Photo: Gordon Leggett · CC BY-SA 4.0
Faces
Crows can recognise individual human faces and remember the people who treated them badly.
5 min readLast updated
The short answer
Yes. Studies at the University of Washington showed American crows can recognise individual human faces, remember people who threatened them for years and even teach other crows to avoid those people.
Why it's true
In 2006, wildlife biologist John Marzluff and his team trapped and banded crows on their Seattle campus while wearing a distinctive caveman mask. Afterwards, people walking the campus wearing the same mask were mobbed and scolded by crows, while people wearing a different, neutral mask were mostly ignored.
The reaction lasted for years and spread. Crows that had never been trapped also began scolding the dangerous mask, suggesting they learned from other crows. The number of birds reacting grew over time, rather than fading. Later brain imaging studies by the same team showed crows used brain regions linked to fear and learning when they saw the threatening face.
The work suggests crows pay close attention to people and remember who matters to them.
By the numbers
2006
Seattle mask experiment begins
Years
How long crows remembered the mask
2010
Results published in Animal Behaviour
40+
Species in the crow genus Corvus
How we know
The mask design was clever. By using masks rather than real faces, researchers could test whether crows were reacting to the face itself, not to clothing, walk or other clues. Volunteers wore the dangerous and neutral masks on set routes and counted how many crows scolded them.
Results were published in the journal Animal Behaviour in 2010, and follow up papers tracked the reaction for years. Marzluff described the findings in popular books on crows, and similar face recognition has since been found in other birds, such as magpies and pigeons, showing that recognising people may be a useful skill for animals that live alongside us.
Inside the crow brain
Using brain scans, the Seattle team found that seeing the dangerous mask activated regions linked to fear and memory, similar to how mammal brains respond to threats.
Bird brains are built differently from mammal brains, yet they pack neurons densely, which may help explain their surprising intelligence.
Worth remembering
- Crows can recognise individual human faces.
- They remembered a threatening mask for years.
- Other crows learned to avoid the same mask.
In context
Crows belong to the corvid family, which also includes ravens, jays and magpies. Corvids have large brains for their body size, and some of their abilities rival those of great apes in experiments involving tools and planning.
New Caledonian crows shape sticks and leaves into hooks to fish insects out of wood. In laboratory tests, crows have solved puzzles requiring several steps in the right order, and ravens have shown they can save a tool for later use.
Living in cities brings crows into constant contact with people. Being able to tell a friendly person from a dangerous one helps them find food safely and avoid threats, which may explain why face recognition is so useful for them.
A closer look
Mobbing: safety in numbers
When crows spot a threat, such as a hawk, they gather and loudly scold it, a behaviour called mobbing.
Mobbing warns other crows and can drive predators away. The masked researchers experienced the same treatment.
Crow funerals
Crows often gather noisily around a dead crow. Researchers think this helps them learn about dangers in that place.
Experiments found crows avoided areas where they had seen a dead crow, especially if a person or predator was nearby.
Gifts from crows
There are well publicised stories of crows leaving small trinkets for people who feed them.
These reports are intriguing but anecdotal. Scientists find it plausible, though it has not been studied rigorously.
Related facts
More clever bird anatomy owls use their faces to hear.
Animals see the world differently honeybees have five eyes.
Another surprisingly clever animal octopuses have three hearts.
For more remarkable birds hummingbirds live only in the Americas.
Key terms
- Corvid
- A member of the crow family, including ravens, jays and magpies.
- Mobbing
- Group scolding and harassing of a threat by animals.
- Social learning
- Learning by watching or interacting with others.
Myth vs reality
Myth
Birds are simple animals with little memory.
Reality
Crows and their relatives solve problems, use tools and remember individual people for years.
People also ask
Can crows really recognise human faces?
Yes. Research in Seattle showed crows reacted strongly to a mask worn by people who had trapped them, while ignoring a neutral mask.
Do crows hold grudges?
In a sense. Crows kept scolding the dangerous mask for years, and other crows learned to do the same.
Do crows teach other crows?
The study suggests so. Crows that had never been trapped began scolding the mask, likely by watching other crows react.
Are crows intelligent?
Crows are among the most intelligent birds. They use tools, solve multi step puzzles and can plan for the future in experiments.
Can crows remember kind people too?
Many people report crows bringing them small objects, but positive recognition is less well studied than threat recognition.
