Bird IQ Tests: 8 Ways Researchers Test Bird Intelligence - National Audubon Society

Wren: Welcome to Bird Brains — the show where "bird brain" is absolutely, one hundred percent a compliment. I'm Wren, ornithologist, corvid obsessive, and your guide to the surprisingly rich inner lives of crows, ravens, magpies, and jays. Today we've got stories that will make you stop and stare the next time a crow looks you dead in the eye on your morning walk — because trust me, it is absolutely judging you. A huge thank you to our sponsors: Ada, who helps clients integrate A I into their workflows; Ago Consulting — that's "Ahh-Go" — silicon development consulting from A I to SoC; and Zen Semiconductor, an umbrella company with a portfolio across the silicon industry. Okay, friends. Let's get into it. Wren: So, thread one. Corvid cleverness. And I want to start with a question that sounds simple but is actually kind of philosophically wild: how do you even test how smart a bird is? Because you can't exactly hand a crow a standardized test and tell it to bubble in the right answer with a number two pencil. Researchers have had to get genuinely creative — and in doing so, they've revealed things about corvid minds that nobody expected. Wren: The National Audubon Society recently pulled together eight of the ways scientists actually probe bird intelligence in the field and in the lab, and honestly, reading through them feels like watching someone design an escape room specifically for a crow. Which, honestly, is not far off. Wren: One classic method is the Aesop's Fable task. Yes, named after the actual fable — the one where the crow drops stones into a pitcher to raise the water level and reach the food floating on top. Researchers set up exactly that scenario: a tube of water, a treat floating just out of reach, and a pile of objects nearby. And corvids — crows, rooks, ravens — they figure it out. They select stones over lighter objects. They choose solid objects over hollow ones. They understand, on some level, that what they drop in matters. Wren: Now here's what makes that genuinely startling. It's not just trial and error. Studies have shown that corvids will choose the right object on the first try, or after very few attempts — which suggests something closer to insight than random poking around. Insight. That word matters. It implies a mental model of cause and effect, a kind of "if I do this, then that happens" reasoning that we used to think was uniquely human, or at least uniquely primate. Wren: And then there's the multi-step tool use. New Caledonian crows are probably the rockstars of this category. There's a famous experiment where a crow named Betty — this is a real crow, studied at Oxford — spontaneously bent a straight wire into a hook to fish food out of a tube. She hadn't been trained to do it. She just... did it. And when researchers removed the hooked tool and gave her only straight wire, she bent it again. The improvisation is what gets me. That's not instinct. That's problem-solving in real time. Wren: Science Friday recently explored what puzzle-solving crows can teach us about animal intelligence more broadly, and the answer, it turns out, is a lot. Because when we study corvid cognition, we keep bumping into this uncomfortable realization: the things we thought made human intelligence special — planning, tool use, understanding other minds — corvids are doing versions of all of it. With brains the size of a walnut. Which is either humbling or thrilling, depending on your perspective. I personally find it thrilling. Obviously. Wren: What puzzle research also reveals is that corvids are flexible. They don't just learn one solution and apply it robotically. They adapt. If a method stops working, they try something else. That behavioral flexibility is a hallmark of what cognitive scientists call "general intelligence" — and it's rare in the animal kingdom. Corvids have it in spades. Wren: Alright, thread two. How their minds actually work. Because tool use is impressive, sure, but I want to pull back the lens a little and talk about what's happening underneath — in the corvid brain itself — because the story there is one of the most fascinating in all of neuroscience, full stop. Wren: For a long time, the prevailing assumption was that bird brains were, well, primitive. Birds don't have a neocortex — that's the layered outer structure of the mammalian brain that we associate with higher-order thinking. And for decades, the absence of a neocortex was taken as evidence that birds couldn't be doing anything particularly sophisticated upstairs. That assumption has been thoroughly, gloriously dismantled. Wren: It turns out that the region of the bird brain called the nidopallium caudolaterale — and yes, I love saying that — functions analogously to the mammalian prefrontal cortex. That's the region associated with planning, decision-making, and flexible behavior. Birds evolved a completely different brain architecture to get to a similar cognitive destination. Evolution, it seems, found more than one road to smart. Wren: And the density of neurons in corvid forebrains is remarkable. A 2020 study published in PNAS found that the brains of corvids and parrots contain far more neurons per unit of brain mass than most mammals — including some primates. So when people say "bird brain" as an insult, I always want to say: yes, actually. A very neuron-dense, highly efficient bird brain. Thank you for the compliment. Wren: Now let's talk about caching, because this is where corvid memory absolutely shines. Western scrub jays — now called California scrub jays — have been the subject of some of the most elegant memory experiments in animal cognition. These birds cache thousands of food items. Thousands. And they remember not just where each item is hidden, but what it is, and crucially, when they hid it. Wren: That last part matters enormously. Perishable foods — like worms — go bad faster than non-perishable ones, like nuts. And jays, when given enough time before retrieval, will preferentially go back to the nut cache rather than the worm cache — because they seem to know the worms have spoiled. They're tracking time. They're thinking about the future state of their food. Researchers call this episodic-like memory — a mental time travel of sorts — and it was thought to be uniquely human until corvids showed up and said, hold my acorn. Wren: There's also the social dimension of corvid cognition, which I find endlessly fascinating. Jays don't just remember where they cached food — they remember who was watching when they hid it. If another jay was present during caching, the cacher will often return later and move the food to a new location. They're modeling another bird's knowledge. They're thinking, that bird saw where I hid it, so I need to rehide it. That's called theory of mind — understanding that others have beliefs and intentions distinct from your own. It's a big deal. Wren: And face recognition. Oh, this one is personal for crows. Studies by John Marzluff and his team at the University of Washington showed that American crows not only recognize individual human faces — they hold grudges against people who have wronged them. Researchers wearing specific masks while handling crows found that those crows would scold, dive-bomb, and alarm call at anyone wearing that mask, even years later, even when the mask was worn by a completely different person. They also recruited other crows to join in the mobbing. They spread the grudge socially. If that doesn't impress you, I don't know what will. Wren: Thread three. Corvids and people. Because all of this intelligence doesn't exist in a vacuum — it plays out in the messy, complicated, deeply interesting space where wild corvids and humans share the same world. Wren: I want to start with Jasper. Jasper, Alberta — the mountain town in Canada — and a beautiful piece of local journalism that recently explored what the people there experience living alongside corvids every single day. And what comes through in these accounts is something I hear again and again from communities that pay attention to the corvids around them: these birds are watching us just as much as we're watching them. Wren: In places like Jasper, ravens in particular have become deeply embedded in the human landscape. They've learned the rhythms of the town — when the garbage goes out, when the tourists arrive, when the ski lifts start running. They exploit human routines with an almost unsettling precision. But there's also something warmer happening in some of these accounts. People who feed corvids regularly, who spend time outdoors in the same spots, start to notice that individual birds recognize them. The dynamic shifts. It stops being bird and human and starts feeling more like — neighbors. Wren: The most famous documented case of corvid gift-giving is probably Gabi Mann, the young girl in Seattle who began leaving food for the crows in her neighborhood as a child. Over time, the crows began leaving things for her in return — buttons, a small piece of metal stamped with the word "best," a tiny light-up ball, a corroded screw. These weren't random objects. They were consistently left after Gabi provided food, suggesting some form of reciprocal exchange. Gabi's mother kept meticulous records. The story was covered by the BBC. It's real. Wren: Now, scientists are careful — and rightly so — about what we conclude from gift-giving behavior. It might not be intentional generosity in the way we'd experience it. It might be a byproduct of caching behavior near a reliable food source. But what's not in dispute is that the crows were engaging consistently and specifically with Gabi as an individual. They knew her. They interacted with her differently than with strangers. And that specificity — that recognition and differentiated response — is itself remarkable. Wren: There are also documented cases of ravens forming long-term bonds with individual humans — particularly in places like wildlife rehabilitation centers and research facilities where ravens are raised from young. These aren't domesticated animals. They're wild birds who have chosen, in some meaningful sense, to invest in a particular relationship. Ravens in the wild form long-term pair bonds with other ravens that can last for years. The cognitive and emotional architecture for attachment is clearly there. Wren: And then there's the urban angle, which I find fascinating from an evolutionary standpoint. Cities have become, in the last century, a kind of pressure-cooker for corvid intelligence. Urban crows and ravens face novel problems constantly — traffic, novel food sources, human schedules, other species, new physical environments. And what researchers find is that urban corvids tend to be bolder, more innovative, and faster problem-solvers than their rural counterparts. The city is, in effect, selecting for smarter birds. We are, inadvertently, running an intelligence experiment on corvids at the scale of entire metropolitan areas. Wren: One beautiful example of this is the crow that figured out how to use traffic to crack nuts. Carrion crows in Japan began dropping hard-shelled walnuts in front of cars to crack them open — a behavior that's been observed and filmed. But here's the refinement that got researchers really excited: the crows learned to drop nuts at crosswalks, then wait for the light to change, walk out into the road alongside pedestrians to collect the nut, and then return to the sidewalk. They were using traffic signals. They were timing their behavior to the pedestrian crossing. That level of behavioral sophistication, in a wild urban bird, is extraordinary. Wren: So what do we take from all of this? From the stone-dropping and wire-bending, from the episodic memory and the cache re-hiding, from the face recognition and the grudge-holding, from the gift-giving and the traffic-signal-reading? I think we take a lesson about where intelligence lives — and where we've been looking for it. Wren: We've spent a long time looking for minds like ours, in animals that look like us. And corvids are the universe's way of tapping us on the shoulder and saying — hey, you might want to widen that search. Intelligence is not one thing. It is not housed in one kind of brain or one kind of body. It emerges wherever the pressures of survival demand it, and it takes shapes we didn't predict and couldn't have imagined. And that, to me, is one of the most beautiful facts in all of science. Wren: Bird Brains is brought to you by Ada, Ago Consulting, and Zen Semiconductor — and I am genuinely grateful for their support in keeping this show flying. If today's episode made you see crows differently, please share it with someone who needs their mind blown. Subscribe wherever you get your podcasts, and check the link in show notes for sources, further reading, and all the wonderful research I pulled from today. Until next time — stay curious, keep looking up, and remember: bird brain is a compliment. The highest one I know.