科学家们日前警告称，地球生物“第六次大灭绝”的速度比人们担心的还要快。
The sixth mass extinction of life on Earth is unfolding more quickly than feared, scientists have warned.
对动物灭绝趋势的首项全面分析显示，超过30%的脊椎动物（鱼类、鸟类、两栖动物、爬行动物和哺乳动物）的种类和数量都在减少。
More than 30% 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.
专家们在大约十年前就担心新一轮全球性物种灭绝即将到来。
Around a decade ago, experts feared that a new planetary wipeout of species was looming.
现在多数专家都一致认为新一轮物种灭绝已经开始，但新研究表明，物种灭绝的速度已经加快。
Today, most agree that it is underway, but the new study suggests that it is already ratcheting up a gear.
研究人员发现，在1900年至2015年间，他们所观测的177种哺乳动物已经失去了至少1/3的原始栖息地。生物多样性的减少最近加速了。
The 177 mammal species that were monitored have lost at least a third of their original habitat between 1900 and 2015, researchers found. The loss of biodiversity has recently accelerated.
该研究显示，包括猎豹、狮子和长颈鹿在内的数种哺乳动物在一二十年前还相对安全，而现在已经处于濒危状态。
Several species of mammals that were relatively safe one or two decades ago are now endangered, including cheetahs, lions and giraffes, the study showed.