Skip to content
NatureHQ

Claim check

Can crows recognise human faces?

Mostly supported

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

Yes, in a specific and well-evidenced sense. Wild American crows learn a particular human face associated with being caught, remember it for years, and pass the association to birds that were never caught themselves. The "grudge" part is a human word for behaviour the experiments cannot see inside.

The claim as it circulates

“Crows never forget a face, and will hold a grudge against anyone who wrongs them.”

Where you may have met it: Viral social media posts about crows leaving gifts; Documentary segments on corvid intelligence; Newspaper science coverage of the Seattle mask experiments

Taking it apart

What was claimed
That crows recognise individual people, remember them indefinitely, and act on that memory — often framed as holding a personal grudge.
What was actually observed
Researchers wore a rubber mask while catching and ringing wild American crows. Afterwards, different people wearing that same mask were scolded and mobbed along fixed routes, while a neutral mask was largely ignored. The response persisted for years and spread to birds that had never been caught.
What the evidence supports
That American crows discriminate between human faces, attach a specific meaning to one, retain it for at least five years, and transmit it socially through the population. Brain imaging shows threatening and caring faces engaging different circuitry.
What it does not support
That crows perceive faces the way people do, that they would notice someone who has never done anything to them, or that anything resembling a grudge is involved. The experiments measured alarm behaviour: they show the birds told faces apart, not what they felt or which features they used. The research is on American crows; European carrion and hooded crows have not been tested the same way.

The reason this result is trusted is a detail that rarely survives into the coverage: the masks were passed between people of different heights and builds, wearing different clothes. If the birds had been tracking a person, that would have broken the effect. They were tracking the face.

Go deeper

The claims underneath

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

Crows can recognise individual human faces

Well supported

Good evidence backs this, though some details remain open.

Wild American crows (Corvus brachyrhynchos) discriminate between human faces and associate a specific face with threat, responding to that face independently of the body wearing it.

Who this applies to
American crows, in the wild
Studied in
Corvus brachyrhynchos

You may have heard

“Crows never forget a face, and will hold a grudge against you personally.”

The research is about a face linked to a genuinely threatening event — being caught and handled — and about a species studied in North America. Nothing suggests a crow forms an opinion of a person who has simply walked past, and "grudge" describes a human motive the experiments cannot detect.

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

The mask design rules out the obvious alternatives — different people wore the same face — and the effect was replicated across sites, persisted for years, and has a matching brain-imaging result.

How far it can be extended

Comparable face and person discrimination has been reported in other corvids and in several unrelated urban birds, and the ability fits the ecology of any long-lived bird living alongside people. It has not been demonstrated experimentally in most Corvus species, so it remains an expectation rather than a finding.

Caveats

  • Demonstrated with masks, which are exaggerated and unmoving compared with a real face.
  • The measure is alarm behaviour, so it shows the birds told faces apart — not which features they used.
  • Shown in American crows; carrion crows, hooded crows and rooks have not been tested the same way.

Still unanswered

  • Which facial features do crows actually use?
  • Do crows recognise faces they associate with something positive as reliably as threatening ones?

Last reviewed 2026-08-09

The evidence (2 studies)

Crows remember a threatening person for years

Well supported

Good evidence backs this, though some details remain open.

American crows continued to respond defensively to a mask associated with capture for at least five years after the original event, with no reinforcement in between.

Who this applies to
American crows
Studied in
Corvus brachyrhynchos
Why we rate it this way, and what the caveats are
Well supportedHigh confidence

Tracked across multiple sites over several years by the same team using a consistent protocol, with the response persisting rather than fading.

Caveats

  • Because the response spread socially, some later scolding came from birds reacting to other birds rather than from personal memory.
  • Individual birds were mostly unmarked, so the duration is a population-level observation.

Still unanswered

  • How long does an individual crow retain the association without seeing others react?

Last reviewed 2026-08-09

The evidence (2 studies)

Crows tell each other about dangerous people

Well supported

Good evidence backs this, though some details remain open.

Defensive responses to a specific human face spread through American crow populations to individuals with no direct experience of the threatening event, including juveniles born afterwards.

Who this applies to
American crows
Studied in
Corvus brachyrhynchos
Why we rate it this way, and what the caveats are
Well supportedModerate confidence

The spread is well documented across five years and several sites. Whether it happens through deliberate signalling or by simply observing other birds mob is not resolved, and "tell" is a convenient shorthand rather than a description.

Caveats

  • Transmission was inferred from how the response spread, not observed between named individuals.
  • Learning by watching a mobbing crowd is a simpler explanation than intentional communication, and fits the data.

Still unanswered

  • Is there a specific signal, or do birds simply learn by joining a mob?
  • How accurately is the identity of the dangerous face preserved as it spreads?

Last reviewed 2026-08-09

The evidence (2 studies)

Go deeper

Crows

They know your face. What that actually means is more specific — and more interesting — than the headline.

Last reviewed 2026-08-09