Most animals give away who is calling the way a voice does, through the texture one body imposes on every sound it makes. Bottlenose dolphins do something else, because each animal produces a distinctive whistle type of its own. Janik and Sayigh gathered fifty years of work on those whistles into one review. How far does the comparison with a name actually go?
Further than you would expect. The identity sits in the pattern of a distinct whistle type, not in a voice texture smeared across every call. A young dolphin takes a whistle from its surroundings as a model and then alters it, inventing a new signal rather than copying one. Dolphins also copy another animal’s at low rates, which effectively addresses the owner.
Plenty of animals tell each other apart by sound. Usually the cue is voice, meaning the resonances of one body coloring everything it says, the way you recognize a friend saying anything at all. The caller is not choosing to identify itself, and could not choose otherwise.
Bottlenose dolphins work the other way round. Each animal has a signature whistle, a distinct whistle type whose identity information lives in its frequency modulation pattern, the shape the pitch traces over time. That is a signal with a form, separable from the animal making it.
The developmental story is what makes the comparison bite. Signature whistle development involves : a young dolphin uses a whistle from its environment as a model, modifies it, and arrives at a novel signal. Dolphins also copy the whistles of others, at low rates, and the copies stay recognizable as copies.
Whether any of that amounts to a name is the question the review leaves standing. Captive dolphins can learn to associate new whistles with objects, then use those whistles to report whether the object is there. If the same ability extends to signature whistles, these would be a rare example of a learned in an animal.
wat. Invented rather than inherited, and copied back at its owner, which lands closer to a name than to a voice.
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A signal an animal invents for itself, and that others can use to address it, is a far stronger claim about communication than recognizing a familiar voice.
How do we know?
Janik and Sayigh reviewed fifty years of signature whistle research, covering acoustic features, information content, development, and how these calls compare with recognition calls in other animals.
What is still unknown
A review rather than one experiment, and its strongest claim stays conditional: the referential use was shown with novel whistles learned in captivity, not with signature whistles themselves.
Learn something?
Where to next
What do elephants hear through the soles of their feet?communication
Do elephants call each other by name?communication
Can a flower hear a bee coming?sound