研究顯示 露脊鯨成年後也會變聲
As animals grow, the sounds they make change. But some sounds continue to change, even after an animal matures.
隨着動物的成長，它們的聲音也在發生着變化。有過，即使有些動物長大了，聲音仍在繼續發生變化。That's true for humans, and now it turns out to be true for North Atlantic right whales, too.
對於人類來說是這樣的，對北大西洋露脊鯨來說也是如此。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.
北大西洋露脊鯨是須鯨家族的成員，也是瀕臨滅絕的一種動物。它們大部分時間都在沿着北美大陸東部海岸活動，範圍是加拿大的芬迪灣到佛羅里達。
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.
錫拉丘茲大學生物學家霍利·羅特·特里奇分析了鯨魚呼叫的錄音，以便判斷研究人員是否可以使用這些聲音來識別鯨魚。在電腦屏幕上的一個音頻程序裏，鯨魚的每一次叫聲都會產生一條形狀獨特的線條。"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."
“整天盯着這些聲音線條，我開始注意到，它們一直在變化。然後我們把更多注意力放在數據變化上，才發現原來它們的聲音不僅從鯨魚寶寶到成年時期有變化，而且在成年後還在一直改變。”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.
羅特·特里奇和她的同事收集了這種鯨魚十七年的錄音。總的來說，他們手上有來自一個月至37歲之間的49頭鯨魚的近千條叫聲。
Like many other animals, mature whales produced calls that were clearer, longer, and more structurally complex.
與其他動物一樣，成年鯨魚發出的聲音比幼年時期的更加清晰、綿長，結構上也更加複雜。But the researchers also found that the calls continued to develop long after the whales reached sexual and physical maturity.
但研究人員同時也發現，這些叫聲在鯨魚的性和生理成熟之後很久仍然在繼續變化。"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."
“它們不僅從0歲到15歲時的快速生長期聲音在改變着，15歲後也在不斷變化，並持續一生。相比之下，鳥類在完全成熟後，其鳴叫聲往往不會再改變。”"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."
“這意味着，北大西洋露脊鯨發聲並不是一個完全出自本能的行爲，比如面對某種特定的刺激會發出特定的叫聲，而是鯨魚擁有改變叫聲和交流方式的能力。這意味着它們在發聲時或許是經過思考了的。”In other words, understanding the calls of North Atlantic right whales might shed some light on the minds of North Atlantic right whales.
換句話說，對北大西洋露脊鯨叫聲的理解，可能會對分析它們的頭腦帶來一些啓發。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.
另一方面，科學家們最近宣佈，他們今年還沒有發現新出生的北大西洋露脊鯨--這對於這個本就瀕危的物種來說是個壞消息。但願，像羅特·特里奇這樣的生物學家的工作，能對我們挽救這個物種的生存提供更多啓示。
