bbc纪录片：【BBC地球脉动】两极之间 5

英语自学网

Some herds travel over 2,000 miles a year in search of fresh pastures. This is the longest overland migration made by any animal. They're constantly on the move. Newborn calves have to be up and running the day they are born. But the vast herds do not travel alone. Wolves. Packs of them, eight to ten strong, shadow the migration. And they are hungry. It's the newly born calves that they are after. Running directly at the herd is a ploy to generate panic. The herd breaks up and now it's easier to target an individual. In the chaos a calf is separated from its mother. The calf is young, but it can outrun the wolf if only it manages to keep its footing. At this stage the odds are even. Either the caribou will make a mistake or after a mile the wolf will give up.有一些驯鹿群每年迁徙3000多公里寻找鲜嫩的草场。这是动物界距离最长的陆地迁徙。它们一直不停地运动，新出生的小驯鹿出生的当天就必须站起来奔跑。但这些驯鹿并不是单独旅行。还有……狼。狼成群行动，8到10只一群，如影随形地跟着迁徙队伍。而且它们饥肠辘辘。它们的目标是那些刚出生的小驯鹿。直接冲向驯鹿群是它们的计谋之一，这样可以引起恐慌。驯鹿群四散逃跑，这样狼就更容易瞄准单个目标。混乱之中，一只小驯鹿和妈妈失散了。这只驯鹿虽然幼小，但如果脚步不打滑，它的速度可以超过狼。在这个赛场上，它们各有优势。如果小驯鹿不犯错误，追赶1000多米之后狼就会放弃。