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Thank you so much. I'm going to try to take you
譯者: Geoff Chen 審譯者: chufung dou
on a journey of the underwater acoustic world
非常感謝。我要帶大家進入一段
of whales and dolphins.
鯨魚和海豚的
Since we are such a visual species,
水下聲音世界
it's hard for us to really understand this,
由於我們多依賴視覺,
so I'll use a mixture of figures and sounds
所以,要真正理解這些有點難度
and hope this can communicate it.
因此我會結合圖表與聲音 來說明
But let's also think, as a visual species,
希望這樣能把我想要表達的傳達給大家
what it's like when we go snorkeling or diving
但讓我們也思考一下,作為擁有視覺的物種,
and try to look underwater.
當我們浮潛或潛水時,
We really can't see very far.
看看水下的世界時,它是什麼樣的?
Our vision, which works so well in air,
其實我們看不了多遠
all of a sudden is very restricted and claustrophobic.
在地表上我們的視覺良好
And what marine mammals have evolved
但突然間 我們會在水下受到嚴重的限制與幽閉
over the last tens of millions of years
而海洋哺乳動物
is ways to depend on sound
經過了近數千萬年來的進化後,
to both explore their world
牠們依賴聲音
and also to stay in touch with one another.
探索周圍的世界
Dolphins and toothed whales use echolocation.
並與其他同類保持聯繫
They can produce loud clicks
海豚和齒鯨使用回聲定位
and listen for echoes from the sea floor in order to orient.
牠們能產生響亮的喀喇聲
They can listen for echoes from prey
並傾聽海底反射的回聲來定位
in order to decide where food is
牠們能通過獵物所反射的回聲
and to decide which one they want to eat.
來確定牠們的食物在哪里,
All marine mammals use sound for communication to stay in touch.
並決定要吃什麽
So the large baleen whales
所有海洋哺乳動物用聲音來保持相互聯繫
will produce long, beautiful songs,
於是大型鬚鯨
which are used in reproductive advertisement
能發出悠長美麗的歌聲,
for male and females, both to find one another
這種歌聲被雌鯨和雄鯨用於尋求伴侶,
and to select a mate.
幫助牠們找到同類,
And mother and young and closely bonded animals
並且選擇配偶
use calls to stay in touch with one another,
呼叫的聲音也被用於母子之間的聯繫,
so sound is really critical for their lives.
或者在聯繫緊密的動物之間保持聯繫
The first thing that got me interested in the sounds
因此,聲音在牠們的生活中是非常重要的
of these underwater animals,
第一個引起我對這些海底動物的
whose world was so foreign to me,
聲音興趣的是,
was evidence from captive dolphins
這對我來說是個陌生的世界
that captive dolphins could imitate human sounds.
從捕獲的海豚中 所發現的證據表示:
And I mentioned I'll use
牠們能模仿人類的聲音
some visual representations of sounds.
我說我會使用
Here's the first example.
一些聲音的視覺化圖像
This is a plot of frequency against time --
這是第一個例子
sort of like musical notation,
這是幅頻率對時間的圖表--
where the higher notes are up higher and the lower notes are lower,
有點像音符,
and time goes this way.
高處的標記表示頻率較高,低處的標記表示頻率較低,
This is a picture of a trainer's whistle,
時間朝這個方向流逝
a whistle a trainer will blow to tell a dolphin
這張圖表示教練的哨聲,
it's done the right thing and can come get a fish.
這哨聲是教練用來告訴海豚
It sounds sort of like "tweeeeeet." Like that.
做對了 就能得到一條魚。
This is a calf in captivity
它聽起來有點像 “tweeeeeet”。有點像這樣。
making an imitation
這是一隻人工飼養的小海豚
of that trainer's whistle.
模仿的
If you hummed this tune to your dog or cat
教練的哨聲
and it hummed it back to you,
現在如果你對這你的貓貓或狗狗哼這個曲子,
you ought to be pretty surprised.
而牠也對著你哼這曲子,
Very few nonhuman mammals
你應該會大吃一驚。
can imitate sounds.
很少有除人類之外的哺乳動物
It's really important for our music and our language.
能模仿聲音
So it's a puzzle: The few other mammal groups that do this,
這種能力對我們學習音樂和語言十分重要。
why do they do it?
因此這讓人迷惑:少有其他哺乳動物能做到這點,
A lot of my career has been devoted
為什麼牠們能做到這點?
to trying to understand
我職業生涯中花了很多時間
how these animals use their learning,
試圖弄明白
use the ability to change what you say
這些哺乳動物如何運用牠們的學習能力
based on what you hear
運用此一能力:
in their own communication systems.
基於所聽到的改變所說的。
So let's start with calls of a nonhuman primate.
這些都在牠們自己的溝通系統中
Many mammals have to produce contact calls
那麼讓我們從非人靈長類的叫聲開始
when, say, a mother and calf are apart.
許多哺乳動物會發出呼喚聲
This is an example of a call produced by squirrel monkeys
比如說,當母親和幼兒分開時
when they're isolated from another one.
這是一個例子:這是松鼠猴
And you can see, there's not much
與其他同類分開時所發出的叫聲。
variability in these calls.
如你們所見,在這些叫聲中
By contrast, the signature whistle
沒有多少變化
which dolphins use to stay in touch,
相對地,海豚用於
each individual here has a radically different call.
保持聯繫的哨聲,
They can use this ability to learn calls
每一隻海豚都有完全不同的聲調
in order to develop more complicated and more distinctive calls
牠們用這種能力來學習叫聲,
to identify individuals.
以便能發展出更複雜、更獨特的聲納
How about the setting in which animals need to use this call?
來辨別不同的個體
Well let's look at mothers and calves.
在怎樣的環境下 動物必須使用這種叫聲?
In normal life for mother and calf dolphin,
好,讓我們看看母親和幼海豚
they'll often drift apart or swim apart if Mom is chasing a fish,
在海豚媽媽和海豚幼兒平常的生活中,
and when they separate
如果海豚媽媽去抓魚,牠們經常因為漂移或是游泳而分開
they have to get back together again.
當牠們分開時
What this figure shows is the percentage of the separations
必須重新聚在一起
in which dolphins whistle,
這張圖顯示,牠們分開時
against the maximum distance.
海豚發出哨聲的百分比,
So when dolphins are separating by less than 20 meters,
與此相對的是最遠距離
less than half the time they need to use whistles.
因此,當海豚分隔少於 20 公尺時,
Most of the time they can just find each other
低於半數的情況下,牠們需要用到哨聲
just by swimming around.
大多數時間,牠們四處遊動
But all of the time when they separate by more than 100 meters,
就能找到對方
they need to use these individually distinctive whistles
然而一旦牠們分開超過100公尺,
to come back together again.
牠們就需要使用這些各自獨特的哨聲
Most of these distinctive signature whistles
再次聚在一塊。
are quite stereotyped and stable
多數這類帶有獨特個別特徵的哨聲
through the life of a dolphin.
在海豚的一生中
But there are some exceptions.
都是定型的、而且非常穩定
When a male dolphin leaves Mom,
但也有些例外
it will often join up with another male
當雄海豚離開海豚媽媽時,
and form an alliance, which may last for decades.
牠通常會聯合另一隻雄海豚
As these two animals form a social bond,
形成一個聯盟,這一聯盟可能會持續幾十年之久
their distinctive whistles actually converge
由於這兩隻動物形成了一條社會紐帶,
and become very similar.
牠們獨特的哨聲實際上會進行融合
This plot shows two members of a pair.
變得非常相似
As you can see at the top here,
這張圖顯示了組合中的兩個成員,
they share an up-sweep, like "woop, woop, woop."
正如你們於頂部所看到的,
They both have that kind of up-sweep.
牠們有著同樣的上升調,像“woop,woop,woop“
Whereas these members of a pair go "wo-ot, wo-ot, wo-ot."
牠們都有這樣的上升調
And what's happened is
然而,另一對成員擁有的上升調是”wo-ot, wo-ot, wo-ot“
they've used this learning process
這是由於:
to develop a new sign that identifies this new social group.
牠們運用此一學習過程
It's a very interesting way that they can
發展出識別新社會群體的新信號
form a new identifier
這是非常有趣的方式,牠們可以
for the new social group that they've had.
為新的社會群體
Let's now take a step back
形塑一個新的識別標誌
and see what this message can tell us
現在讓我們退後一步
about protecting dolphins
看看這訊息能告訴我們些什麼
from human disturbance.
關於保護海豚
Anybody looking at this picture
遠離人類干擾的資訊
will know this dolphin is surrounded,
任何看到這張圖片的人都知道
and clearly his behavior is being disrupted.
這隻海豚被包圍了,
This is a bad situation.
顯然牠的行為被打亂了。
But it turns out that when just a single boat
這是個糟糕的情況。
is approaching a group of dolphins
但事實表明,
at a couple hundred meters away,
當僅有一艘船在數百公尺外
the dolphins will start whistling,
靠近一群海豚時,
they'll change what they're doing, they'll have a more cohesive group,
這些海豚會開始發出哨聲,
wait for the boat to go by,
牠們會放棄正在做的事,聚集成更大的群體,
and then they'll get back to normal business.
等待這艘船駛過,
Well, in a place like Sarasota, Florida,
然後回復正常
the average interval between times
嗯,在一個佛羅里達州 Sarasota 的地方,
that a boat is passing within a hundred meters of a dolphin group
一艘船在百公尺之內
is six minutes.
駛過一群海豚的 平均間隔時間
So even in the situation that doesn't look as bad as this,
是六分鐘
it's still affecting the amount of time these animals have
因此,即使在看起來不像這麼糟糕的情形下,
to do their normal work.
在多數時刻,仍然會對這些動物的
And if we look at a very pristine environment like western Australia,
正常生活造成影響
Lars Bider has done work
讓我們看看像澳洲西部這樣一個非常原始的環境,
comparing dolphin behavior and distribution
Lars Bider 曾經
before there were dolphin-watching boats.
比較了賞海豚的遊船產生之前和之後,
When there was one boat, not much of an impact.
當地海豚的行為與分佈
And two boats: When the second boat was added,
當只有一艘船時,對牠們的影響不大
what happened was that some of the dolphins
兩艘船時,當第二艘船駛來時,
left the area completely.
有些海豚
Of the ones that stayed, their reproductive rate declined.
完全離開了這一區域
So it could have a negative impact on the whole population.
留下的那些海豚的繁殖率下降了
When we think of marine-protected areas for animals like dolphins,
因此,這可能對整個群體數量產生負面影響
this means that we have to be
當我們考慮動物比如海豚建立海洋保護區時,
quite conscious about activities that we thought were benign.
這意味著我們也要
We may need to regulate the intensity
非常慎重地考慮那些我們認為無礙的活動
of recreational boating and actual whale watching
我們也許需要控制
in order to prevent these kinds of problems.
遊船的密度,甚至賞鯨船的密度,
I'd also like to point out that sound
以防類似問題的發生
doesn't obey boundaries.
同樣,我想指出那些
So you can draw a line to try to protect an area,
沒有辦法設置防線的因素:聲音
but chemical pollution and noise pollution
你可以畫一條線,試圖保護一個區域,
will continue to move through the area.
但是化學污染和噪音污染
And I'd like to switch now from this local,
將不斷進入這一區域。
familiar, coastal environment
現在,我想從這種地方性的、
to a much broader world of the baleen whales and the open ocean.
為人熟知的沿海環境轉換至
This is a kind of map we've all been looking at.
鬚鯨的更廣闊的大海
The world is mostly blue.
我們經常看到這類地圖
But I'd also like to point out that the oceans
世界大部分是藍色的
are much more connected than we think.
但我還想指出的是,海洋之間的
Notice how few barriers there are to movement
聯繫地比我們所想像的更加緊密。
across all of the oceans compared to land.
請注意,相較於陸地而言,對海洋間的