字神帝國英語天地

今日主題：Polar Bears Must Work Harder on Faster Sea Ice Treadmill  奔跑吧，北極熊！

洪欣老師推薦：托福聽力最好的課外教材：60-Second Science
康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://goo.gl/SW7sUJ

只有音檔怎夠，聽不懂地方，不用怕，康康幫你準備好中英文稿了：

中英文稿：
Polar bears live on floating rafts of sea ice, hunting for seals. But in the Arctic Ocean north of Alaska, the cold polar wind constantly blows that ice from east to west. Which means that the polar bears there are on a kind of treadmill.
北極熊，它們棲息在浮冰之上，靠獵食海豹維生。在阿拉斯加以北，北冰洋之上，冰冷而不絕的極地海風推動著浮冰自東往西行進。對於北極熊而言，這就像跑步機一樣。

"If the bears don't compensate that drift, they would all drift to Russia. So over the course of a year they need to walk back against that prevailing drift to remain in the Alaska territories." David Douglas, a biologist with the U.S. Geological Survey in Juneau, Alaska.
“如果北極熊不走動以抵消漂流帶來的位移，它們將隨浮冰漂到俄羅斯附近。因此全年之中，它們需要不停的移動，以抵消永不停息的浮冰漂移，確保自己始終在阿拉斯加區域內。”美國地質調查局亞拉斯加分部，朱諾地區的生物學家，大衛•達格拉斯如是道。

Recently, researchers realized that the ice drift in this part of the Arctic Ocean has accelerated from about three kilometers per day up to five. That's probably because climate change has made the sea ice thinner and easier for the winds to push. And that means the polar bear treadmill has sped up too.
最近，研究人員發現該地區的冰川漂移速度從原來的3km/h提升到了5km/h。那可能是因為氣候變化使浮冰變得更薄，更易受到海風的驅動。同時，這種加速令到北極熊的“跑步機”變得更快。

Douglas and his colleagues tracked Alaskan polar bears fitted with radio collars. They found that the animals are working harder than ever to compensate for the faster drift. And just like when we exercise, bears have to eat more food to make up for the extra calories they're burning—between one and four more seals per year, depending on whether the bears are single or raising cubs.
道格拉斯和他的同僚通過無線頸環追蹤著阿拉斯加地區的北極熊。他們發現，相比過去，這些熊需要更為努力地去抵消漂流作用。而正如我們做運動一樣，這些北極 熊需要更多的食物去補充更多的走動所帶來的體力消耗。它們需要比以往尋覓多一到四頓的海豹，這取決於它是孤身一熊還是在撫養幼崽。

"While that may not seem like a lot of seals or a big demand, it also comes at a time when the habitat that they have to hunt in is shrinking. So they have less area on which to hunt seals, at the same time needing to hunt more."
“或許那看起來並不是很多海豹，也不是很大的需求，但這個現象剛好與它們的覓食地正在萎縮的情況同時發生。因此這些北極熊狩獵的地區變小了，卻有了更多的食物需求。”

Douglas, after presenting the research December 15th at the fall meeting of the American Geophysical Union in San Francisco. [David Douglas et al, Increased Arctic Sea Ice Drift Alters Polar Bear Movements and Energetics]
這些對話錄製於12月15日，在三藩市舉行的美國地球物理學會秋季會議上。

He's particularly worried that the changes in sea ice may hurt young bears' chances of survival, especially in the southern Beaufort Sea, north of Prudhoe Bay. Researchers have studied these bears for more than 30 years, and have watched their numbers decline.
道格拉斯憂心於這種浮冰的變化會削減年幼的北極熊的生存率，尤其是在波弗特海以南、普拉德霍灣以北的地區的北極熊。研究人員對這些北極熊進行了長達三十年的研究，見證了它們數量的減少。

"We didn't see this coming three decades ago when we started tracking bears. We thought we were simply getting baseline data on a population, and never foresaw that the Arctic would undergo such dramatic change." That, like the sea ice, may be accelerating.
“在三十年前，當我們剛開始追蹤北極熊的時候，我們沒想到這樣的事情會發生。我們以為我們在簡單地收集種群數量的標準資料，而並沒有預見到北極圈會發生如此大的變化。”而這種變化，就像浮冰一樣，也在不停地加速。