(单词翻译:单击)
听力文本
This is Scientific American — 60-Second Science. I'm Jason Goldman.
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.
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.
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.
"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."
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.
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.
"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."
The results were published in the journal Animal Behaviour.
"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."
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.
Thanks for listening for Scientific American — 60-Second Science. I'm Jason Goldman.
参考译文
这里是科学美国人——60秒科学。我是杰森·古德曼。
在成长阶段，动物的声音会发生变化。但是有些动物即使在成年之后声音还会继续变化。人类是如此，现在事实表明北大西洋露脊鲸也是如此。
作为须鲸家族的成员，濒临灭绝的北大西洋露脊鲸一生中大部分时间都在沿着北美大陆东部海岸活动，它们的活动范围北至加拿大的芬迪湾，南到美国佛罗里达半岛。
雪城大学的生物学家荷莉·鲁特·古特里奇分析了北大西洋露脊鲸的叫声录音，以便判断研究人员能否利用这些声音来辨别不同的鲸鱼。在电脑屏幕上一个音频程序里，鲸鱼的每一次叫声都会产生一条形状独特的线条。
“整天盯着这些声音线条，我开始注意到，它们一直在变化。然后我们把更多注意力放在数据变化上，才发现原来它们的声音不仅从鲸鱼宝宝到成年时期有变化，而且在成年后还在一直改变。”
鲁特·古特里奇和团队成员收集了北大西洋露脊鲸长达17年的录音。这里面有来自49头鲸鱼的1000多次叫声，这些鲸鱼的年龄从一个月到37岁不等。
与其他动物一样，幼鲸比成年鲸鱼的叫声更短促，结构更少。成年鲸鱼发出的声音更加清晰、绵长，结构上也更加复杂。但研究人员同时也发现，这些叫声在鲸鱼的性和生理成熟很久之后仍然在继续变化。
“它们声音变化的时段不仅是从0岁到大体成年的15岁之间，而是在15岁之后还会变化，这种变化贯穿它们的一生。而很多其他动物，比如一只鸟，通常在发育完全后声音就不会再改变。”
这项研究发表在《动物行为》期刊上。
“这意味着露脊鲸发声并不是一个完全出自本能的行为，比如面对某种特定的刺激会发出特定的叫声，而是鲸鱼拥有改变叫声和交流方式的能力。这意味着它们或许能够思考它们在叫什么。”
换句话说，了解北大西洋露脊鲸的叫声，或许有助于理解它们的想法。
另一方面，研究人员表示，今年他们还没有发现任何新出生的北大西洋露脊鲸，这对于这个本就濒危的物种来说是个坏消息。希望鲁特·古特里奇等生物学家的工作能为露脊鲸的保护提供更多启示。
谢谢大家收听科学美国人——60秒科学。我是杰森·古德曼。
译文为可可英语翻译，未经授权请勿转载！
重点讲解
重点讲解：
1. round up 使聚拢；使聚集；
I spent the morning trying to round up the documents I needed.
我用上午的时间尽力搜集所需要的文件。
2. in all 总共；合计；
Six hours were lost in all.
一共浪费了6个小时。
3. be capable of 有…能力的；能够…的；
Most living creatures are capable of adaptation when compelled to do so.
大多数生物都能在迫于压力的情况下适应新环境。
4. shed light on 使（某事）显得非常清楚；使人了解（某事）；
In order to shed light on the incident, the witness spelled out the whole event.
为了让大家明白此事件，目击者详细的解释了整件事的来龙去脉。
