The pack ice is returning and the arctic whales mustn't linger.
浮冰群就要重现，而北极的鲸类已不可逗留此地。
Bowheads, belugas and narwhals head for open water on the southern edge of the Arctic Ocean.
弓头鲸、白鲸以及角鲸纷纷向北冰洋南端的开阔水面游去。
A thirty thousand square kilometers of ocean turns to ice everyday.
每天有三万平方公里的海面冻结成冰。
As the days grow colder, millions of seabirds flee the coming darkness of the polar winter.
随着天气越来越冷，几百万只海鸟赶在黑暗的冬季来临前逃离北极。
In Hudson bay, the polar bears are still waiting for the pack ice to spread south.
在哈德逊湾，北极熊们仍在等待浮冰区向南扩散。
As November approaches, the usually solitary males not only tolerate each other's presence, they even begin to socialize.
接近十一月的时候，通常喜好独居的公熊们不仅变得相互容忍对方的存在，甚至开始相互交际。
With no food or females to compete over, these play fights are harmless, but the contests mean each bear can gage the strength of its opponents.
由于没有食物或配偶可争，这种游戏般的打斗毫无伤害，但这样的比赛却可以使每头公熊估量出对手的实力。
If they meet again during the mating season next spring, they must fight to win access to females.
假如它们来春的交配期再次相遇，它们就必须一战以赢得母熊的芳心。
As winter closes in, the sea ice spreads south to Hudson bay.
随着冬季的临近，海冰逐渐向南扩散到哈德逊湾。
For the polar bears, the return of the ice means respite from their hunger is finally insight.
对于北极熊来说，冰的回归意味着饥饿可以等到缓解。
They can at last head back to their hunting grounds in the frozen ocean.
它们终于可以重返这冰冻海面上自己的捕猎场了。
Like all the animals that live above and below the ice, the polar bears have adapted to survive in one of the most hostile habitats on earth - the Arctic Ocean.
与所有生活在冰层上下的动物一样，北极熊们已经适应，并且能够生存在地球上环境最恶劣的栖息地之一：北冰洋。