In this episode you'll hear about:

• The experiment that left researchers completely flabbergasted and rewrote what we thought we knew about animal intelligence

• Why flexibility, not raw smarts, is the real test of a thinking mind

• Whether the drive to use tools is something birds are born with, learn, or some surprising combination of both

• 00:04 - Behavioral Observations in Animals

• 02:16 - Exploring Avian Intelligence

• 07:04 - Bird Intelligence and Tool Use

• 17:09 - The Intelligence of Tool Use in New Caledonian Crows

• 21:57 - Evolutionary Adaptations of New Caledonian Crows

• 30:09 - Understanding Animal Intelligence: A Comparative Study

Timestamp Disclosure
These timestamps were generated using AI and may contain errors or omissions. They are provided for accessibility and reference purposes only and may not perfectly reflect the original audio.

Dr. Alex Kacelnik (Excerpt)

And we saw that and we were completely flabbergasted. This.

Dr. Scott Taylor

Yeah.

Dr. Alex Kacelnik

This kind of behavior is not. That didn't happen but hadn't been seen or documented in any other animal. Yeah, not even in chimps at that stage.

Dr. Scott Taylor

I have a drawer in my kitchen that I call the drawer. You know the one, it's got a flashlight that definitely doesn't work. A stupid amount of Allen keys from furniture I will never take apart.

Some batteries of unknown charge and a ton of okay, but bird stickers like the one you can find in our store. Shameless plug. But it's my chaos. And when I need something, I rummage through it and usually come out with something close to what I was looking for.

My toolbox, as it were. Now imagine you don't have hands or a drawer or a kitchen.

Imagine your entire survival depends on finding food hidden inside bark or wedged deep in a crevice. And the only thing you've got to work with is whatever you can find on the ground or snap off of a branch.

The first time I ever watched a bird solve that problem in real life with a tool, it stopped me in my tracks. I was on Santa Cruz island in the Galapagos, my very first trip to the mind blowing Galapagos islands.

At the time, I was hiking around Los the massive twin volcanic sinkholes surrounded by Scalicia forests and the highlands of Santa Cruz. If you haven't been. Scalicia forests are unlike anything else on Earth.

The trees are actually giant daisies, closely related to sunflowers that have grown into a full canopy. It feels ancient. They're covered in brown moss that collects fog from the air and quivers in the ocean breeze. The light filters through in this soft.

Green way and everything drips. It's quiet, except for the finches. And that's when I saw it. A woodpecker finch, a species of Darwin's finch, perched on a branch holding a. Cactus spine in its beak.

It was probing into a crack in the bark, angling the spine, adjusting, poking. And then it pulled out a larva. It ate the grub, repositioned the spine and went right back in.

I think it might be the only time I've ever watched a bird use a tool like that in the wild. And the thing that got me wasn't just the tool. It was the deliberateness, the patience. The bird was working. Which brings us to today's question.

Okay, but what's in a bird's toolbox to help us unpack? The science of avian tool use.

I'm talking with Dr. Alex Kiselnik, Emeritus professor at the University of Oxford, who has spent decades studying how New Caledonian crows think, innovate, and build tools that would impress an engineer. Because tool use in birds isn't just bird picks up stick. New Caledonian crows manufacture tools. They shape them. They choose materials.

In one famous experiment, a crow was left with only a piece of wire and did something remarkable. And when researchers flipped the script and changed the circumstances, the crow did something even more impressive.

So today we're going to dig into what tool use actually is and why it's so rare. We'll talk about what happens when a crow peels bark off a twig to thin it down or uses one tool to retrieve a second tool to get food.

We'll ask whether these birds are born with a drive to manipulate objects and why ranking animals on a single ladder of intelligence misses the point entirely. After the break, Dr. Alex Kiselnik helps us open the toolbox and look inside. Stay tuned. Okay, well, thanks for taking the time to join us on the podcast today, Alex. I really appreciate it.

Dr. Alex Kacelnik

It's a pleasure to be chatting to you.

Dr. Scott Taylor

This idea of bird intelligence.

So I think some people, when they think about, like, the intelligence of birds, maybe they think of an African grey parrot that can say a lot of different words.

But when you think of bird intelligence, what's the kind of simplest definition in your mind of what demonstrates intelligence and in birds, if there is one?

Dr. Alex Kacelnik

It's a good question because I should come clean and say from the beginning that I don't have a definition of intelligence. And to be honest, I think that most definitions that hang around are not particularly good.

People use the term intelligence without clearly knowing what is it that they mean. There are three sources of know how. One is what you have from your genes that biology provides.

The other is the things that you can learn from intelligence. And the rest is a spooky bit. When people or animals do things that we don't know how they do it.

In general, people tend to think that intelligence is the kind of things that are neither inherited nor. Nor learned. But that's not very satisfactory, if you see what I mean.

Dr. Scott Taylor

Yeah, yeah. I guess there's the famous quote, like, are we smart enough to know how smart animals are?

And it'd be great to get your take on that in the context of birds and unpack this a little bit more.

Dr. Alex Kacelnik

If you go.

Some decades ago, people thought that the behavior of birds was rigid and instinctive, while the behavior of mammals, and particularly humans, was completely flexible and not encoded by genes. In fact, this originates in the fact that it is true that birds are notorious for knowing a number of things without needing to learn from them.

But that doesn't mean that they can't also learn things and solve them creatively on the spot of the moment by reasoning in different ways.

So in fact, the greater richness of instinctual behaviors, which you have said, oh, how clever they are, they can do certain things without learning, and in addition, they can learn and solve problems. People thought that if you knew a lot of things by instinct, then that would decrease the amount of intelligence that you may actually show.

Dr. Scott Taylor

So, interesting.

Dr. Alex Kacelnik

I think it's fair to think of intelligence as the kind of things that you can solve flexibly.

If you can face different problems and if you only have one way to do it, and as soon as the thing, the problem changes one little bit, you can't solve it anymore, then that doesn't make sense to call it intelligent. But if you can accept all kind of transformations of the problems and still achieve your goals, then I would call that behavior intelligent.

Dr. Scott Taylor

Yeah, yeah, I think that's a really satisfying way to think about it. So then for you and in the bird world, or you can go more broadly if you want, but what are some of the best examples of that?

That flexibility, that kind of problem solving that you would infer to be intelligence versus just this is the thing I do and I can't be flexible.

Dr. Alex Kacelnik

I'm going to be slightly biased and tell you the examples with which I've.

Dr. Scott Taylor

Been involved, but yeah, that's why we invited you here.

Dr. Alex Kacelnik

We started about 25 or close to 30 years ago to connect with the research on New Caledonian crows.

But also some other researchers, colleagues, particularly one called Gavin Hunt and a few others, had been working for a few years on New Caledonian crows in the wild. And we connected to them and decided that we wanted to study in detail in the laboratory the conditions that led to tool use and the flexibility.

We brought them to the lab and did a few studies. We showed that they did use tools, that they could use them, they could select the right length of tools to retrieve some food, et cetera.

But there was something completely unexpected. One day we wanted to test if they picked a potential object to use as a tool, taking into account its functionality.

And so we gave a pair of New Caledonian crows two objects. One was a straight piece of wire pipe cleaner actually, and the other was a bent one.

And we put a vertical tube, the bottom of which there was a basket containing some food that they could see. But not reach. And we simply wanted to see if they would pick up the hook instead of the straight one, because that was useful to collect this.

And what happened was very interesting. The male, which was a little. Well, in general are a little larger and dominant, took the hooked wire away.

And the female was left with a piece of straight wire that she couldn't use to extract the basket, although she tried. And this is what happened, what surprised us.

Female picked a straight wire, went away from the site of a problem, basically some 30 centimeters away, to a tray which had a crack in the plastic and jumped the tip of the wire in this crack and pulled from the other side until forming a hook and then went back with a hook and extracted the basket from. From the tube. And my student, Alex Weir, who had only been working in the lab for six months at the beginning of his PhD, so that.

And fortunately he filmed it.

Dr. Scott Taylor

Very fortunate.

Dr. Alex Kacelnik

Yeah. And we saw that and we were completely flabbergasted. This. Yeah, this kind of behavior is not.

That didn't happen, but hadn't been seen or documented in any other animal, not even in chimps at that stage.

Dr. Scott Taylor

So at that stage, what year was that? That. That was documented then?

Dr. Alex Kacelnik

2002.

Dr. Scott Taylor

So that was the first time an animal was ever documented modifying a tool to then use the tool successfully, which is just incredible.

Dr. Alex Kacelnik

Yes, yes. Modifying it in that particular.

So sort of bending an artificial material, pliable material, to give it the right shape in the years after the hard work came. Because we said, well, maybe this is one of those things that animals know by genetic programming.

Maybe in the wild they bend some twigs and they are just rigidly reproducing that behavior.

So we said, well, there is one way to test their flexibility, and this was to put the food away from them at a distance and giving them a wire that was already bent so that it was too short to reach the full. And now if they were truly intelligent about it, they had to do the opposite. They had to straighten the wire in order to reach that.

And to our delight, when we did this, they also did the right thing, which was really fantastic.

Dr. Scott Taylor

That's amazing.

Dr. Alex Kacelnik

And then there's a whole cascade of things. So I can only construct by the argument by telling you more cases.

In one of them, for example, we gave them a situation where there was a tube with a small hole and they had to push a twig through the hole in order to push food to fall out of it through a vent and then they could consume it. And one of them picked up from the lab an unprepared twig and tried to put it in, but it turned out to be too thick.

And it was kind of pushing it for a while, unsuccessfully, and then took it away and started to peel the bark of the twig until one of the sides was thin enough and it worked on that side of the twig and then went to the other side, picked it from the thick, the remaining thick part, inserted the thin one and pushed it in. And that meant that it could modify a tool appropriately. Also, after seeing that it didn't work.

So if I carry on months later, we thought, well, what if you need a tool to reach another tool, which is the actual functional one? Can they detach themselves from the goal enough to take intermediate steps?

So we created a situation where food was very far and there was an available tweak that was enough to reach into another tube containing a tool.

But the tool they could reach was also too short and they could extract it and go to yet another tube when then there was a tool long enough to do the right thing. Again, to our delight, these animals solved that on first occasions.

So in order to make a scene that you consider the animal to have the flexibility to call their behavior intelligent, you could not stop at one observation. And also, it's not enough to see what they do in nature.

When you can't control the conditions in which it happens, you do experiments because you isolate the circumstances and you can actually tease apart what's going on. We wonder how much of these animals were pre programmed to do.

And so what we did using the fact that some of them bred in captivity, is that we took some of the chicks and raised them in a room or in rooms where there was no other adult animals and there were no sticks and no human ever held objects in front of them, but they were fed and otherwise kept with all the other circumstances, all the other freedom in a rich environment. And one day we put sticks in the room and they were pretty young, about two months old at the time that we first started to see this.

And what they did is picking up sticks and start to operate on these sticks in ways that were useless because there was no food available. But they were holding them and making some of the movements that they do when extracting food.

And that proved, I should say, that other species of birds don't do this.

That proved that in addition to being flexible and capable of solving different configurations of problems, they are also supplied by their genetic inheritance with abilities or tendencies to try that basically, it proves once again, as if it needed proof, that all animals Ability to solve problems are a mosaic of inherited traits and learned abilities and the capability to operate with those two, to make computations, to actually create novel solutions to novel problems.

Dr. Scott Taylor

It sounds like every time you gave them a new challenge, they solved it. Which was both satisfying, but I'm also like, it must have been just so exciting to see how good at problem solving these birds were.

Dr. Alex Kacelnik

It was exciting, and it continues to be. Another people continues to do work which discovering new abilities.

But it's also instructive to us to see what kind of errors they commit, what kind of things they say an adult human being would not do. And they do, because that tells us a little bit how they think, how it is to be a crow, as it were. I can give you one example.

One bird called Wassell was given a task in which the ground was agreed the roof of a box constructed with chicken wire. And it had a hole in the middle, a well about, I would say, about 15 centimeters deep with a basket in the bottom.

And we provided a hook tool to examine how well the animal would actually adjust the motricity of getting there. We knew that they already. We already knew that they use hooks. So we gave it a hook to try to see how it did it.

And this animal picked the hook and put it down the well and tried a few things. It failed at the beginning and eventually could engage the basket, take it up, consume the bait, and then started to look inside.

And the basket was empty. And it hesitated for a bit. And then you know what it did?

It picked up the hook and put the basket back down the well and then picked it up again and look at its content.

Dr. Scott Taylor

That's amazing.

Dr. Alex Kacelnik

So in a sense, you could say that's not very clever because the basket is empty. But then you think, how could the animal know? Maybe that's the way it gets filled, the way we actually get water from a well by lowering a bucket.

And he did these two or three times, and when it didn't work, it went away, it dropped it.

So an error like this tells you it's not an error, but, I mean, an unsuccessful behavior like this tells you that they are constantly exploring their environment and learning new features that they can incorporate in their repertoire.

In research, there's a whole field called comparative cognition, where very often people study adult animals to show they have this ability or that ability.

But the truth is, unless you examine how the animals are acquire these abilities, you are learning a very limited amount about what it means to be an animal of that nature, or how is it that they Learn.

Dr. Scott Taylor

Yeah, that's super interesting to think about. In the context like, so New Caledonian.

Crows are really this poster child for tool use and modification and all of these things, especially like across animals, not just in the bird world. There are other corvids that do use tools. There are other kinds of birds that use tools.

What do you think it is about kind of the evolutionary history of the New Caledonian crow that has led to this combination of traits that you've been studying? I mean, they're an island population, but what more than that?

Dr. Alex Kacelnik

Yeah, well, you could be hitting on the critical thing, but of course there are other island populations of birds that didn't acquire tool use. So there were other circumstances and we can't reproduce them, really.

For example, there's an island in which there are no woodpeckers and there's rotten wood in trees which contains insects and insect larvae. So there is. That only tells you that there was an opportunity, there was kind of food waiting to be exploited and very few competitors.

So that's one thing we, we also know that even morphologically, the New Caledonian crows seem to have evolved some properties like the shape of their beak, which actually is well designed to accommodate their use of tool.

So they, they really is straight, is straighter than other corvids, which tend to have a curvature and that allows them to pick up a stick and look at them in having it forward so that they can actually poke directly. So they obviously are adapted both psychologically and anatomically. In terms of evolutionary history.

We can explain an elephant, but we can't predict an elephant. Nobody could tell how the ancestors would evolve to end up in the animal we see today.

But when you see them, you can say, oh, these selective pressures led to there was this competition or there wasn't, and there was this fauna around and the food opportunities and other characteristics of this kind. Relatively hard to get food. That means that you have to be imaginative to do it.

I think the most interesting thing about biology and science in general is to admit our ignorance of very fundamental problems because that's the reason to keep. That's the reason to keep working.

So, yeah, I don't think anybody can tell what was special, unique about this species that led to this extraordinary adaptation.

Now, as you said, other corvids have the general intelligence that allows them to start using tools in similar circumstances, but none, to my knowledge, has displayed the level of flexibility and intensity of tool use in everyday life as this particular species. So, yeah, I cannot offer an answer to that.

And I hope that my colleagues that younger colleagues that will continue to work on these fascinating animals will actually uncover more and more information. Still, it's a difficult area.

Dr. Scott Taylor

It is, for sure.

Yeah. Like, if you think about other corvids, I mean, it'd be great. I think so.

Rooks have been shown to use tools, but not in the wild, only in captivity, I think. I'm pretty sure the Hawaiian crow, which is unfortunately extinct in the wild, more or less.

They're trying to reintroduce them, but avian malaria is causing a problem as well as the native. I think hawks kill them, but I think there's evidence of Hawaiian crows using tools. I don't know. I think that's got to just be in captivity.

Dr. Alex Kacelnik

Almost certainly. If they use it intensely in captivity, I can see no reason why they wouldn't do it in the wild.

Dr. Scott Taylor

Yeah, exactly.

Dr. Alex Kacelnik

It is, as you say, a fascinating case in which we have another case.

And in the case of the Hawaiian crow, researchers have found that they have the horse living species accessible because they are all captive and they can study the incidence of tool use across all of them.

What is necessary is to follow the discovery and report of disability with an intense research program that controls the history of individual animals and offers them the sort of variation in. In challenges that leads to have a complete picture of the animal's cognitive ability. So it's not.

It's not enough to show, yes, they can use tools by now. This was good 20 years ago. Now we know that many do. So we need to go deeper into that.

Dr. Scott Taylor

Definitely.

And it's interesting to think about, like in the Hawaiian crow, with their population being reduced to so few individuals that even if there was widespread tool use in the original wild population, what has that population decline and necessarily inbreeding done to all of these factors that influence flexibility and intelligence in that sense of modifying tools and using them. But it's a sad case where, I guess, yeah, it's harder to study because. There are so few of those individuals. But New Caledonian crows,. Are they still quite common in the wild or are. They facing challenges there?

Dr. Alex Kacelnik

Okay. No, they are very common. Of course, they are limited to one island and the smaller islets around it, but they are not endangered within the island.

Dr. Scott Taylor

Can you talk to us a little bit about the comparative work that you've.

Done between Kea and the New Caledonian crows? Because parrots are that kind of other group of birds that we think of as problem solvers.

Or if you go on vacation in New Zealand, you have to be careful, they'll steal your keys and Those sorts of things, mischievous, like many parrots are.

Dr. Alex Kacelnik

Indeed. Indeed. One particular study, one informative study, we offered this animal animals four different ways to get at a food. A bait.

It was a box with multiple openings, and from each side you could obtain food by doing a particular manipulation. In one case, there was a food tied to a string and you simply had to pull to get it out.

That one was so easy that all our animals did it within seconds and offered no interesting comparison.

The other one was shoot a hole where you could push a little like a marble, a little ball that you could put in that hole, and it dropped a chute and displaced platform. And then food was delivered and they could eat it again.

Both species did it, but the New Caledonian crows were more handy in actually picking the ball than the kias that have an extremely curved beak. Yeah, yeah.

Then we gave them a door which had a little hook of a handle that they had to simply pick up the hook, open the door and put their heads through to do it. Now, the kias did it immediately. The New Caledonian crows had some trouble to do it.

And then the fourth case was using a stick to push food that was on top of a platform and so that the food would simply fall out. Now, the New Caledonian closed this immediately and the kias took quite some time.

But this was time that was caused by what is called an ergonomic difficulty, difficulty in manipulating the stick and putting it forward because the shape of that beak didn't allow it. So what was our conclusion of this kind of comparison? Conclusion was that overall, the two species were capable of flexible behavior.

Keas overall showed out of this limited set of tasks a margin of greater flexibility and innovativeness that the New Caledonian crows. But we don't make. This was in.

In this limited context, and it shouldn't be read as meaning that one species is more intelligent than the others, because you would need to have a. There is no ranking. They have different abilities. You know, you may be very good for playing piano and I may be very good for playing chess and.

Yeah, and then that. How could you tell who is more intelligent? Is a matter of preference.

So different species have minds evolved to solve the typical problems they face in nature.

And in this case, these two species excel in that and in a big repertoire of different species, different tasks, but we can't put them reliably, and it doesn't make sense to put them reliably one above the other.

Dr. Scott Taylor

Totally. We've reached the part of the show. That we call that's BS or that's bird stuff where we give our guests. An opportunity to debunk a myth that ruffles their feathers.

So, Alex, what do you want to.

Dr. Alex Kacelnik

Call BS on I would give a very heartfelt advice to most of our listeners, and this is that whenever they want to insult someone very, very deeply, next time they have a conflict, they don't call it bird brain. I think that would be a very inappropriate insult.

Dr. Scott Taylor

I love that. Amazing. Awesome.

Well, thanks so much for taking the time to join us. I've really enjoyed hearing more about your research and these amazing New Caledonian crows. So thanks for taking the time.

Dr. Alex Kacelnik

It's been a pleasure.

Dr. Scott Taylor

Birds are dinosaurs, and around here we like our snacks. So we end each episode with a dinosaur nugget. Today's nugget. Out of roughly 11,000 bird species, only a handful regularly use tools.

But what Alex showed us is that the interesting question isn't whether a bird can use a tool. It's whether it can adapt when the problem changes. Can it bend a wire into a hook? Straighten one when the situation demands it?

Use one tool to retrieve a second tool to reach food? New Caledonian crows do all of that.

And when researchers raised crow chicks in total isolation, no adults, no sticks, no demonstrations, those chicks still picked up objects and started manipulating them at just two months old.

For New Caledonian crows, at least, there's an innate drive to interact with objects as tools, and flexibility builds on top of that, as Alex reminded us, this isn't an Olympic ranking. It's about understanding how minds work, including the ones inside a brain the size of a walnut. That's a wrap on this week's episode.

Ok, but what's in a bird's toolbox? If you're an Apple listener, good news. You'll be able to toggle on the video version of the podcast beginning later this spring.

Thanks for supporting our show. We'll catch you next time. Byeeee. Okay, But... Birds is hosted by Scott. Taylor, with production and creative by Zach Karl.

Transcript Disclosure
This transcript was generated using AI-assisted transcription and may contain errors or omissions. Please refer to the audio or video episode for the most accurate representation.

All audio, video, and images in this episode are either original to Okay, But... Birds (© Okay Media, LLC) or used under license/permission from the respective rights holders. Bird media from the Macaulay Library is used courtesy of the Cornell Lab of Ornithology as follows:

• Woodpecker Finch audio contributed by Robert Bowman, ML82522

• New Caledonian Crow audio contributed by Lucas DeCicco, ML188764

• Hawaiian Crow audio contributed by Tim Burr, ML218670

• Hawaiian Crow video contributed by Timothy Barksdale, ML425081

• Kea audio contributed by William V. Ward, ML8523