野生動物第六次滅絕正在加速

The sixth mass extinction of life on Earth is unfolding more quickly than feared, scientists have warned.

科學家們警告稱，全球野生動物“第六次大滅絕”的速度比預期的還要快。

More than 30 percent of animals with a backbone - fish, birds, amphibians, reptiles and mammals - are declining in both range and population, according to the first comprehensive analysis of these trends.

對動物滅絕趨勢的首個全面分析結果顯示，超過30%的脊椎動物，例如魚類、鳥類、兩棲動物、爬行動物以及哺乳動物等，它們的種類和數量都在減少。

"This is the case of a biological annihilation occurring globally," said Stanford professor Rodolfo Dirzo, co-author of a study published last Monday in the peer-reviewed US journal, Proceedings of the National Academy of Sciences.

這一研究結果近日在同行評審期刊《美國國家科學院院刊》上發表，該報告的合著者斯坦福大學教授魯道夫?狄爾佐說：“這就是全球性生物大滅絕的現狀。”

Around a decade ago, experts feared that a new planetary wipeout of species was looming.

專家們在大約十年前就預料到新一階段的全球性生物大滅絕即將到來。

Today, most agree that it is underway - but the new study suggests that the die-out is already ratcheting up a gear.

現在多數專家都一致認爲生物滅絕已經開始，但是新的研究表明，生物滅絕已經加快了速度。

It provides much-needed data about the threat to wildlife, mapping the dwindling ranges and populations of 27,600 species. For 177 mammals, researchers combed through data covering the period 1900 to 2015.

研究中提供了威脅野生物種的重要數據，繪製出了27600種生物種類和數量下降的分佈圖。其中，研究人員專門針對177種哺乳動梳理出了1900年至2015年間的數據。

The mammal species that were monitored have lost at least a third of their original habitat, the researchers found.

研究人員發現，他們所觀測的這些哺乳動物已經失去了至少三分之一的原始棲息地。

Forty percent of them - including rhinos, orangutans, gorillas and many big cats - are surviving on 20 percent or less of the land they once roamed.

包括犀牛、猩猩、大猩猩以及大型貓科動物等在內的40%的哺乳動物，現在的活動區域僅爲它們原有棲息地的20%或者更小。

The loss of biodiversity has recently accelerated.

生物多樣性的減少最近也加速了。

"Several species of mammals that were relatively safe one or two decades ago are now endangered," including cheetahs, lions and giraffes, the study showed.

研究顯示，包括獵豹、獅子以及長頸鹿在內的數種哺乳動物“在一二十年前還相對安全，然而現在處於瀕危狀態。”

Globally, the mass die-off - deemed to be the sixth in the last half-billion years - is the worst since three-quarters of life on Earth, including the non-avian dinosaurs, were wiped out 66 million years ago by a giant meteor impact.

6600萬年前，由於一顆巨大隕石撞擊地球，包括非鳥翼類恐龍在內，地球上四分之三的生物都遭到滅絕。這次全球性生物滅絕被認爲是五億年以來第六次生物大滅絕，而且是自恐龍滅絕以來最嚴重的。

There is no mystery as to why: our own ever-expanding species - which has more than doubled in number since 1960 to 7.4 billion - is eating, crowding and polluting its planetary cohabitants out of existence.

引發生物大滅絕的原因顯而易見：人類不斷繁衍壯大，人口達到74億，相比1960年不止翻了一番。人們以動物爲食，並把動物們擠出家園，同時還污染環境，讓動物們無法生存。

By comparison, there are as few as 20,000 lions left in the wild, less than 7,000 cheetahs, 500 to 1,000 giant pandas and about 250 Sumatran rhinoceros.

相比之下，在野外生活的獅子只剩下20000只，獵豹只有不到7000只，大熊貓只剩下500到1000只，蘇門答臘犀牛也只有250頭左右。

The main drivers of wildlife decline are habitat loss, overconsumption, pollution, invasive species, disease, as well as poaching in the case of tigers, elephants, rhinos and other large animals prized for their body parts.

野生動物減少的主要原因有：失去棲息地、人類過度消耗、環境污染、物種入侵、感染疾病以及偷獵活動（因爲老虎、大象、犀牛以及其他大型動物的一些身體部位價值連城）。

Climate change is poised to become a major threat in the coming decades, with some animals - most famously polar bears - already in decline due to rising temperatures and changing weather patterns.

氣候變化在未來的幾十年將成爲生物滅絕的主要威脅因素。由於氣溫升高，天氣模式變化，一些動物——比如最著名的北極熊——已經減少。

"The massive loss of populations and species reflects our lack of empathy to all the wild species that have been our companions since our origins," said lead author Gerardo Ceballos of the National Autonomous University of Mexico.

“野生動物自古是人類的朋友，從數量和物種的大幅下降可以看出，我們缺少對這些動物的憐憫之情，”墨西哥國立自治大學的首席作者熱拉爾多?塞巴洛斯說。

Beyond any moral imperative, there are practical reasons to rue the eclipse of animals, whether megafauna or smaller and less "charismatic" creatures, the researchers said.

研究人員們說，無論是巨型動物、小型動物還是那些不太“有魅力”的動物，我們對它們的滅絕懊悔不僅僅是出於道德責任，還有更實際的原因。

The vanishing of a top-level carnivore or herbivore can have a cascading effect down the food chain, disrupting entire ecosystems.

頂級肉食動物和食草動物如果消失，那麼就會對下層的食物鏈產生級聯效應，進而摧毀整個生態系統。

Other species directly provide "services" to humans, such as honeybees that pollinate crops or birds that ensure pest control.

其他物種還直接“服務”於人類，比如蜜蜂給莊稼傳授花粉，小鳥吃害蟲。

Previous studies show that ecosystems under stress, while resilient, have a breaking point - rapid change can lead to collapse.

既有的研究表明，在壓力下的生態系統，即使有自我恢復能力，它也是有極限的。物種急劇的變化能讓生態系統徹底崩潰。