Bowhead whales, however, they're a bit more free-form in their songs.

然而，弓头鲸唱歌时更自由一些。

Some tortoises live for nearly 200 years. Bowhead whales can live even a decade or two longer.

有些海龟活了将近200年。弓头鲸甚至可以比海龟多活一二十年。

Bowhead whales feed on plankton, while ringed seals eat fish and other animals in which mercury has had the chance to accumulate.

因为露脊鲸以浮游生物为食，而环斑海豹则吃鱼和其它可能积聚汞的动物。

But the songs of bowhead whales are freer, she said.

但弓头鲸的歌声更自由，她说。

And ocean dwelling animals like bowhead whales and narwhals aren't immune to these changes either.

弓头鲸和独角鲸等海洋动物也不能幸免于这些变化。

Scientists think only male bowhead whales sing and that they are singing to find a mate.

科学家们认为只有雄性弓头鲸会唱歌，而且它们唱歌是为了寻找配偶。

Notable exceptions are the nearly song-like choruses of bowhead whales in summer and the complex, haunting utterances of the humpback whales.

有些值得一提的例外是：巨口鲸在夏天发出的声音几乎是歌曲一样的和声，而座头鲸发出的则是复杂的过耳难忘的声音。

Nelson Nungasat is captain of a whale hunting team. They rely on stable, thick ice to harpoon the 25 bowhead whales they're allowed to take each year for food.

Nelson Nungasat 是捕鲸队的队长。他们依靠稳定、厚实的冰来用鱼叉捕杀他们每年获准捕食的 25 头弓头鲸。