鼠兔消失背后的推手——气候变化

鼠兔是一种耳朵短而圆、没有尾巴的动物。据说鼠兔是因为外形酷似仓鼠而得名。鼠兔没有犬齿，门齿可不断生长。 前肢五指，后肢四趾。爪子细而弯，适合掘土。毛色因种而异，由灰色、灰褐色至锈褐色，夏毛要比冬毛淡。

Pikas, a hampster-size rabbit relative, have disappeared from a 64-square-mile plot in the northern Sierra Nevada—and climate change is a likely culprit[1].

[1]culprit

someone who has done something wrong 过失者；责任人 

Police hope the public will help them to find the culprits. 

警方希望公众能协助他们抓到罪犯。  

a fact or situation that is the reason for something bad happening 问题的起因；罪魁祸首 

Children in this country are getting much too fat, and sugar and sweets are the main culprits. 

该国儿童过于肥胖，糖和甜食是罪魁祸首。

Rabbit Relatives Reel from[2] Climate Change

[2]reel from: 遭受；灾难后蹒跚而行；受…的不好影响(必应词典网络释义)

The industry continued to reel from aftershocks of a disastrous year. 

工业在遭受灾年重创后依然摇摆不前。

正文：Up in California's High Sierra, above the dense pine forests, rocky habitats reign. And if you look carefully among the boulders（大圆石）, you might see a pika—a rabbit relative the size of a hamster（仓鼠）, with round ears and big eyes.

"Hikers oftentimes see them with little bouquets of wildflowers sticking out of their mouths." Joseph Stewart, a conservation biologist at the University of California Santa Cruz. "Maybe I'm a little biased, other people tell me they're very cute. I find them majestic. I feel like they're the lords of the mountain."

Stewart is also a skilled spotter of pikas. "You could say I've got a little bit of experience with that." Which makes it all the more strange that in five years of surveys—of 64 square miles of high mountain rocky habitats near Lake Tahoe—he found no pikas at all. In an area littered with decades-old pika droppings(小动物或鸟类的粪便).

It's relatively pristine[3] habitat, in the center, rather than the edge, of historic pika territory. So Stewart suspects the most likely culprit for this local extinction is rising temperatures, due to climate change. And the mercury's heading higher. "By 2050 we expect there's going to be a 97 percent decline in the area of climatically suitable habitat in the greater Tahoe area." The study is in the journal PLOS ONE. [Joseph A. E. Stewart,Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA]

[3]pristine: new or almost new, and in very good condition 崭新的；状态良好的 

pristine new offices 崭新的办公室 

Washing machine for sale - only two months old and in pristine condition. 出售洗衣机——只用过两个月，完好如新。

Pikas can still be seen elsewhere in Tahoe, and in other parts of the Sierras. Especially further south, where loftier summits allow pikas to roam higher to escape rising temperatures. But Stewart still worries about their eventual fate.

"We're depriving future generations of the ability to see this critter(生物). And pikas have been around longer than humans have been around. What right do we have to cause pikas and all the other species that are vulnerable to climate change to go extinct?"

—Christopher Intagliata

延展阅读

        2015年，3月11日，美国《国家地理》杂志报道：时隔22年再次发现伊犁鼠兔，这绝对是历时最长的捉迷藏游戏。

　　如果不是李维东碰巧赢了这场捉迷藏的游戏，伊犁鼠兔也许还不会大规模走进人们视野，隐藏在其背后的幕后推手——气候变暖，也许还不足以引起人们的警觉。

　　这一次，人们终于直观感受到气候变暖给生态圈带来的影响。伊犁鼠兔不得不为了找寻更低的温度艰难地向上攀爬。如果气温继续快速变暖，它们终究会失去家园。

　　更值得警醒的是，气候变暖对生态圈的影响不仅局限于高寒物种，它给陆地、海洋里的一些生物都带来了毁灭性打击。联合国政府间气候变化专门委员会(IPCC)第五次评估报告指出，在本世纪内，在中等至高排放情景下，气候变化的程度和速率可造成陆地和淡水生态系统(包括湿地)的构成、结构和功能面临发生突然和不可逆转的区域尺度变化风险。

　　报告认为，由于气候变化、毁林和生态系统退化，在21世纪，很多地区树木死亡和相关的森林枯死情况都会增加，很多森林动物都将处于由于栖息地减少而灭亡的危险境地。

　　海洋生物也不能幸免，气候变暖造成的海洋物种空间变化将造成高纬度地区发生物种入侵，热带和半封闭海域会出现较高的本地物种灭绝率。最低含氧区和缺氧的“死亡地带”逐步扩张，将进一步缩小鱼类栖息地。

　　尽管，自上世纪80年代以来，我国开始了对濒危物种抢救性保护工作，通过加强野外巡护、栖息地恢复、救助伤病个体、实施放归自然等一系列措施，促进濒危动物种群的扩大。但由于气候变暖是个缓慢的、长远的、不确定性较大的变化过程，在保护、研究濒危物种的过程中，这一因素容易被人忽略，相关基础科研工作薄弱，也很难提出有效的解决方法。

　　因此，动物保护工作者应当加紧气候变暖对物种影响的基础研究工作。同时，在气候变暖与物种进行栖息地拉锯战的过程中，公众应该做到不与濒危动物争领地。人类栖息地扩大、旅游业不断发展，这些同时存在的驱动因子可以对物种和生态系统造成交互、复杂和放大的影响。如媒体报道的那样，在美国5372米的高山上，研究人员看到融化的积雪、向上迁移的野生动物，以及当地居民紧随其后、不断扩大的种植区，而人类的这一行为可能加速迁徙动物的消失速度。（更多内容见http://t.cn/RNEVNno）