worth of new territory every year.
虽然在努力控制它们，但是它们每年都会向40-60公里的新土地扩散。
But there may be some hope for killing off the toads in one of Australia's native species: meat ants.
但澳大利亚的一种本地物种让消灭蟾蜍有了一些希望：食肉蚂蚁。
These little guys can kill and eat toads without being affected by their poison,
这些小家伙可以杀死并吃掉蟾蜍，还不受毒素影响，
and since the toads aren't native to Australia, they don't know to watch out for the ants.
由于蟾蜍并非原产澳大利亚，所以它们不知道如何戒备这些蚂蚁。
If scientists can encourage meat ants to colonize places where the toads like to hang out,
如果科学家可以鼓励食肉蚂蚁在蟾蜍喜欢出没的地方拓殖，
it's possible they could make an impact on the toad population.
或许它们可以影响蟾蜍数量。
Some people have also considered bringing in some of the toad's natural predators,
一些人也考虑引入一些蟾蜍的天敌，
but that's a risky proposition considering that importing non-native predators is what got Australia into this mess in the first place.
但是这也是有风险的，起初正是由于引入了非本土捕食者才让澳大利亚陷入这种混乱的。
The same control problems have happened with other invasive species, too.
其他几个入侵物种也面临同样的控制问题。
During the age of colonization, ships carrying explorers often brought along stowaways like mice and rats.
在殖民时代，探索者们搭乘的船只上经常有些偷渡者，比如老鼠和大鼠。
So, to control them, sailors often introduced foreign predators to take care of the pests.
所以，要控制住它们，水手们经常引入一些外来捕食者处理这些害虫。
You know the phrase "two wrongs don't make a right?" That's super applicable here.
大家都听过“以牙还牙是不可取的”吧。这句话在这里超级适用。
One popular import was the small Indian mongoose, a voracious predator that was introduced throughout the Pacific islands,
另一个受欢迎的引入物种是印度小猫鼬，它们是贪婪的捕食者，被引入太平洋小岛、
the Caribbean, Japan, and the Mediterranean to control invasive rodent and native snake populations.
加勒比海地区、日本以及地中海以控制入侵的啮齿动物和本土蛇。
The mongoose was a favorite because it will eat practically anything it can catch,
这种猫鼬深受大家喜爱，因为它们几乎会吃掉抓到了一切食物，
and anyone familiar with Rikki-Tikki-Tavi knows a mongoose can catch just about anything. That ability was a problem, though.
任何看过《瑞奇-提奇-嗒喂》的人都知道猫鼬可以抓到任何东西。虽然这种能力也是一个问题。
Because besides invasive rodents, they'll also eat plants, fruit, and eggs, making them a nightmare for native wildlife.
因为除了侵入的啮齿动物外，它们还吃植物、水果以及卵，是当地野生动植物的噩梦。
The mongoose is credited with the extinction of nearly a dozen species across the globe,
猫鼬被认为消灭了全球近十几种物种，
which was really not what the explorers who introduced them had in mind.
这真是那些将它们引入的探索者没想到的。
And they carry rabies, in case you needed another reason to wonder why we ever thought introducing them everywhere was a good idea.
并且它们还携带狂犬病，因此你有了想知道为什么引进它们会是个不错的主意的另一个理由。
Obviously, it's best to just avoid introducing foreign species in the first place,
显然，最好是从一开始就避免引入这些外来物种，
but it is possible to eradicate them if you're really dedicated.
但是如果你真的想，消灭它们也是可能的。
What happened on Macquarie Island, halfway between Australia and Antarctica,
澳大利亚和南极洲之间的麦夸里岛上发生的事情
gives you some idea of just how difficult eradication can be — but maybe also some hope.
能够告诉你要消灭侵入物种可以有多难—但是或许还是有希望的。
When the island was discovered by an Australian explorer in 1810, it became a hub for seal and penguin hunting.
1810年，一名澳大利亚探险家发现了这座岛，它成为了捕猎海豹和企鹅的中心。
Ships full of hunters brought along mice and rats, which threatened their food stores, so sailors brought in cats to control the rodents.
狩猎者的船只上有老鼠，威胁到了他们的食物存储，所以水手们带来了猫控制这些啮齿动物。
Fast forward 60 years, when another foreign species was introduced: the rabbit.
快进60年，当时另一个外来物种被引入：兔子。
It was an old tradition, meant to provide sailors with food in case a shipwreck stranded them on a deserted island.
这是一个老传统，本意是作为水手的食物，以防遇上海难将他们搁浅到荒岛。
Of course, rabbits multiply incredibly fast. And with lots of tasty rabbits around, the cats multiplied, too.
当然，兔子繁殖速度惊人。有了大量美味的兔子，猫的数量也增长了。
By 1970, there were more than 100,000 rabbits decimating Macquarie Island's plant life, and the cats had hunted two species of birds to extinction.
到1970年，超过10万只兔子肆意破坏麦夸里岛上的植物，那些猫将两种鸟类捕食到灭绝。
Conservationists were so concerned about the rabbit problem that they introduced yet another foreigner to the party:
自然资源保护者非常关心兔子问题，所以他们引入了另一种外来物：
a rabbit disease called myxomatosis.
多发粘液瘤病。
It was fairly successful, reducing the rabbit population to less than 20,000 within a decade.
这一方法相当成功，兔子数量在十年内减少到了不足2万只。
But with fewer rabbits to hunt, the cats became even more dangerous to Macquarie's native bird population.
但是由于能捕食的兔子数量变少，对麦夸里岛上的本土鸟类而言，猫变得更加危险。
By 1985, they'd done enough damage that conservationists began a campaign to shoot and kill all the cats.
到1985年，它们造成了足量的破坏，自然资源保护者开始了一场射杀所有猫的运动。
You can probably guess where this is going.
你或许可以猜到这件事情的结果。
In 2000, the last cat on Macquarie was shot, and in less than a decade the rabbit population was so out of control they'd stripped nearly half the island bare.
2000年，麦夸里岛上的最后一只猫被射杀，在不到十年的时间里，兔子数量失控，它们将岛上近一半的土地啃成了荒地。
To prevent even more damage, the Tasmanian government approved a 17 million dollar program to hunt down and kill every rabbit, mouse, and rat on the island.
为了防止更多破坏，塔斯马尼亚政府批准了一项1700万美元的计划要消灭岛上所有兔子、老鼠和大鼠。
The first wave of the project kicked off in 2011, spreading poisoned rodent bait over the landscape.
项目第一波在2011年开始，岛上铺满了有毒的灭鼠药。
That killed off the rats, mice, and many of the rabbits. Then, to kill off the remaining rabbits, they brought in the dogs.
老鼠、大鼠和很多兔子因而死亡。然后为了消灭剩下的兔子，他们引入了狗。
Before you facepalm too hard, the dogs were specially trained rabbit hunters that left the island with their trainers.
在你捂脸之前，狗狗都是接受过特殊训练的兔子捕手，它们和训练师被留在了岛上。
In April of 2014, after two centuries of damage, the eradication was complete.
2104年4月，遭受破坏两个世纪后，消灭工作完成。
So there might be hope for controlling some of the other invasive species causing problems all over the world.
所以控制全球范围内其他导致问题的入侵物种还是有希望的。
But what's happened in cases like these has taught us a lot about just how difficult,
但是这些例子中发生的事情告诉了我们所有的这些努力会有多么困难、
time-consuming, and expensive those efforts can be and how badly they can backfire.
耗时以及昂贵并且最后的结果会有多么适得其反。
So, next time you hear a story about unwanted pets being dumped into sewers, think less mutant ninjas and more ecological nightmare.
所以你下次听到关于有害宠物被丢弃在水沟的故事时，少想变异忍者，多想想生态噩梦。
Thanks for watching this episode of SciShow. If you're interested in learning more about how invasive species take over,
感谢收看本期《科学秀》。如果大家想了解更多关于入侵物种的知识，
you can watch Hank tell the story of bunny and Planet Wonderful.
可以观看Hank讲述的兔子和奇妙星球的故事。
