但由于夏季氣溫升高了約1.5℃,牧草地變得更茂盛,這使得雌性馴鹿到了秋天會變胖且能孕育更多小鹿.
However, warmer winters have brought with them greater rainfall which freezes when it settles on the snow, thereby locking out the reindeer from the life-sustaining food below.
然而,溫暖的冬天帶來了更多的降雨,雨水落在雪地里會結(jié)冰,阻止馴鹿獲得冰面下維持生命的食物.
As a result, female reindeer are becoming starved, causing them to abort their calves or giving birth to much lighter young.
結(jié)果,饑餓的雌性馴鹿就會流產(chǎn)或者誕下體重較輕的小鹿.
The average mass of an adult reindeer in 1994, when the survey began, was 55kg, but by 2010 it had dropped to 48kg.
1994年調(diào)查開始時,一頭成年馴鹿的平均體重為55公斤,但是到2010年,成年馴鹿的平均體重已經(jīng)下降到48公斤.
Professor Steve Albon, an ecologist at the James Hatton Institute in Aberdeen, said that, because the mammals have a relatively high surface-area-to-volume ratio, they are no particularly energy efficient.
史蒂夫•阿爾博教授是阿伯丁詹姆士赫頓研究院的生態(tài)學(xué)家.他表示,這種哺乳動物的表面積體積比相對較高,他們沒有特殊的節(jié)能功能.
Reindeer can often access the meagre food sources beneath the snow by clearing it away with their antlers, but they cannot break through the hard ice.
馴鹿通常用鹿角清除積雪,獲得下面寥寥無幾的食物,但他們無法弄破堅冰.
Without access to the food in winter, calves are being born far lighter than they should be.
雌性馴鹿冬天吃不到食物,生下來的小鹿就比應(yīng)有的體重輕得多.
Numbers of reindeer have also soared in the past 20 years, meaning that those which are born are facing greater competition for food.
馴鹿的數(shù)量在過去的20年里飆升,這意味著生下來的小鹿面臨著更加激烈的食物競爭.
"The implications are that there may well be more smaller reindeer in the Arctic in the coming decades, but possibly at risk of catastrophic die-offs because of increased ice on the ground," said Professor Albon.
阿爾博教授稱,"這背后的含義是,雖然未來幾十年里很可能出現(xiàn)更多瘦小的馴鹿,但地上的冰面越來越大,它們因此存在滅絕的風(fēng)險."
Despite the gloomy findings, reindeer appear to be suffering less from the impact of climate change than some other arctic species.
盡管這一研究發(fā)現(xiàn)很悲觀,但是馴鹿受氣候變化的影響似乎比其他北極生物要小.
Last week the scientists warned that a third of the world's polar bears could disappear in the next 40 years to melting Arctic sea ice.
科學(xué)家們上周警告稱,隨著北冰洋冰面的消融,全球三分之一的北極熊可能在未來40年內(nèi)消失.
