科学家发现，鲸鱼可不是随意发出呼叫声的

As animals grow, the sounds they make change. But some sounds continue to change, even after an animal matures. That’s true for humans, and now it turns out to be true for North Atlantic right whales, too.

随着动物的成长，它们的声音也在发生着变化。有过，即使有些动物长大了，声音仍在继续发生变化。对于人类来说是这样的，对北大西洋鲸鱼来说也是如此。

A member of the baleen family of whales, the endangered North Atlantic right whales spend most of their time along the eastern coast of North America from Canada’s Bay of Fundy south to Florida.

濒临绝种的北大西洋鲸鱼，作为鲸族的一员，大部分时间都沿着北美东部海岸，从加拿大的芬迪湾南部到佛罗里达。

Syracuse University biologist Holly Root-Gutteridge analyzed recordings of whale calls to see if researchers could use those sounds to identify individual whales. In an audio program on a computer screen, a call has a particular shape.

锡拉丘兹大学生物学家Holly Root-Gutteridge分析了鲸鱼呼叫的录音，看研究人员是否可以使用这些声音来识别鲸鱼。在电脑屏幕上的音频节目中，这些呼叫声具有特定的形状。

"Staring at these calls all day, I started to notice they were changing. And then we looked a little bit harder at the data, and realized that they weren’t just changing from being a little tiny baby to being a fair sized adult…but that they kept changing over time."

“整天盯着这些音频，我开始注意到他们正在改变，然后我们看数据越来越困难，并意识到，他们不仅仅是从一个小婴儿变成成年鲸...... 而是，一直在不断变化。”

Root-Gutteridge and her colleagues rounded up seventeen years’ worth of whale recordings. In all, they gathered nearly a thousand calls from 49 individual whales between the ages of one month and 37 years.

Root-Gutteridge和她的同事收集了十七年的鲸鱼叫声记录。总的来说，他们手上有来自一个月至37岁之间的、49头鲸鱼的近千条声音。

Like many other animals, the calls of the infants were both shorter and less structured than those of the adults. Mature whales produced calls that were clearer, longer, and more structurally complex. But the researchers also found that the calls continued to develop long after the whales reached sexual and physical maturity.

像许多其他动物一样，婴儿的呼唤比成年人的声音更短且结构更少。成年鲸鱼产生的呼叫更清晰、更长、结构更复杂。但研究人员还发现，在鲸鱼达到性和身体成熟之后的很长一段时间内，这些呼声仍在继续发展。

"Instead of just changing from the age of 0 to 15 when they’re pretty much full-grown, they kept changing after the age of 15 and just kept going throughout their whole lives. Compared to say, a bird, where usually they get to their full-grown state and then they don’t change these calls."

“它们不仅从0岁到15岁时的快速生长期声音在改变着，15岁后也在不断变化，并持续一生。相比之下，鸟类完全成熟后的呼叫声往往不会再改变。”

The results were published in the journal Animal Behaviour. [Holly Root-Gutteridge, et al., A lifetime of changing calls: North Atlantic right whales,Eubalaena glacialis, refine call production as they age]

该研究结果发表在动物行为期刊上。[Holly Root-Gutteridge，et al。 终生改变呼叫：北大西洋鲸鱼，Eubalaena glacialis，随着年龄的增长改善呼叫]

"Well, it means that instead of having a completely instinctive reaction where they always make the same call in response to the same stimuli—a reflex, basically—that the whales are capable of changing what they’re calling and how they’re communicating. Which means that they may be thinking about what they call."

“好吧，这意味着，他们总是对相同的刺激做出相同的呼声——基本上是一种定势————鲸鱼能够改变他们所呼叫的内容，以及他们如何去沟通，并非天生本能的反应。这意味着他们在呼叫时是经过思考了的。“

In other words, understanding the calls of North Atlantic right whales might shed some light on the minds of North Atlantic right whales.In the meantime, scientists announced recently that they did not observe any newly born North Atlantic right whales this year—bad news for an already imperiled species. With luck, the work of biologists like Root-Gutteridge might offer insights that help us we try to help them survive.

换言之，理解北大西洋鲸鱼的呼唤，可能会对分析大西洋鲸鱼的头脑带来一些启发。同时，科学家们最近宣布，他们今年没发现有新出生的北大西洋鲸鱼——对这个已近濒危的物种来说真是一个坏消息。幸运的是，像Root-Gutteridge这样的生物学家的工作，可能会对我们挽救这个物种的生存有帮助。