'Dolphins Know Each Other's Names'

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Please continue to fight for the protection of Dolphins in Japan!

~Kim, Okinawa Voices4Animals

 

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The Sunday Times May 07, 2006

 

 

Dolphins `know each other's names'

Jonathan Leake, Science Editor

 

Whistles are used for individual recognition

 

 

 

 

DOLPHINS may be closer to humans than previously realised, with new

research showing they communicate by whistling out their

own " names " .

 

The evidence suggests dolphins share the human ability to recognise

themselves and other members of the same species as individuals with

separate identities. The research, on wild bottlenose dolphins, will

lead to a reassessment of their intelligence and social complexity,

raising moral questions over how they should be treated.

 

The research was carried out by Vincent Janik of the Sea Mammal

Research Unit at St Andrews University, who has found bottlenose

dolphins to be among the animal world's quickest learners of new

sounds.

 

He said: " Each animal develops an individually distinctive signature

whistle in the first few months of its life, which appears to be

used in individual recognition. "

 

The research has its origin in the 1960s when dolphin trainers first

noticed that captive animals each had their own personal repertoire

of whistles.

 

This prompted speculation that dolphins had their own language and

might even have individual " names " . However, the theory was

controversial among whale and dolphin researchers, and until now,

there had been no means of testing it.

 

Janik's work was based on a group of dolphins living in Sarasota

Bay, Florida, who have been studied for more than 30 years. Over

that time researchers have built up a detailed picture of individual

dolphins, their family ties and their " social " interaction.

 

They have also made extensive recordings of the noises made by

individual dolphins and isolated the sounds thought to be

their " signature whistles " or names.

 

In the study some of the Sarasota Bay animals were corralled in a

net. The researchers then played synthetic versions of the signature

whistles of other dolphins through underwater loudspeakers to see if

they would evoke a response in the captive animals. The use of

synthetic whistles ruled out the possibility that the animals might

simply be recognising the sound of each other's voices.

 

They found that dolphins responded strongly to the whistles of their

relatives and associates while generally ignoring those of dolphins

to whom they had no link.

 

Janik said: " Bottlenose dolphins are the only animals other than

humans to have been shown to transmit identity information

independent of the caller's voice. "

 

The findings are supported by other authorities. Denise Herzing,

research director at the Wild Dolphin Project at Florida Atlantic

University, said it was already clear that many of the 77 known

cetacean (whale and dolphin) species had rudimentary languages.

 

" We know that dolphins' brains are nearly as large and complex,

relative to body size, as those of humans. They have evolved to be

intelligent and that implies being able to communicate, " she said.

 

Dolphins may, however, be just the first of many species where

individuals are found to have their own names. Other researchers

have already found evidence for highly developed language skills in

parrots, crows and primates.

 

Great apes, such as chimpanzees and orang-utans, have been a popular

subject for research because they are so closely related to humans.

 

Their limited vocal apparatus means they cannot speak but

researchers at Georgia State University have taught chimpanzees to

communicate in English via computers equipped with customised

keyboards and voice synthesizers.

 

The African grey parrot is another renowned linguist, able not only

to learn words but to use them in the right context.

 

Even some rodent species may have developed a rudimentary language.

Con Slobodchikoff of Northern Arizona University recently found that

prairie dogs, a large rodent found in the western United States,

shared a language of at least 100 words.

 

Donald Broom, professor of animal welfare at Cambridge University,

said species living in large groups all had advanced communication

skills. " They have a complex social structure where they have to

live with others, negotiate friendships and find mates. If dolphins

are using names I expect we will find the same in other species with

similar lifestyles. "