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Vocal mimicry

A courting male lyrebird does not imitate a bird. It imitates an entire mobbing flock — several species and their wingbeats — at one specific moment in the display.

Some birds copy sounds made by other species, and occasionally by machines. Why is much less settled than the ability is impressive — the best-evidenced case, a lyrebird imitating an entire mobbing flock during courtship, suggests the copy can be doing something quite specific rather than merely showing off.

Vocal mimicry sits awkwardly inside the rest of song learning. Most songbirds arrive with a strong bias towards copying their own species and ignore the rest of the wood; mimics have very little of that filter, and some of them will take on anything, including chainsaws and camera shutters. The ability follows straightforwardly from vocal learning — a bird that can copy a song can copy a sound — so the interesting question is not how but why, and the answers proposed are numerous and mostly under-tested. Repertoire size as a sexually selected display is the usual explanation, and it fits the fact that mimicry is often concentrated in male song. Deterring predators or rivals by producing an alarming sound is another, and it has good support in some contexts. Simple learning error — copying whatever is around because the filter is weak — cannot be dismissed and is rarely tested against. What lifted the subject out of anecdote was a 2021 study of superb lyrebirds, which found males producing not one imitation but a structured composite: several species’ alarm calls together with imitated wingbeats, assembled into something resembling a mixed-species mobbing flock, and produced specifically during courtship and copulation. That is a copy of a scene rather than a sound, deployed at a particular moment, and it moves the discussion from "look what it can do" to "what is it for". The functional interpretation is still inference from timing; nobody has tested what a female does when she hears it.

Developed coverage · 62% complete · reviewed 2026-09-02

What this page covers

Vocal mimicry is scattered through the songbirds and parrots. Lyrebirds, mockingbirds, starlings and marsh warblers are the well-studied cases, and they are unusual even among mimics.

Often confused with: Batesian and Müllerian mimicry, which are about appearance and defence and have nothing to do with this; A parrot repeating human speech, which is mimicry and is usually discussed as though it were something else

Quick facts

How it is possible
Vocal learning without the usual species filter
The best-evidenced case
Lyrebirds assembling an acoustic mobbing flock during courtship
Why they do it
Several hypotheses; very few discriminating experiments

Where this appears

Every organism below has been linked to this page because the evidence links them. Each one carries its own evidence, and its own limits.

A copy, with the filter turned off

Mimicry is not a separate ability. It is ordinary vocal learning without the species bias.

A young swamp sparrow tutored with a mixture of its own and another species’ syllables takes its own and leaves the rest — an innate perceptual bias that stops a bird in a crowded wood copying the wrong thing. Mimics have far less of that bias, and once it is weak the same learning machinery that acquires a song will acquire anything with the right acoustic properties. So mimicry needs no special mechanism, which is why it turns up in scattered lineages rather than in one branch, and why the interesting question is what it is for.

The filter mimics do not have.

A young bird in a wood full of singers copies almost none of them: it arrives with a bias about which sounds are worth memorising.

Well supported

Good evidence backs this, though some details remain open.

Song learning in several songbird species is guided by an innate perceptual predisposition favouring conspecific acoustic material. In tutoring experiments with constructed songs, learners select conspecific syllables largely independently of the temporal pattern in which they are presented.

Who this applies to
Demonstrated in a small number of sparrows; the strength of the bias varies greatly across songbirds and is nearly absent in mimics.Do not extend this beyond the taxa listed — the popular version over-reaches.
Studied in
Melospiza georgiana, Melospiza melodia, Zonotrichia leucophrys
Why we rate it this way, and what the caveats are
Well supportedHigh confidence

The crossed design — syllable type against temporal pattern — is a strong test, and the result replicates. The confidence attaches to the species tested rather than to songbirds as a whole.

How far it can be extended

Starlings, lyrebirds and mockingbirds copy heterospecific and non-biological sounds extensively, so a strong species filter is a feature of some songbirds rather than of songbirds.

Caveats

  • Tape tutoring understates what a bird will learn; social context weakens the filter substantially.
  • The acoustic features the bias is tuned to have not been isolated.
  • Vocal mimics demonstrate that the filter can be nearly absent within the same clade.

Still unanswered

  • How a predisposition tuned to species-typical sound coexists with mimicry in close relatives.

Last reviewed 2026-09-02

The evidence (3 studies)

It is worth noting how good the copies are and are not. A skilled mimic reproduces the spectral shape of a model closely enough to fool a listener of the mimicked species in playback; it usually does not reproduce the amplitude, the duration or the full sequence. Recordings of a lyrebird "imitating a chainsaw" are real and are also, in the wild, rare — most of what a lyrebird copies is other birds.

The one result that changed the question

Not a copy of a sound. A copy of a situation, at a specific moment.

A male lyrebird courting a female imitates not one bird but an entire mobbing flock — several species’ alarm calls and their wingbeats — at a specific moment in the display.

Emerging evidence

Real findings exist, but too few or too recent to be settled.

Male superb lyrebirds produce a structured mimetic sequence resembling a mixed-species mobbing flock, including heterospecific alarm calls and imitated wingbeats, specifically during courtship and copulation. The functional interpretation is that the sequence deters the female from leaving.

Who this applies to
One population of one species, from acoustic analysis of wild displays.
Studied in
Menura novaehollandiae
Why we rate it this way, and what the caveats are
Emerging evidenceModerate confidence

The acoustic description is solid and the timing is striking. The functional claim rests on when the display occurs rather than on any manipulation, and no playback has tested what a female does.

Caveats

  • Observational: the proposed function is inferred from timing, not demonstrated.
  • What the female perceives, and whether she is deterred, is untested.
  • Lyrebirds are the extreme case of vocal mimicry rather than a representative one.

Still unanswered

  • Whether females respond to the sequence as they would to a real mobbing flock, which a playback experiment could answer.

Last reviewed 2026-09-02

The evidence (1 study)

The interpretation offered — that the illusion of danger discourages the female from leaving at the moment she is most likely to — is inference from when the display occurs. It is a strong inference and it is not a demonstration. The experiment that would settle it is a playback: present the sequence to a female and see whether she behaves as she would towards a real mobbing flock. Until somebody runs it, this is the best-described piece of mimicry anywhere and its function remains a hypothesis.

The standard this would have to meet

Diagram

Not one bird copied — a scene assembled

Schematic. The number of components and their order are illustrative.

Not one bird copied — a scene assembledSchematic. Component count and order are illustrative.Alarm call, species oneAlarm call, species twoAlarm call, species threeImitated wingbeatsA mixed-species mobbing flockthat is not there, produced duringcourtship and copulation.The proposal: it deters the femalefrom leaving.An interpretation, not ademonstrated function.
The same explanation in words

Four labelled boxes on the left — the alarm calls of three different species, and imitated wingbeats — each with an arrow pointing into a single box on the right. That box reads: a mixed-species mobbing flock that is not there, produced during courtship and copulation. Beneath it, two lines state the proposal that the sequence deters the female from leaving, and then, in a warning colour, that this is an interpretation rather than a demonstrated function.

Why copy anything at all

Several answers, none of them established across mimics generally.

The proposed functions, and how far each has been tested. They are not exclusive.
ExplanationThe ideaEvidence
Repertoire displayCopying inflates the size and variety of a song, which may be what females attend to.Fits the concentration of mimicry in male song; direct tests of female preference are scarce.
DeterrenceProducing a predator or alarm sound drives off a rival or a nest predator.Supported in specific contexts, including the lyrebird courtship case.
Weak filterThe bird copies what is around because it lacks the bias that stops other songbirds.Rarely tested against, and it is the explanation any functional account has to beat.

The third row is the one usually skipped. A behaviour that follows from the absence of a constraint does not automatically have a function, and a field that finds mimicry striking is disposed to look for one. Nothing here says mimicry is functionless — the lyrebird result argues strongly that at least sometimes it is not — but the null hypothesis deserves to be stated rather than assumed away.

And the mimic everybody has met

A parrot repeating a phrase is doing exactly what a starling copying a car alarm is doing: vocal production learning applied to a sound outside its own species. It feels different because the sound happens to be language, and that difference is entirely in the listener. Whether a parrot can also attach meaning to what it produces is a separate question with a separate and much smaller evidence base.

Kept apart on their own page

Claims about this, checked

Things people have heard, and what the evidence actually supports.

The research behind this page

4 studies, newest first. Each one has a page explaining what it found and what it could not show.

2021Current Biology

Male lyrebirds create a complex acoustic illusion of a mobbing flock during courtship and copulation

Males produced a mimetic sequence closely resembling a mixed-species mobbing flock — several species’ alarm calls together with imitated wingbeats — specifically at moments during courtship and while copulating.

2009Nature

De novo establishment of wild-type song culture in the zebra finch

Song moved towards wild-type structure at every generation, and within three to four generations the colony was singing song statistically indistinguishable from wild-type on the measured features.

1984Animal Behaviour

Social interaction, sensitive phases and the song template hypothesis in the white-crowned sparrow

Birds tutored by live models learned songs at ages at which tape tutoring no longer worked, and some learned the song of the other species when the tutor was live — an outcome tape tutoring essentially never produced.

1977Science

Selective vocal learning in a sparrow

The young birds learned syllables of their own species and largely ignored the other species’ syllables, regardless of which temporal pattern the syllables were embedded in.

Where to go from here

Each of these follows from something on this page — a relationship in the evidence, a claim people ask about, or the next mechanism along.

How complete this page is, and what it is still missing

NatureHQ publishes its own gaps. This page is at 62% completeness against what we would call a finished subject, and was last reviewed on 2026-09-02. It carries 2 claims and answers 22 mapped search questions.

  • 12 high-priority search intent(s) not yet covered
  • Only one mimic is covered in any depth. Mockingbirds, marsh warblers and starlings are named and not described.
  • Brood-parasite mimicry and mimicry of predator calls by non-passerines are absent.
  • The relationship between mimicry and repertoire-based sexual selection is summarised in a table rather than assessed.