Are Crows Really That Smart?

Yes, crows really are that smart. Crows and their relatives, the roughly 130 species of corvids, make and modify tools, recognize individual human faces for years, plan for future needs, remember thousands of hidden food items and learn from each other. On several standard tests of reasoning and planning, the best-studied corvids perform about as well as chimpanzees and other great apes.

“Bird brain” was once an insult. Corvid research over the past few decades has turned it into something close to a compliment. This guide explains what the evidence shows, how a small bird brain manages such feats, where popular stories go beyond the science, and what crow intelligence means for anyone who feeds birds.

Quick answer: what makes crows smart

• Tool use and tool making. New Caledonian crows shape hooks from twigs and cut tools from leaves in the wild.
• Face recognition and grudges. American Crows remember people who threatened them and teach other crows to scold them.
• Planning. Ravens and scrub-jays in experiments prepare for future events, not just immediate rewards.
• Memory. Food-caching corvids store thousands of items and remember where they are, what they are and roughly when they hid them.
• Social learning. Crows learn about danger, food and people by watching each other.
• Dense brains. Corvid forebrains pack in neurons at very high density.

Which birds count as crows?

The crow family, Corvidae, includes about 130 species worldwide. It covers:

• Crows and ravens, such as the American Crow, Fish Crow, Common Raven, Carrion Crow, Hooded Crow, House Crow and Australian Raven.
• Rooks and jackdaws, common across Europe and Asia.
• Jays, including the Blue Jay, Steller’s Jay, California Scrub-Jay and Eurasian Jay.
• Magpies, including the Black-billed Magpie in the American West and the Eurasian Magpie.
• Nutcrackers, such as Clark’s Nutcracker in western mountains.

If you have jays at your feeder, you are already hosting a corvid. Our guide to attracting Blue Jays covers their feeding habits.

What can crows do that shows real intelligence?

Can crows make tools?

The standout toolmaker is the New Caledonian crow, native to the islands of New Caledonia in the South Pacific. In the wild, these crows:

• Strip and shape twigs into hooked tools to pull insect larvae out of dead wood.
• Cut stepped, tapered tools from the barbed edges of pandanus leaves.
• Keep and carry favored tools and reuse them.

In a 2002 study in Science, Alex Weir, Jackie Chappell and Alex Kacelnik at Oxford reported that a captive New Caledonian crow named Betty bent a straight piece of wire into a hook to lift a small bucket of food from a tube. That became one of the most famous moments in animal cognition research. Later work in the wild showed that hook bending is part of the species’ natural repertoire with plant stems, so the result may reflect a flexible use of a natural skill rather than pure invention. It is still remarkable.

Other studies have shown New Caledonian crows using one tool to get another, known as metatool use, and in a 2018 study, assembling compound tools from separate pieces to reach food that no single piece could reach.

The Hawaiian Crow, or ‘Alala, which survives only through captive breeding and reintroduction efforts, was shown in 2016 to use sticks to extract food as well. Most other corvids are not habitual tool users in the wild, but many solve tool problems in captivity.

Can crows solve puzzles like Aesop’s fable?

In Aesop’s fable, a thirsty crow drops pebbles into a pitcher to raise the water level. In 2009, Christopher Bird and Nathan Emery of the University of Cambridge tested this with Rooks, which do not use tools in the wild. The rooks dropped stones into a tube of water to raise a floating worm within reach, and they chose larger stones over smaller ones. Later studies found New Caledonian crows and Eurasian Jays could also solve versions of this task, though with some limits in understanding exactly which objects would work.

Do crows really remember human faces?

Yes, and this is one of the best-documented findings. Starting in the mid-2000s, John Marzluff and colleagues at the University of Washington trapped and banded American Crows on campus while wearing a particular “dangerous” mask. Later, people walking through campus in the same mask were scolded and mobbed by crows. A different, neutral mask drew little reaction.

Key points from the research:

• The memory lasted years. Crows continued to scold the dangerous mask for many years after the original trapping.
• Crows that were never trapped joined in. The number of scolding crows grew over time, suggesting young and unexposed crows learned from others.
• It is about the face. The masks controlled for clothing, gait and other cues, so the crows responded to facial features.

Brain imaging studies by the same group found that seeing the dangerous face activated brain regions associated with fear and learning in crows. If you have ever wondered whether backyard birds know you, our article do birds recognize the people who feed them covers the evidence across species.

Can crows plan for the future?

Planning, meaning acting now for a need that will arise later, was long thought to be uniquely human. Corvid studies challenged that.

• Scrub-jays and caching. Nicola Clayton and colleagues at Cambridge showed that Western Scrub-Jays (the group now split into California and Woodhouse’s Scrub-Jays) remember what they cached, where, and roughly how long ago, an ability described as “episodic-like memory.” In a 2001 study in Nature, jays that had themselves stolen from others were more likely to move their caches to new sites if another jay had watched them hide food.
• Ravens and future tools. In a 2017 study in Science, Can Kabadayi and Mathias Osvath of Lund University found that ravens selected a tool they would need later to open a puzzle box, and saved a token to trade for a reward the next day, performing comparably to great apes on similar tests.

Can crows count?

Several studies suggest crows have strong numerical abilities. Research led by Andreas Nieder at the University of Tübingen, working with Carrion Crows, has found neurons in the crow forebrain that respond to specific numbers of items, and in a 2024 study the team reported that crows could be trained to produce a specified number of calls, from one to four, in response to cues. These are laboratory results, so they show what crows can learn, not necessarily what they do in the wild.

Do crows hold “funerals”?

American Crows often gather and call loudly around a dead crow. Research by Kaeli Swift and John Marzluff, published in 2015, found that crows exposed to a dead crow, especially with a person nearby, later scolded that person and were more cautious about the location. The researchers interpreted this as learning about danger rather than grief. The word “funeral” is catchy but misleading. For the wider question of emotion, see our article do birds grieve.

Do crows play?

Many corvids appear to play, including sliding down snowy roofs, dropping and catching objects in flight, and teasing other animals. Play is hard to study rigorously, but it is often associated with intelligent, long-lived animals. Our guide do birds play looks at the evidence.

Do crows know each other as individuals?

Evidence suggests they do. Corvids live in societies where it pays to know who is who: family members, mates, neighbors and rivals. Studies of Common Ravens in Austria found that ravens responded differently to recorded calls of former group mates than to unfamiliar ravens, even after years apart, and adjusted their responses to calls that did not fit the expected rank order. Pair-bonded corvids, such as Rooks and Jackdaws, support their partners during conflicts and appear to track the relationships of others.

This social knowledge links to a larger idea called the social intelligence hypothesis: animals living in complex, shifting groups need powerful brains to keep track of allies and competitors. Corvids fit that pattern, as do primates, dolphins and parrots.

Can crows understand what other crows know?

This is harder to test, and researchers disagree on how to interpret results. The scrub-jay re-caching studies suggest jays take into account whether another bird saw them hide food. Experiments with ravens found they guarded caches more when they could hear a competitor behind a screen with a peephole open, which some researchers interpret as a basic understanding of what others can see. Whether this amounts to “theory of mind” in the human sense is still debated. It is safest to say corvids are sensitive to what others can see and know, without claiming they reason about minds the way adults do.

Are parrots smarter than crows?

They are close rivals. Parrots, such as African Grey Parrots and the Kea of New Zealand, show many of the same abilities: problem solving, tool use in some species, vocal learning and long memories. Both groups have densely packed forebrain neurons. Which is “smarter” depends on the task, and the two groups are best seen as separate evolutionary experiments in bird intelligence that reached similar results.

How can a small bird brain be so smart?

Do crows have large brains?

Relative to body size, corvid brains are large, comparable to some primates. But size alone does not explain it. A crow’s brain weighs only a small fraction of a chimpanzee’s.

Do bird brains have more neurons than we thought?

Yes. A 2016 study in PNAS led by Seweryn Olkowicz and Suzana Herculano-Houzel counted neurons in the brains of many bird species. It found that songbird and parrot brains pack neurons much more densely than mammalian brains. Large-brained corvids and parrots had numbers of forebrain neurons comparable to those of some monkeys, despite far smaller brains. More neurons in a small space also means shorter distances between them, which may speed up processing.

Do birds have something like a cortex?

The bird forebrain looks very different from the layered mammalian cortex, which is one reason scientists long underestimated it. Research over the past two decades has shown that parts of the bird pallium are functionally similar to the mammalian cortex. In particular, a region called the nidopallium caudolaterale appears to play a role similar to the mammalian prefrontal cortex, involved in decision-making, working memory and flexible behavior. Crows and primates reached similar cognitive abilities with differently organized brains, an example of convergent evolution.

Why did crows evolve to be so smart?

Researchers have proposed several reasons, and they probably work together.

1. Varied diets. Corvids are generalists, eating seeds, fruit, insects, eggs, carrion and human food. Exploiting so many foods rewards flexible problem-solving.
2. Caching. Hiding and retrieving food requires memory, and protecting caches from thieves may favor understanding what others know.
3. Complex social lives. Many corvids live in families or groups, form long-term pair bonds and remember relationships. American Crows often breed cooperatively, with older offspring helping raise younger siblings.
4. Long lives and slow development. Corvids live many years and spend a long time as juveniles, which gives time to learn.

How do scientists test whether a bird is smart?

Headlines about clever crows often skip the method, so it helps to know what makes a result convincing.

1. Controls for simple explanations. A good experiment rules out trial-and-error learning, lucky guesses and cues from the experimenter.
2. Transfer to new problems. A bird that solves a novel version of a task, without training on it, shows more flexible understanding than one that learned a single trick.
3. Sample size and replication. Many cognition studies test only a handful of birds. Results are stronger when other labs repeat them.
4. Wild versus captive behavior. Lab tests show what a species can learn. Field studies show what it actually does.

By these standards, crow face recognition, New Caledonian crow tool making and scrub-jay caching are well supported. Some other claims, such as mirror self-recognition, still need more replication.

Myths vs facts about crow intelligence

What does crow intelligence mean for backyard birders?

Will crows learn my routine?

Very likely. Crows quickly learn when and where food appears. If you feed at the same time each day, expect crows to wait for you. If you want to discourage them, vary timing and use feeders that exclude large birds. Our guide on keeping starlings and grackles off feeders covers feeder designs that also limit crows.

What should I feed crows, if anything?

Unshelled peanuts and suet appeal to crows and jays. Avoid bread and salty or processed human foods; our guide to what not to feed birds explains why. Corvids cache food, so they may carry off more than they eat, a behavior explained in why do birds hoard food.

Are crows a threat to smaller birds?

Crows and jays eat eggs and nestlings of other birds, which is a natural part of their diet. Research generally finds that corvid predation is not the main driver of songbird declines, which are linked more strongly to habitat loss, cats and collisions. Still, dense shrubs and well-designed nest boxes help protect small birds.

Is it okay to interact with crows?

Watch them, learn their calls and enjoy them. Crows and other native birds are protected under the Migratory Bird Treaty Act in the United States, which limits harming or capturing them. Avoid trying to tame wild crows, which can lead to conflicts with neighbors.

Quick facts

• The crow family includes about 130 species of crows, ravens, jays, magpies and nutcrackers.
• New Caledonian crows make hooked and leaf tools in the wild.
• American Crows remember threatening human faces for years and teach others.
• Ravens in experiments planned tool use and bartering for the next day.
• Scrub-jays remember what, where and roughly when they hid food.
• Corvid and parrot forebrains hold neuron numbers comparable to some monkeys.
• Crow “funerals” appear to be about learning danger, not grieving.
• Crows are protected by law in the US, with limited exceptions.

Sources

• Weir, A. A. S., Chappell, J. and Kacelnik, A. (2002). Shaping of hooks in New Caledonian crows. Science
• Marzluff, J. M. et al. (2010). Lasting recognition of threatening people by wild American crows. Animal Behaviour
• Olkowicz, S. et al. (2016). Birds have primate-like numbers of neurons in the forebrain. PNAS
• Kabadayi, C. and Osvath, M. (2017). Ravens parallel great apes in flexible planning for tool-use and bartering. Science
• Bird, C. D. and Emery, N. J. (2009). Rooks use stones to raise the water level to reach a floating worm. Current Biology
• Cornell Lab of Ornithology, All About Birds: American Crow