Skip to content
NatureHQ

Claim check

Do dolphins have names for each other?

Mostly supportedThe core is right; the usual phrasing overstates part of it.

Closer than you would expect, and not quite. A dolphin invents a whistle for itself as a calf and keeps it for life, others recognise the pattern with the voice stripped out, and dolphins copy each other’s whistles when separated. What has not been shown is one dolphin using another’s whistle to talk about it to a third.

The claim as it circulates

“Dolphins give each other names and call each other by them.”

Where you may have met it: Science news coverage of the signature whistle experiments; Popular writing on animal language; Aquarium and marine park interpretive material

Taking it apart

What was claimed
That dolphins use names in the human sense — arbitrary labels given to individuals and used to refer to them.
What was actually observed
Bottlenose dolphins develop an individually distinctive whistle contour in the first year and retain it for decades. Played a synthetic reproduction of a relative’s contour with all voice characteristics removed, wild dolphins turned towards the speaker significantly more often than for control contours. Separately, dolphins were found to copy the signature whistles of close associates, and to do so most when the two were apart.
What the evidence supports
That identity is carried by a learned, arbitrary pattern rather than by voice — which is the property a name has and a voice does not. That dolphins address specific individuals with those patterns.
What it does not support
Reference to an absent third party, which is the other half of what a name does. And the label is self-produced rather than given, so a signature is a better analogy than a name. The decisive experiments used fourteen temporarily restrained animals from one long-studied population.

The voice-stripping is what makes this result strong, and it is almost always left out of the coverage. Recognising a friend by voice is unremarkable and every social mammal does something like it. Recognising them by an arbitrary tune they invented for themselves, with the voice removed, is a different order of thing.

NatureHQ marks this mostly-supported rather than exaggerated because the surprising part of the popular claim is the part that holds. The gap is narrow and specific, and naming it precisely is more useful than either endorsing or dismissing the headline.

How we know

Calling a dolphin by its own name, in somebody else’s voice

When a dolphin hears its own signature whistle, is it recognising the whistle, or recognising the voice of whoever produced it?

Each animal’s signature whistle was resynthesised — the contour preserved, the voice characteristics that identify the producer stripped out. That synthetic version was played back to the animal, alongside two controls: the synthesised signature whistle of a familiar animal from the same group, and that of an animal it had never met. Whether the subject whistled back was recorded.

What happened

Dolphins answered playbacks of their own whistle and did not answer either control.

What it shows

The contour by itself is enough for a dolphin to recognise that it is the one being addressed. That makes the whistle a learned, arbitrary, individually specific label with a receiver who responds to it — the strongest evidence for a language-like property in any animal signal.

What it does not show

It does not show that dolphins use each other’s labels the way people use names. Nothing here involves one dolphin referring to a third animal that is not present, which is the property that would make it displacement. Copying another animal’s whistle happens mostly between mothers and calves and between allied males rather than across a population, so this is not a general addressing system. The sample is small and the animals were temporarily restrained.

The controls — what makes this evidence rather than a story
  • Voice features removed, so a response cannot be recognition of who is speaking.
  • A familiar animal’s whistle as a control, which rules out a general response to anything familiar.
  • An unfamiliar animal’s whistle as a second control, which rules out a general response to any whistle.

From Bottlenose dolphins can use learned vocal labels to address each other

Worth setting beside the elephants, because the two animals credited with names do it differently. A dolphin addresses another by copying that animal’s own whistle — an imitation of the addressee. African elephants appear not to copy anything, which makes their label arbitrary in a way a signature whistle is not, and arbitrariness is exactly what makes a human name a name.

Go deeper

The claims underneath

Each one carries its own evidence, scope and caveats. Expand any of them to reach the studies.

Each dolphin invents its own whistle, and others recognise it

Well supported

Good evidence backs this, though some details remain open.

Bottlenose dolphins develop an individually distinctive frequency contour during the first year of life and retain it for decades. Conspecifics respond to a synthetic reproduction of that contour with all voice characteristics removed, showing that identity is carried by the learned pattern itself rather than by vocal timbre.

Who this applies to
bottlenose dolphins, principally the long-studied Sarasota Bay population
Studied in
Tursiops truncatus

You may have heard

“Dolphins have names for each other”

A signature whistle is self-produced — closer to a signature than to a name given by others — and while dolphins copy each other’s whistles when separated, using a whistle to talk *about* an absent dolphin has not been shown. The learned, arbitrary, individual-specific part of the analogy holds; the naming part does not.

Why we rate it this way, and what the caveats are
Well supportedHigh confidence

The voice-stripped playback design rules out the obvious alternative — that dolphins simply recognise each other’s voices — and the developmental work showing whistles are invented young and kept for life comes from an independently tracked wild population.

How far it can be extended

Signature-whistle-like individually distinctive calls have been reported in other delphinids, though the voice-stripped playback test has been run on bottlenose dolphins.

Caveats

  • Small samples of temporarily restrained wild animals in the decisive experiments.
  • Most evidence comes from one intensively studied population that may not be typical.
  • Copying a whistle when separated is consistent with addressing an individual and does not demonstrate reference to an absent third party.

Still unanswered

  • Do dolphins use another individual’s signature whistle to refer to it in that individual’s absence?
  • How much additional information beyond identity does a whistle carry?

Last reviewed 2026-08-09

The evidence (3 studies)

Each bottlenose dolphin develops its own whistle, others learn to copy it, and a dolphin answers when its own whistle is played back.

Established

Specialists would state this without hedging. Multiple independent lines of evidence agree.

Bottlenose dolphins develop individually distinctive signature whistles within the first months of life and retain them for decades. Playback of a synthesised copy of an animal’s own signature whistle, with voice characteristics removed, elicits a vocal response, while playbacks of familiar and unfamiliar animals’ whistles do not.

Who this applies to
Demonstrated in bottlenose dolphins. Signature-whistle-like signals are reported in a few other delphinids but are far less well characterised.
Studied in
Tursiops truncatus
Why we rate it this way, and what the caveats are
EstablishedHigh confidence

Fifty years of observational work established the whistles; the playback experiment established that the contour alone is enough for an animal to recognise it is being addressed. Both halves have been independently replicated.

How far it can be extended

The experimental work is almost entirely on one species and on a small number of intensively studied populations.

Caveats

  • Copying happens mostly between close associates — mothers and calves, allied males — rather than across a population.
  • A dolphin responding when addressed is not the same as a dolphin talking about a third animal that is not there.

Still unanswered

  • Whether a dolphin can use another’s whistle to refer to it in its absence.
  • What, if anything, is added to the whistle beyond identity.

Last reviewed 2026-08-31

The evidence (3 studies)

Several animals have one or two of the things that make human language what it is. Nothing has been shown to have the whole set.

Well supported

Good evidence backs this, though some details remain open.

Individual design features associated with human language — learned arbitrary labels, functionally referential signals, combinatorial structure, cultural transmission of form — are separately documented in non-human species. No non-human system has been demonstrated to combine open-ended productivity, syntactic structure carrying meaning, and displacement.

Who this applies to
Concerns natural communication systems. Claims about apes trained on human symbol systems are assessed separately and on their own evidence.
Studied in
Animalia

You may have heard

“Scientists have discovered that animals have language.”

Each discovery of this kind is a discovery of one property. Learned labels in dolphins, name-like calls in elephants, structure in sperm whale codas — all real, all genuinely surprising, and none of them the full set. The headline collapses "has a property of language" into "has language", and the two are separated by the properties nobody has found.

Why we rate it this way, and what the caveats are
Well supportedModerate confidence

Confidence is moderate rather than high because this is partly an argument from absence, and because the properties in question are hard to test in the wild. What supports it is that the best-studied systems have been examined specifically for these properties and have not shown them.

How far it can be extended

The absence is across everything examined so far; it is a statement about the current evidence rather than about what is possible.

Caveats

  • This is not a claim that animals are simple, or that their systems are worse. A signal that does exactly what the animal needs is not a failed language.
  • Absence of evidence is doing real work in this claim, and displacement in particular is close to untestable in a wild animal.
  • Every year or two a system is reported to have one more of these properties, and that trend may continue.

Still unanswered

  • Whether any animal can refer to something that is not present — the property that is both most diagnostic and hardest to test.
  • Whether the design-feature framework, built from human language, is the right way to describe systems that evolved for other purposes.

Last reviewed 2026-08-31

The evidence (4 studies)

  • Supports · primary

    Can an ape create a sentence?

    Terrace et al., 1979 · Science

    The most direct test of syntactic productivity in a non-human, and it did not survive frame-by-frame analysis of who signed first.

  • Context · supporting

    Contextual and combinatorial structure in sperm whale vocalisations

    Sharma et al., 2024 · Nature Communications

    The strongest current case for combinatorial structure in a natural system — and it identifies structure without identifying meaning or testing a receiver.

  • Qualifies · supporting

    Bottlenose dolphins can use learned vocal labels to address each other

    King and Janik, 2013 · Proceedings of the National Academy of Sciences

    Shows one language-like property genuinely present: learned, arbitrary, individually specific vocal labels that receivers respond to.

  • Qualifies · supporting

    Prairie dog alarm calls encode labels about predator colors

    Slobodchikoff et al., 2008 · Animal Cognition

    The origin of "prairie dogs have a language". The acoustic finding — that calls vary with an intruder’s size, shape and even shirt colour — is real and replicated. What is much thinner is the receiver work needed to show that other prairie dogs extract those distinctions, which is what would make the variation descriptive rather than merely present.

Go deeper

Dolphins

A dolphin invents its own whistle as a calf and answers to it forty years later — even when the voice is stripped out.

Related things people ask

Last reviewed 2026-08-31