評(píng)論
打印
Science and technology
科學(xué)技術(shù)
Invasive species
入侵物種
Boom and bust
繁衍與湮滅
Invasive Argentine ants may be less persistent than once feared
入侵性阿根廷螞蟻可能沒有想象的那么可怕
Ready for take-off
隨時(shí)準(zhǔn)備離開
DESPITE their name, Argentine ants are a well-travelled lot.
如果不顧它們的惡名，阿根廷螞蟻可以說是很好的旅行家。
Human commerce has allowed them to hitch rides from their homeland to every continent on the planet, with the exception of Antarctica.
人類的商業(yè)活動(dòng)將它們帶到了世界各大洲，南極洲除外。
And when they arrive, they often thrive.
并且當(dāng)它們到達(dá)時(shí)，它們就會(huì)繁衍。
At least 15 countries now host colonies, which frequently prosper at the expense of native species.
目前，至少15個(gè)國(guó)家受到外來物種的入侵，這種入侵是以犧牲本土物種為代價(jià)的。
This flexibility, combined with an aggressive temperament, makes them one of the world's best-known and most-hated invasive species.
這種侵略性及適應(yīng)性使得它們成為世界上最著名同時(shí)也是最令人深惡痛絕的入侵物種。
Yet, as any general knows, establishing a beachhead is not the same thing as conducting a successful, long-term occupation.
但是，眾所周知，建立一個(gè)灘頭陣地不同于成功地進(jìn)行一次長(zhǎng)期占領(lǐng)。
Argentine-ant colonies sometimes collapse suddenly, and with no obvious explanation.
阿根廷螞蟻的入侵有時(shí)突然毫無緣由地停止。
In a paper just published in Biology Letters, a group of researchers at Victoria University of Wellington, in New Zealand,
在最近發(fā)表在《生物書簡(jiǎn)》上的一篇文章中，新西蘭惠靈頓維多利亞大學(xué)的一組研究人員，
led by Meghan Cooling and Phil Lester,
由梅根?庫(kù)靈和菲爾?萊斯特領(lǐng)導(dǎo)，
describe their attempts to study such disappearances systematically.
描述了他們對(duì)這種系統(tǒng)性消失的研究。
The researchers examined 150 sites across the country where Argentine-ant nests had been recorded.
研究者們考察了全國(guó)范圍內(nèi)150個(gè)已經(jīng)被記錄下來的阿根廷螞蟻據(jù)點(diǎn)。
At 40% of them they found that the ants had vanished.
他們發(fā)現(xiàn)其中的40%已經(jīng)消失，
At many of the other sites, ant numbers were much reduced,
而在其他的據(jù)點(diǎn)，螞蟻數(shù)量減少，
with areas that once sported dozens of nests over hundreds of hectares reduced to just one or two colonies covering much smaller tracts of land.
原來幾百公頃的面積上有幾十個(gè)蟻巢，而現(xiàn)在一片小面積土地上只有一兩個(gè)聚居群。
And with the invaders gone, native ants seemed to be re-establishing themselves,
隨著侵略者離開，本土螞蟻似乎在重建自己的種群，
suggesting that the Argentine ants' impact on biodiversity had been transient, rather than permanent.
這表明阿根廷螞蟻對(duì)生物多樣性的影響只是暫時(shí)的。
A statistical analysis of the data yielded an estimate for the likely survival time of a typical colony of between 12.9 and 15.3 years,
數(shù)據(jù)統(tǒng)計(jì)分析估測(cè)了一個(gè)典型的聚居群可能的生存時(shí)間。
and suggested that warm and dry conditions were more favourable for survival than cold, wet ones.
該分析也表明，比起寒冷潮濕的條件，溫暖干燥的環(huán)境更有利于生存。
Exactly what caused the collapses is still not clear, although the researchers suspect that unfamiliar diseases may have played a role.
盡管研究者們懷疑不熟悉的疾病可能起到了一定作用，但導(dǎo)致阿根廷螞蟻消失的確切原因尚不清楚。
Unity is not strength
團(tuán)結(jié)不是力量
It is a plausible theory.
這種理論可信。
Because they grew from a small number of founder colonies,
因?yàn)樗鼈兪菑暮苄〉娜后w發(fā)展起來的，or possibly even a single one,
New Zealand's Argentine ants are genetically similar to one another.
新西蘭的阿根廷螞蟻之間的基因非常相似。
That may be one reason for their success: ant researchers hypothesise that, being so closely related,
這也許是它們成功的原因之一：螞蟻研究者假定，
the individual insects are unable to distinguish their nest mates from members of other colonies,
關(guān)系緊密的個(gè)體昆蟲不能夠把同巢穴的同伴同其它聚居區(qū)的成員區(qū)分開來，
which causes ants from different nests to co-operate as if they were kin,
這導(dǎo)致來自不同巢穴的螞蟻就像親戚一樣相互合作。
and has led students of the field to speak not of hundreds of individual infestations, but of a single, country-spanning super-colony.
這使得這一領(lǐng)域的學(xué)者不再談及成百的個(gè)體侵?jǐn)_，而是談及單一的、跨越全國(guó)的超級(jí)群體。
But a shallow gene pool can be a weakness, too.
但是，一個(gè)淺薄的基因庫(kù)也可能是一個(gè)弱點(diǎn)。
If one nest proves susceptible to some environmental factor,
如果一個(gè)巢穴容易受到某些環(huán)境因素的影響,
be it disease, predation, or even a cold snap or wet spell,
不管是疾病、掠食，亦或是寒流、潮濕期,
then it is likely that all the other colonies will share that vulnerability.
那么極可能其他的聚居群也有著同樣的弱點(diǎn)。
Now that they have documented the extent of the collapse the next step,
庫(kù)靈表示，他們現(xiàn)在已經(jīng)記載了蟻群消失的范圍，
says Ms Cooling, is to test the hypothesis of genetic vulnerability and try to work out precisely what causes the sudden reversals of formicine fortune she has seen.
下一步是驗(yàn)證基因脆弱性這一假設(shè)，并努力找出導(dǎo)致蟻群突然轉(zhuǎn)變的確切原因。
And it is not just ecologists who will be waiting for the results.
而等待這一結(jié)果的不止是生態(tài)學(xué)家。
New Zealand's government had reckoned it might have to spend NZ$68m a year keeping the newcomers under control.
新西蘭政府估計(jì)，每年可能會(huì)花掉NZ$68m用于控制新物種的入侵。
If Mother Nature can do the job instead, then it would represent a tidy saving for the country's exchequer.
如果自然母親能夠完成這項(xiàng)工作，那將會(huì)為國(guó)庫(kù)省下一大筆資金。
