[自然百科] 海豚都有名,並會響應自己的名!

colourbeast

We already knew that bottlenose dolphins can follow "recipes" in preparing mollusks, help other species in distress, and possibly do math. So it may come as no surprise that the marine mammals also call each other by whistles that act as names.

Past studies have shown that individual dolphins have a unique whistle, called a "signature whistle," that they often use in big group settings, like when several pods of dolphins meet at sea.

The idea that dolphins have a name in the form of a whistle has been around since the 1960s, and studies of captive dolphins have shown that the animals are responsive to the whistles of dolphins they know.




But a new study takes the theory a step further by asserting that a dolphin will respond when it hears the sound of its own signature whistle, repeating that whistle back in a way that seems to say, "Yup, I'm here—did you call my name?" explained Whitney Friedman, a dolphin-behavior expert at the University of California, San Diego.

It's "compelling evidence" that the dolphin indeed uses the sound as a name, according to the study, published July 22 in the Proceedings of the National Academy of Sciences.

The research was performed by a group of scientists on a boat off eastern Scotland who joined up with a group of wild dolphins. When one of the dolphins announced itself with its signature whistle—the equivalent of "Joey!" for instance—the researchers recorded that sound.



Later, the team played that same "Joey!" call back to the dolphins, and a significant portion of the time, the dolphin they called Joey responded with the same call—as if Joey was saying, "Yup, I'm here."

The dolphins responded a little when the scientists played recordings of whistles of familiar dolphins from the same population, but did not respond at all to unfamiliar dolphins from a different population. (Watch video: "Dolphin Talk Decoded.")

The finding shows that signature whistles aren't just noises dolphins produce, but also signals to which they respond—a "fantastic contribution" toward understanding how dolphins communicate, said Friedman, a National Geographic grantee who was not part of the new study.

Gossiping Dolphins?




The finding is more evidence that identity is important for dolphins, which form complex relationships within tight-knit communities.

For instance, being able to call a dolphin by name could be crucial in a situation where a competition erupts between two groups of male dolphins and a member of one group is missing. One of the dolphin groups could call the missing dolphin's signature whistle to request that he help out, noted Friedman.

What's more, the ocean is noisy and visibility is poor, so there's a greater need for sounds that indicate an animal's identity, said Jeremy Karnowski, also a UCSD dolphin-communication expert who was not involved in the new study.

"Having sounds that express identity might be a way for the group to know where each group member is at a given time, and the specific identity of that dolphin," he said.

Building on this study, scientists could look at the two other types of dolphin vocalizations, Karnowski said by email.

One is the "clicks" dolphins make during echolocation—the use of built-in sonar that helps dolphins find prey—and the other is "burst-pulse" calls that sound like buzzing and squeaking. (See "The Secret Language of Dolphins.")




These "other vocalizations might have meanings," he said.

The study also raises other questions, like exactly when and how often dolphins address each other, Karnowski said. Perhaps most intriguing: Do dolphins use these names to talk about each other behind their backs?

Source: NG

非常聰明!

vandas

[轉貼]海豚怎麼聊天？

「喂、吃飽沒？」人在聊天的時候會喊喂，或者是叫名字引起對方的注意力。就像人類用名字來彼此呼喚，學者懷疑海豚也能使用特定的哨聲呼喚別隻海豚。

早前的研究發現，海豚很常發出某些特定的口哨聲，在同一個團體行動的海豚甚至可以學習並複製這些特定哨聲。但近來第一次有研究指出，這些特定哨聲很有可能是海豚的名字。BBC 22號報導，聖安德魯大學從事海生哺乳動物研究的傑尼可博士(Vincent Janik)表示，海豚居住在廣闊的海洋，在這樣廣大遼闊的居住環境，讓他們需要一個有效率的方法來保持聯繫，而用名字來呼喚彼此就是他們所發展出的溝通方法。

研究的方法
為了調查，蘇格蘭聖安德魯大學研究團隊追蹤一群野生的瓶鼻海豚(bottlenose dolphin)，記錄每隻海豚重覆發出的哨音，然後用水底麥克風播放錄下的哨聲。傑尼可博士說，研究團隊播放的哨聲有三種，第一種是團隊追蹤的瓶鼻海豚群所重複發出的特定哨聲；第二個是該群體較少發出的其他哨聲；最後是另一個海豚群所反覆出現的特定哨聲。

研究結果發現，海豚只有在聽到某個特定哨聲，才會發出口哨聲回應。因此學者推測，這些特定哨聲就像人類的名字一樣，發出哨聲就像是在叫海豚的名字，會讓他們有所回應。

用名字溝通的原因
傑尼可博士推測，海豚擁有這項技能可能是因為海洋的範圍太遼闊，大部分的時候海豚看不到彼此，在海裡也不能像其他的哺乳動物一樣用嗅覺來辨認，再加上海豚不習慣待在一個定點會合聚集，因此海豚發展出一個溝通系統，來幫助他們群聚在一起。

傑尼可博士認為藉由研究不同種動物的溝通技能演化，可以幫助我們更進一步了解人類在交流通訊上是如何發展的。研究論文刊載於美國國家科學院院刊(PNAS)。

tvbkk123

之前看過一篇新聞報導，某國家訓練海豚抓人