经济学人下载:优生学 保护野生动物要坚守立"场"

The Americas
美洲

Protecting Wild Lives: Stand your ground beef
保护野生动物：坚守立“场”

Cows that are good at self-defense are also good for jaguars.
能自卫的牛也能抵御美洲豹。

Ranchers in Colombia's Meta department can be vengeful folk.
哥伦比亚梅塔省的农场主们有时候是群记仇的家伙。

From time to time jaguars emerge from a clump of forest, streak across the savannah and attack one of a panic-stricken herd of cows.
美洲豹时常从丛林深处冲出来，飞快地穿过大草原去袭击一群惊慌失措的牛。

When that happens, ranchers hunt the offender down and shoot it.
当这种情况发生的时候,农场主们会追捕这些入侵者并射杀它们。

That practice is endangering the cats' survival.
但是这种行为却使得美洲豹的生存受到威胁。

Panthera, a charity that manages “corridors” for jaguars that stretch from Argentina to Mexico, guesses that just 5,000 of the cats are left in los llanos, Colombia's scorching savannah.
潘瑟拉是一个专管美洲豹从阿根廷到墨西哥这个“廊道”的慈善机构，据他们猜测，大概仅有5000只美洲豹还存留在哥伦布亚灼热的大草原上。

It has come up with a less violent way of protecting both the jaguars and the cattle.
他们提出了一个不那么暴力的方法来同时保护美洲豹和牛群。

The idea is to teach cattle self-defense, or rather to breed the instinct into them.
这个点子就是教会牛去自卫，要不就给它们培养这样的本能。

The cows that graze in los llanos are mostly Zebu, which are popular with ranchers for their fast growth, large size and white hides.
在拉美大草原上放牧的大多数都是瘤牛，它们由于成长快、体型大、毛皮白，很受牧场主欢迎。

But they have an unfortunate habit of fleeing in all directions when danger approaches.
但是它们有一个坏习惯：当危险来临时，这些瘤牛会四散而逃。

Panthera's idea is to replace panicky Zebu with cattle that stand their ground, or to interbreed the two.
潘瑟拉的想法是把容易受惊的瘤牛换成坚守阵地的品种，或者把二者杂交。

Esteban Payán, who directs Panthera's operations in northern South America, chose San Martineros, a little-known subspecies of Criollo cattle descended from Spanish fighting bulls.
埃斯特班·巴杨管理潘瑟拉在南美洲北部的运营，他选择了圣马尔蒂内若斯牛，它是克里奥罗牛的一支鲜为人知的亚种，而克里奥罗牛是西班牙斗牛的后代。

Few jaguars dare to challenge a massed group of 500kg (1,100-pound) San Martineros, their horns levelled.
少有美洲豹敢于招惹一大群五百公斤（约一千一百磅）、双角水平的圣马尔蒂内若斯牛。

Docile with humans, they are fierce defenders of territory and their young.
它们驯服于人，却会凶狠地保卫自己的领地及幼犊。

Mr Payán recounts that San Martineros chased away a puma before it could eat a capybara it had killed in their paddock.
巴杨讲述道，有一次，圣马尔蒂内若斯牛撵跑了一只美洲狮，而它刚在围场里捕杀了一只水豚还没来得及吃。

Eugenics seems to work.
优生学似乎起作用了。

Since 2012 Mr Payán has been working with Eduardo Enciso, a rancher in Meta, who already had some San Martinero cattle.
自2012年巴杨便与爱德华多·恩西索一起共事，恩西索是梅塔的大牧场主，并且拥有几头圣马尔蒂内若斯牛。

Mr Enciso reports that both purebred San Martinero cows and the offspring of Zebus that have been inseminated by San Martinero bulls do indeed stick together when jaguars approach.
Enciso先生说道，当美洲虎向圣马丁内斯纯种牛以及瘤牛的后代（这种牛是圣马丁内斯纯种公牛受精而来的）靠近时，这两种动物会彼此紧靠。

Cattle that are just a quarter San Martinero may be just as brave, says Mr Payán.
巴杨说，哪怕仅有四分之一圣马尔蒂内若斯牛血统的杂交后代也能和纯种圣马尔蒂内若斯牛一样勇猛。

No jaguars have attacked cattle on Las Pampas, Mr Enciso's 4,000-hectare ranch, since the programme began, he says.
自从恩西索在他 4000公顷的牧场里开始实行这个项目，美洲豹不敢再袭击牛。

Zebu-only ranches in the area suffer a dozen attacks a year.
而同地区仅放牧瘤牛的牧场一年要遭受十几次美洲豹的袭击。

Panthera is trying to get other ranchers to adopt the technique, but just four have so far expressed interest.
潘瑟拉正试图让其他农场主采用这项技术，但迄今为止，仅有四位对此表示感兴趣。

Some contend that smaller San Martinero bulls cannot mount their Zebu cows, though Mr Enciso denies this.
一些人声称圣马尔蒂内若斯体型较小的公牛无法与母瘤牛交配，但是恩西索先生否认了这一点。

Certainly, there is nothing wrong with their libidos, he says.
它们绝对会产生性冲动，他说。

Perhaps more important, butchers think San Martineros are scrawny and dislike their reddish hue (hybrids can look like either variety or a mix of both).
或许更重要的是，屠夫认为圣马尔蒂内若斯牛骨瘦如柴，也不喜欢它们的发红的毛皮（杂种的外观可能继承双亲中的一方，也可能是二者的混合）。

Mr Enciso insists that San Martinero meat is more delicious than that of purebred Zebu.
恩西索坚称，圣马尔蒂内若斯牛的肉比纯种瘤牛的更美味。

If diners develop a taste for it, perhaps fewer jaguars will be shot.
如果食客开发了新的味蕾，被击杀的美洲豹的数量可能会减少。