Why isn't the world covered in poop? - Eleanor Slade and Paul Manning

翻译人员: Carol Wang 校对人员: Yanyan Hong

[一只屎壳郎走进酒吧，问道： “这坨屎有主吗 (stool :屎/凳子)？”]

Somewhere near you, an animal is defecating.

在距你不远的某处， 某个动物正在排便。

In fact, each day, the animal kingdom produces roughly enough dung

事实上，动物王国 每天都会产生大量粪便，

to match the volume of water pouring over the Victoria Falls.

粪便总量足以与维多利亚 大瀑布的水量媲美。

So why isn’t the planet covered in the stuff?

但地球为何没有遍地粪便呢？

You can thank the humble dung beetle for eating up the excess.

这要感谢平凡的蜣螂（屎壳郎）， 他们消耗掉了多余的粪便。

Capable of burying 250 times their body weight in a single night,

这些昆虫勇士每天晚上 可埋掉自重 250 倍的粪便，

these valiant insects make quick work of an endless stream of feces.

它们快速工作，处理无穷无尽的粪便。

Over 7,000 known species of dung beetle run clean-up duty across six continents

已知的蜣螂品种有七千多种， 它们在6个大陆上负责清理工作

—everywhere except Antarctica.

——遍布南极大陆外的每个地方。

A dung beetle’s first task is to locate dung.

蜣螂的第一项任务是找到粪便，

Some live on the anal regions of larger animals,

一些蜣螂生活在大型动物的肛门附近，

ready to leap off when they defecate.

大型动物排便，它们就开始工作；

Others sniff out feces that animals leave behind.

其它蜣螂能闻到动物留下的粪便，

A pile of elephant dung can attract 4,000 beetles in 15 minutes.

一坨大象粪便 15 分钟内 就吸引 4000 多只蜣螂，

So once a beetle finds dung,

因此，一旦蜣螂发现粪便，

it must work quickly to secure some of the bounty for itself.

它必须快速劳作以占领工作地盘。

Most dung beetle species fall into one of three main groups:

多数蜣螂可分为三个主要组群：

rollers,

滚粪蜣螂、

tunnelers,

挖道蜣螂、

and dwellers.

和居粪蜣螂。

Dung rollers sculpt a ball of dung, and using their back legs,

蜣螂将粪便滚成球形，

用后腿快速滚动粪球，远离竞争者；

quickly roll it away from competitors.

Potential partners jump on the ball,

一些候选配偶则跳上粪球，

and once the ball-maker has selected their mate,

一旦滚粪球的蜣螂选定了配偶，

the pair dig their dung ball into the soil.

这对蜣螂就把粪球挖到土里。

Once it’s been buried, the female lays a single egg within the dung ball.

一旦粪球被掩埋，雌蜣螂 会在粪球中产下一个卵。

Tunnelers have a different approach.

挖道蜣螂的方式则不同，

Digging underneath a pat, some drag dung down into the soil

它们会在小块粪便下挖通道， 再把粪便拽进土里，

and pack it into clumps known as brood balls,

再将其聚拢成小堆，根据其形状 和大小分为育幼球、

dung balls,

粪球、

or dung “sausages,” depending on their shape and size.

或粪便“香肠”。

Male tunnelers sport a spectacular array of horns

雄性挖道蜣螂长着一列独特的角，

to fight each other for control of these tunnels,

用来对抗其他雄性 以获得这些通道的控制权，

which they then defend until the female’s laid her egg.

它们会守护这些通道， 直到雌蜣螂完成产卵。

Some male tunnelers avoid the fray by masquerading as hornless females

一些雄性挖道蜣螂会扮成 无角雌蜣螂，来避免争斗，

and sneaking into tunnels to mate while the guardians’ heads are turned.

并在守卫蜣螂不注意时， 悄悄溜进通道进行交配。

The third group of dung beetles, dwellers,

第三组是居粪蜣螂，

take the most straightforward approach,

它们采取了最直接的办法，

laying their eggs directly into a dung pat.

把卵直接产在粪便中。

This makes their offspring more vulnerable to predation

与挖道蜣螂和滚粪蜣螂相比，

这种方式使它们的后代 更容易遭到猎食。

than those of the tunnelers and rollers.

As the larvae feed, they riddle the dung pat with tunnels,

当幼虫进食时， 粪便会被钻出一些通道，

leaving remains that are quickly colonized by bacteria and fungi and weathered away.

快速寄生大量细菌和真菌， 最终使粪便分解。

Inside a tunnel, ball, or pat, once the larvae hatch,

在通道、粪球或粪块之内，

一旦幼虫孵化出来， 会以粪便为食，直至成蛹，

they consume the dung before metamorphosing into a pupa

and then an adult beetle.

之后发育成为成年蜣螂。

Besides clearing dung, the actions of these beetles

除了清理粪便，

蜣螂的活动对生态系统也非常重要。

have considerable ecological importance.

For one, they serve as secondary seed dispersers.

首先，它们实现了种子的二次传播。

Dung from monkeys,

猴子、野猪和其他动物的粪便中，

wild pigs,

and other animals is riddled with seeds from the fruits they eat.

包含大量

它们吃的水果的种子。

When beetles bury their dung balls,

当蜣螂填埋这些粪便时，

they inadvertently protect these seeds from predators

它们无意中保护这些种子 不会被其它动物们吃掉，

and increase the likelihood they’ll germinate.

增加了种子发芽的几率。

The advantage is so great that one South African plant

蜣螂带来了这种巨大好处，

非洲南部的一种植物甚至进化出 能产生形状气味类似粪便的种子，

has evolved to produce seeds that look and smell like dung

to trick beetles into burying them.

从而欺骗蜣螂填埋自己的种子。

Dung beetles also play important roles in agricultural systems.

在农业系统中，蜣螂也发挥重要作用。

Livestock, like cows and sheep, produce huge amounts of dung,

牛羊等牲畜会产生大量粪便，

which contains nutrients that can benefit plants.

其中包含有益植物的营养物质。

The beetles break up the dung and tunnel it deep into the soil,

蜣螂将粪便分解， 并挖地道深埋粪便，

bringing the nutrients into close contact with plant roots.

将营养物质带到植物根部。

Their services to farmers have been valued at $380 million a year in the US

在美国，它们每年对农民的贡献 价值可达到 3.8 亿美元；

and £367 million a year in the UK.

在英国，则可达到 3.67 亿英镑。

Dung beetles can even help us battle global warming

蜣螂甚至可以帮助我们 对抗全球变暖，

by reducing greenhouse gas emissions associated with farming.

它减少了农业相关的温室气体排放。

Microbes living in oxygen-poor livestock dung

一些微生物生活在 氧含量低的牲畜粪便中，

produce methane, a potent greenhouse gas.

它们产生甲烷，一种主要的温室气体。

But beetles oxygenate pats when they tunnel into them,

但蜣螂在粪便中挖道时， 则会带来氧气，

preventing the microbes from producing methane.

使这些微生物无法产生甲烷。

The dung beetle spreads seeds,

蜣螂能够传播种子，

helps farmers,

帮助农民，

and fights climate change

并对抗全球变暖 ——

—and accomplishes it all simply by doing its business.

它只是通过处理粪便， 就实现了这么多好处。

Maybe next time you come across some dung in the forest or a field,

也许下次你在森林 或田里见到它们时，

you’ll be tempted to take a closer look.

你会想好好地观察一下它们。

若你想了解更多关于 自然界铲屎官们的事，

强烈推荐 Douglas J Emlyn 的书：

《动物武器》。

内含更多关于蜣螂引人入胜的事实，

并深入探讨世界各地动物的生存策略。

请访问网站 ED.TED.COM/BOOKS，

阅读我们的完整建议和购书，

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