听力文本

Snow geese. They winter along the Gulf of Mexico,
雪雁。它们在墨西哥湾越冬，
and in spring they fly the entire length of North America to reach the Arctic tundra.
等到春天便一路飞过北美洲，来到这里的北极苔原
Five million birds make this journey every year.
每年有五百万只雪雁都是这样迁徙。
Their marathon migration is almost 3,000 miles long and has taken them three months.
这场马拉松式的迁徙长达三千英里，耗时多达三个多月。
Exhausted and starving, they touch down inside the Arctic Circle,
虽然早己精疲力竭，饥肠辘辘，但它们终于返回了北极圈，
back at their traditional breeding grounds at last.
返回了它们阔别已久的繁殖地。

Snow geese pair for life.
雪雁一生只忠于一个配偶。
As soon as couples arrive, they must stake a claim to a nesting patch.
一对雪雁来了之后就必须取得自己的筑巢地。
Ideal sites are in short supply and quarrelsome neighbours are all around.
理想的地方寥寥无几，邻里纠纷时常发生。
Disputes can be vicious.
有时闹得杀气腾腾。

视频及简介

剧组将镜头对准惊恐的蒙古小羚羊，亲眼目睹它们的季节迁徙的人其实很少。同时你不会错过第一次出现在摄影机镜头里的长相怪异的藏狐。历时六个星期，剧组为了跟踪一个企图捕杀大象的狮群，用夜视镜近距离地拍下了当时混战的场面。