纪录片《冰冻星球》 第7期 世界的尽头（7）（在线收听）

These bison are even bigger than their southern cousins

这些野牛较其低纬同类体型更大

and the largest land animals in North America.

是北美洲最大的陆生动物

For generations, wolves and bison here

狼与野牛在此代代抗衡

have been shaped by their battles with each other,

于是得以进化

making each the most impressive of its kind.

成为同物种的佼佼者

The bison will not stay long among the trees.

野牛不会在林中栖息过久

They're not safe here.

这里并非安全地带

The wolves are closing in,

狼群逐渐靠近

but their chance of ambushing the bison in the woods has passed.

可惜在林中伏击野牛的机会业已丧失

Their prey are now in the open

猎物已进入空旷区域

and grouped together for safety.

结伴而行 以保安全

The wolves will need to work as a team

狼群若想一击成功

if they are to make a kill.

便需要协作作战

They circle the herd, trying to unsettle it

它们呈围攻之势 企图扰乱阵脚

and split it up.

进而各个击破

But the bison are armed and dangerous.

不过野牛角锋锐利 相当危险

They will be safe as long as they stick together.

如能互为犄角 便可保持不败

The wolves up their game, harrying the herd,

狼群让战斗升级 率先挑衅

a ploy to trigger a stampede

先对牛群进行骚扰

and split away one of the smaller ones.

从而孤立出一个孱弱者

The bison form a defensive circle around their young,

野牛们以幼崽为中心 组成防御性外围

horns pointing outwards.

它们的角朝外