E46: Okay, but why are we obsessed with crows and ravens?

Scott Taylor: A murder. An unkindness. A scold. The names for groups of these birds are not friendly. Still, these are the birds many of you tell us you want to befriend. More on why that's a bad idea later. Many of you have also been asking for a crow episode. Corvids include crows, ravens, jays, and magpies. There are about 130 species and they live on every continent except Antarctica. They're social and they're smart. Their brains are bigger than you'd expect for their body size. That's episode 28. And a few species even make and use tools. That's episode 18. People may have told more stories about crows and ravens than about any other bird. In Aboriginal Australia, Crow, or Waang, is an ancestral trickster, often set against Eagle, Bunjil. On North America's Northwest Coast, Raven steals the sun, sets it in the sky, and coaxes the first people out of a clamshell. Odin, in Norse myth, has two ravens. Some oral histories may even preserve real events from thousands of years ago, like rising seas in Australia and the eruption of Mount Mazama in Oregon. So it's tempting to call the crow and raven stories the oldest of all, but none of them can be dated. The best we can say is that these watchful birds have been in our stories for as long as we've been telling them. They're probably in a few of yours.

Scott Taylor: Which brings us to the topic of today's episode: Okay, but why are we obsessed with crows and ravens? To help us unpack that, I'm joined by Dr. Claudia Wascher, professor of behavioral biology at Anglia Ruskin University. After the break, Claudia walks us through what makes corvids seem so clever and when clever might be something simpler. We get into their friendships, their fights, and how they decide who's worth listening to. And we meet a crow named Hugo who left a lasting mark on his flock. Stay tuned.

Scott Taylor: Welcome back to the podcast, everyone. I'm really excited to have Claudia here today to talk about crows and ravens and I guess corvids in general. So thanks for joining us, Claudia.

Claudia Wascher: Thanks for having me.

Scott Taylor: Of course, I thought we could just start off with this reputation that these birds have. So crows and ravens, when I think of a clever bird, I often picture one of them. What do they do that earns them this reputation for being clever?

Claudia Wascher: And where to even start about this? There are so many things. So in general, corvids have all sorts of cognitive adaptations, which help them to solve problems in their ecological environment, but also in their social environment. So that's why we think corvids are generally so clever. I think something to highlight is that they are pretty flexible in their behavior, so they can adapt to new problems immediately. They can solve novel problems, which is sometimes something which we don't see in other species. Where if individuals are faced with a totally new problem, which they have never seen before, they probably give up or get really frustrated versus corvids. It almost looks a bit like they love the challenge and they would play around and manipulate things until they kind of solve the problem. There are two species of corvids, which we might talk a bit more about later anyway, which are tool users. So those two species are able to use tools in everyday life. They also make these tools. I know, and I will point towards, you have already done an episode on this with Alex Kacelnik, which I've listened to, and I would recommend it to all your listeners because it's an absolutely brilliant episode. I enjoyed that a lot. But tool use in animals is very rare. If you think about it, you can probably come up with a handful of species who do it. So that's something which we in biology think there must be something special about it if only so few species do it. And yeah, so the New Caledonian crow and the Hawaiian crow, which quite interestingly is extinct in the wild. That's also something which kind of shows that it's incredibly important to study the couple of animals. There are about 100 individuals left in captivity and they are at the moment heavily studied for tool use.

Scott Taylor: Yeah. And it's so cool to me that those two tool users are island dwellers. Like, you know, it just speaks to maybe the ingenuity needed to do well on an island in this isolated environment that you have New Caledonian crows and Hawaiian crows, both being the tool users of the corvids for sure. Yeah.

Claudia Wascher: Yeah. Also, fun fact about this. If you put them on a phylogenetic tree, so if you look at their relatedness, those two species are actually not very closely related. So, for example, the rook... which is a very common European species, which is not a tool user, is closer related to the Hawaiian crow compared to the New Caledonian crow. And yes, and this is biologically incredibly interesting because that's where we can really tell that it's probably not the last common ancestor, which was a tool user, but it's much more likely that the ecological environment, so that the living on the islands, that there's something there which caused them to use tools.

Scott Taylor: Yeah. Yeah. And the ingenuity piece of this group of birds is fascinating. Know, even the crows that figured out like, okay, I can drop a, like a walnut at an intersection. The cars will drive over it. Open that for me. I'll wait till the light is red and then I will fly down. Like that is just so incredible and requires such a set of decision-making things to get that food. It's just amazing.

Claudia Wascher: Although, and I will say from a cognitive perspective, that's also something which I can almost bust for you. And this could have almost become a...

Scott Taylor: Oh, really? Oh.

Claudia Wascher: Fact because yes, they do this. So they throw or drop walnuts on roads and then cars will pass by. But actually the learning, okay, I'm going to stop until the light turns green or the light, it depends a bit on which perspective you look at. So the light for the cars turns red, so the cars basically stop. That can actually be very simple learning because cars obviously are dangerous for the corvids. So they will very quickly learn. They have to wait until the cars stop, otherwise they will be dead. So this is...

Scott Taylor: Yeah, there's strong selection to know what's going on there. That's right.

Claudia Wascher: But this is also something which we do have to keep in mind when we talk about cognition, that sometimes these things look very fascinating for us, and we are like, oh, the birds must be so clever to do this, where in fact it's often very simple learning, that they were just very quick at learning these type of things.

Scott Taylor: Yeah. And I mean, that even relates to flocking behavior. We've talked about murmurations on the podcast before and these groups of birds, it looks like this complex decision-making to fly around together, but it is very simple actually when you get down to the physics of it. So that's a very good point. So there are around 130 species of Corvid depending on, you know, classification, but around 130 we'll say, and they're on every continent except Antarctica. What do you think it is about this one family that makes them so good at living almost everywhere?

Claudia Wascher: And I think part of it is the flexibility and this ability to adapt to all sorts of environments. And it is really interesting because you do find a lot of variation in corvids when we talk about also distribution, for example. So some of the species like the Eurasian jay, but I think also the American crow, they are very broadly distributed. So they're very wide distributions, you can find them really over large areas, a whole continent at times. But there are a lot of corvids species. Actually, the majority of corvids species, we know almost nothing about them. So it's also very fascinating that there's still a lot which we absolutely don't know. Another thing which I think I should highlight is also the sociality of corvids. So that's something which I investigate myself. So I'm really interested. But basically, all corvids are social and are often highly social. So they live in groups or they form long-term relationships. So they really form... very valuable relationships with other individuals, which they really maintain over years, where they memorize other individuals in the group. And also they show certain behaviors. So we know, for example, that common ravens, that when they are in fights with other individuals, which they are friends with, So they have this valuable relationship when they fall out in a fight. After the fight, they show specific behaviors to kind of reconcile. So they really show like, no, you are valuable to me. I appreciate our friendship. So please don't be mad at me for too long. Sociality is quite flexible. So there's one really interesting example from here in Europe, which is the carrion crow, which is probably a very similar species to the American Crow.

Scott Taylor: Yeah. Kind of see them in the same places. Yeah. Same habitats also in cities and things like that. Yeah. Yeah.

Claudia Wascher: Yeah. Exactly. And carrion crows, over most of Europe, are territorial breeders. So that means they're in large flocks when they're juvenile, but then when they pair up with a pair partner, they split up and they start to defend the territory where if other individuals go into the territory, they would be aggressive and kick them out. But there is one very well-described exception in northern Spain, and there the carrion crow is a cooperative breeder. So that means that young remain in the territory often for many years and also feed offspring. So often you find groups which are three to nine, ten individuals there who help each other to raise offspring.

Scott Taylor: Yeah, I think the cooperation piece and social piece of these birds, I think, is really what captures our imaginations and our interest as humans, which we're also very social. We also have frenemies or friends where we have issues and then have to make up and make sure they know we still love them. A common question we get asked by folks they're like I want to learn more about crows and ravens and I really want to become friends with them And there's all these tips and tricks people have, like, well, you should try to give them some dog food or cat food, and then people want them to, in turn, bring them gifts. I think it kind of comes back to that social piece.

Claudia Wascher: Yeah, and I would say I strongly advise against this because.

Scott Taylor: Yeah, I don't think it's...

Claudia Wascher: A student of mine a couple of years asked me a question. She was like, yeah, she had a crow who was always knocking on her window and The crow was very persistent and basically woke the student up very early in the morning. And I was like, I'm really sorry, but probably it was quite likely a case of somebody was friend with this crow before you probably has fed the crow. So it learned there might be food there. And then they can become very persistent up to aggressive. And I think we are joking about it. But one important aspect about corvids is they're neophobic generally. So... also because they have been hunted for long times in large parts of the world. They generally are afraid of new things. And that's probably also part of the solution why they are so successful, because they really can learn quite strongly about dangers and can avoid dangers. So if something is new at the beginning, they would look at it quite with some suspicion. And this includes humans. And I think in living together with corvids, this is actually a good thing that corvids generally keep a bit of distance to us humans. Because if they don't do, they become aggressive and nasty because they will want food and they will not understand that some people don't want to give them food. And they will quite literally attack people. I mean, an interesting example about this, and that's also maybe a fun fact, because corvids are this group of, you already said it before, ravens, crows, jays. But also magpies. So there are three or four magpie species around the world. However, there's also the Australian magpie, which is quite famous for actually attacking people and flying at people, basically. However, the Australian magpie, careful, is not a corvids species.

Scott Taylor: Not a Corvid.

Claudia Wascher: They're another family but the interesting bit is that Australian birds generally are often less neophobic probably because this history of hunting is missing so in Australia you can kind of see and observe what happens when neophobia is missing from birds and what happens is they attack humans and are territorial towards humans and I don't think we want to arrive at a situation where territorial crows during the breeding season attack humans because they are defending their territories.

Scott Taylor: Yeah, then we would just have Alfred Hitchcock's movies coming to life, which you could imagine when you have a big murder of crows, which we're starting to get now. It's the fall here in Denver, and we get really large murders of American crows flying around the city. And yeah, they were... If they are directing their aggression towards people, it would be problematic. The most recent time I kind of experienced that was we went to Tanzania over last winter break and we were on Zanzibar where the Indian house crow has been introduced and it's kind of this, it's a pest now and they're very successful. They're very social. They're really good problem solvers. And the resort we were staying at had all these strategies to keep them out of the dining hall, which is this open air thing, which is what you'd want on a tropical island. But these crows, it was incredible to watch their, like you could see them sitting there, like figuring out how they were going to get the food, especially they would target children. Because children were way more likely to just get scared and run away. And you could see over the course of this week that they had all their little strategies for messing with people, which was impressive.

Claudia Wascher: Yeah, so I strongly recommend not to try to make friends with crows.

Scott Taylor: Yes, I know. I know. It's this thing that people just really want. But I agree. It's cool to watch them and observe them. And they are fascinating birds, but they don't need to be our friends.

Claudia Wascher: Corvids are songbirds. I always like to emphasize. So their vocal communication plays a really important role in their everyday social life. And we studied this by recording audio recordings of these crows again for a long time. And you try to record thousands of individual calls of all these individuals. And then we have a specific technique, which are playback experiments. So we literally would play specific types of calls back to other individuals and basically see how they respond to it and from different responses. You can then kind of try to tell and judge what they are kind of thinking. So in this specific experiment artificially in the experiment, made some individuals reliable versus unreliable sources of information. So this was a captive group of crows. To these groups of captive crows, we then played back other crows which they didn't know. So those were crows recorded somewhere completely in a different location. And we've experimentally made some of these crows reliable cooperation partners. And the way we did it is it was a bit of a mean experiment to a degree. So we actually put a dead crow in one... area of the aviary, which was separate to where the crows were, but the crows could kind of watch it. And seeing a dead crow for crows is something really stressful and something they really respond to. So they're really alarmed, of course, because a dead crow basically might mean that there's danger for them. So we've paired this dead crow with a couple of other crows which were unfamiliar to our captive crows. So those were reliable, a reliable source of information. So when these crows called, so we played back these calls that meant there's danger versus a couple of other individuals, we played something back and we didn't put anything dangerous there. So for our captive crows, it kind of looked like, oh, these are really unreliable because it's kind of a crying wolf thing. So, yeah. So they are alarm calling, but there's nothing there.

Scott Taylor: Yeah, I was just going to say that. Yeah, crying wolf experiment. That's cool.

Claudia Wascher: And over some time, we then saw that they were actually reducing their own vocalizations when the reliable crows were calling, which kind of makes sense if you think about it, because they probably were like, okay, we all shut up now and listen what this other individual is saying, versus if the unreliable crow was calling, they were just like, okay, there's no point in listening.

Scott Taylor: When you were playing those either reliable or unreliable individuals, was it the same kind of call for all of them? So you standardized like it was a certain kind of vocalization, but there were enough little differences based on who was making it that they could key in on that. That's so fascinating.

Claudia Wascher: The way we recorded these calls was exactly the same. Actually, the experiments have been conducted in Spain, so in the Spanish population, which I mentioned before, but the individuals have been recorded in Austria, so from the other population. In Austria, what I actually did to record these calls is I held up a black book. Which is, again, quite funny because corvids, you think they're very clever, but for example, they really do not like black things. And I've already mentioned seeing a dead crow would alarm them. And they respond very similar just when you hold up something black, which... isn't necessarily that clever, but I literally have elicited these alarm responses by holding up a black book.

Scott Taylor: Interesting. To try the black object thing the next time I see a group of crows here and see if they have like a geographically consistent reaction to just a black object. That's so interesting. Has anyone ever figured out like for a specific species of crow or raven, like what their actual full vocal repertoire is?

Claudia Wascher: Yeah, now you're hitting a really sore spot for I might cry and go home now. It is really difficult. So some papers say... jay species have two to three different call types. I think there's one paper which says it's almost a hundred different call types. And this is a bit of a problem because the way different people categorize different call types varies quite a lot. And the reason being that crows have very graded calls. So a lot of their call types, it's not super distinct. So this is call type A, this is call type B. But then they do something like... Okay, I'm not sure it sits somewhere in the middle, and I'm not quite sure it might simply be a bit different because it's a smaller individual or male versus female, young individual versus old individual. Or is it actually a different call type? At the moment, I'm also collaborating, for example, with the Earth Species Project, which you might have heard of. They're actually trying to really apply very new machine learning and the newest machine learning algorithms and methods on the corvids calls. So we've just tried a couple of weeks ago, actually, so it's very fresh. I again went back. So they ran an automated classifier, which basically then came up and said, these are the different call types I'm suggesting you. And then I went in manually and tried to search them and order them. And then another person tried and was like, no, I can absolutely not replicate what Claudia did. So it is extremely difficult. And another complication is that crows have very so-called noisy calls. So what you find in them are so-called nonlinear phenomena. So if you look at the spectrogram, it's just, yeah, there's a lot of noise. So you don't have very clear harmonic, a lot of songbirds. Have these harmonies which you can very nicely track in their calls. And then based on how these look like, you can classify them quite easily. Crows don't have them. So the calls just look all over the place. It is actually really interesting because... traditionally for a long time in biology, we've thought that this nonlinear phenomena is just noise in the call, basically. So the assumption really was that it just happens as a kind of a byproduct. So it happens, for example, a lot in stressed individuals and baby cries have a lot of noise, for example, in them. But now we're starting to look into it a bit more. And kind of think that maybe there's some biological function there. And if you think about baby cries, the biological function clearly is it stresses the listener out and somebody will start caring for this individual. So it might very well be that in corvids also these... chaos in the calls, that there is some sort of biological function there, for example, raising attention from conspecifics to certain things. And I do have another fun fact around this, because while doing this, when we did these classifications, there was one call type which was really clear, like very clearly identifiable. Much less noisy and it was all mimicry so it was all corvids mimicking birds of prey which is just which is just the most frustrating thing because it basically means that they can absolutely be very clear and produce these calls which are absolutely easily classifiable they just don't do it most of the time.

Scott Taylor: Yeah. Yeah, I mean, I would say that nine times out of 10 that I hear a red-tailed hawk in my neighborhood, it's a blue jay. And it's perfect. It's a perfect red-tailed hawk. I get tricked. I look up and there's just a little grinning blue jay looking down at me who's just scared all the birds away from a feeder. But you don't only work on crows. You've worked on other groups of birds as well. And you did specifically a bunch of work on geese where you were looking at their heart rates to try to figure out like what was going on, how they were maybe feeling about a certain situation. And can you tell us a little bit about that technique, like measuring heart rate, what you can infer from that? And then whether this is something you would try to work on with crows or not?

Claudia Wascher: Yeah, so the geese study. So basically our question around this was their social behavior and how social interactions affect heart rate. And it was really interesting because one thing we've seen is that social interaction massively affected heart rate. So basically...

Scott Taylor: Yeah. I mean, it does for me. That makes sense.

Claudia Wascher: So yeah, during aggressive encounters, heart rate was much more increased. And then you can kind of estimate how much the kind of physical involvement might contribute to this. So you can kind of look. You know, I mean, geese sometimes they have these really intense fights, which are extremely physical. So there's no question like, yeah, heart rate increases during this, of course, because they are physically active. But there are other situations where they are much less physically active and heart rate still increases. And that's basically indicative of emotional arousal. So you said it right there. Social interactions affect your heart rate. So we do know. That humans and many other animals increase heart rate as one physiological characteristics of emotion and feeling a certain emotion. So one of the interesting bits really we recorded a number like hundreds of situations where the geese were just sitting around in the area so doing nothing and not behaving to anything but heart rate still increased and we figured after a while there was really an increase to watching certain interactions. So if something happened in their environment, they increased heart rate, although we couldn't see any changes in behavior. And quite even more fascinatingly, we've then shown that If a pair partner or a family member was involved, so if the interaction had a really high relevance for them, they increased their heart rate even more compared to if it was a non-affiliated individual. And that's really cool because that's a characteristic of emotional contagion, for example. So really, like... basically picking up emotions from other individuals. And again, that's something which is relatively rare in non-human animals or rarely shown in non-human animals. So yeah, I'm very interested in emotions in animal or emotional responses. The tricky bit is how do we study emotions in humans? You can ask them. You ask them, how do you feel about something? Now as a next step is trying to measure emotions or infer emotions also from the behavior of the animals. And to a degree, you can do this because, I mean, I'm absolutely convinced that I can tell. Anger in corvids, for example. I always knew when my captive crows are angry at me. They do something in German, we call it Kugelkopf, so basically fluffy head. So if they're excited about something, they fluff up their feathers on the head. So never approach a crow when they have a fluffy head. You might regret it.

Scott Taylor: I think, you know, you've spent years listening to corvids communicating with one another at this point. And I'd love to hear from you, like a story from the field, something you didn't expect. I mean, I'm sure there's many things crows have done that you did not expect. Bring us into the field with you on one of these observations.

Claudia Wascher: Into the field so one particularly striking one again back in Austria at the research station I've worked for a long time some of the corvids there learned to mimic humans which again sometimes so actually and we've mentioned mimicry before so corvids have very good mimics we have just published a paper recently where we show that it's quite likely that all of them have the ability to mimic. It's just a question on how much they actually use it. So at a research station, they sometimes mimic humans. And there was one particular raven who always did it when people didn't look at the aviary. So basically you were sitting around the house and suddenly hear somebody and go, who's at the aviary? There shouldn't be anybody with the ravens now. And then if you looked, there was nobody there, but it was the raven actually mimicking.

Scott Taylor: That's awesome.

Claudia Wascher: And we did get another crow because all our crows back in Austria were rescue animals, basically. So many of them came from animal shelters in the areas. And we once had a family from Germany approaching us, and they had a carrion crow in captivity for 20 years. So when we got the bird, he was... It was 20 years. And it was a really sad story at the beginning because they had this situation where they hand raised the crow and they wanted to release him first. But he started to attack because he was not afraid of humans. So he started to attack the children in the neighborhood. So they had to basically lock him in a budgie cage for 20 years.

Scott Taylor: Oh, wow. Yeah, they do live so long. Yeah.

Claudia Wascher: Which really is not welfare-appropriate keeping conditions for a crow. So the son of the family just wished a better life for him, so they basically agreed to rehome the crow with us. But when he got him... got him he did say a couple of words and amongst other things he said his name which was Hugo and he always it was also funny because he always said it in a very aggressive way so in the voice you could already tell it was a Hugo So I absolutely, I guess my working hypothesis is that his human hand raisers, they probably every time he did something in the flat, he destroyed something or something like that. They probably went at him going like, Hugo! And then he imitated this very aggressive context. In the group we had at the time, all the individuals were much younger. They were one or two years old. And as it is in corvids, at the time, they look up to older individuals. So everybody looked up to Hugo. All the females wanted to pair up with him. All the boys wanted to be like Hugo. So after a while, he paired up, which I was so happy about it, that at this point, this old age, he still found a partner and he found love. And then when they pair up, they do become aggressive towards other individuals. So we had to remove Hugo and his new partner and move them somewhere else. And at the time when Hugo was removed, all the other crows started to say Hugo too. So everybody imitated it. So they've socially learned to say the same thing. But as long as the dominant individual, the older individual was in the group, nobody dared to use it. Nobody said it. And this is known that in crows, dominant individuals, for example, vocalize more compared to subordinate individuals. So as soon as Hugo was out, everybody else in the group was saying it. And we had, for years, we had crows who said Hugo.

Scott Taylor: That's so fascinating. It's so interesting that they wouldn't do it till he was away.

Claudia Wascher: He had a bullet in his wing so somebody really shot at him so a little small lead bullet and he also died of liver failure and this could be the lead bullet poisoning him but also Hugo really liked to drink so whenever we had booze...

Scott Taylor: Like alcohol? What? Hugo sounds like such a fascinating crow.

Claudia Wascher: I don't even want to know how they kind of trained him on the alcohol.

Scott Taylor: Would he like drink beer?

Claudia Wascher: And I don't remember, I think Prosecco. I think we got, because we had Prosecco once close to the aviary and then he came and had his beak in our glass a bit too quickly. So we don't know about the beer.

Scott Taylor: That's hilarious. What a refined like little Renaissance crow just drinking his Prosecco and yelling his name angrily. That's amazing.

Scott Taylor: We've reached the part of the show we call That's B.S., or That's Bird Stuff, where we give our guests an opportunity to debunk a myth that ruffles their feathers. So, Claudia, what do you want to call BS on?

Claudia Wascher: Yeah, I had a bit of a difficult time here because Alex Kacelnik used the BS I wanted to use. So again, I strongly recommend people to listen to that episode. And the second BS I'm using now is the thought that corvids would hold grudges against individual humans. Which we don't have any evidence for that this is actually the case. We do know that corvids are very good at learning dangerous humans, for example, from not dangerous humans. And they will learn very quickly when individual humans are nice to them and then probably react in a certain way. But I'm pretty convinced that they don't hold grudges in that sense.

Scott Taylor: Well, that's a great BS. Thanks so much for joining us. It's been super awesome to talk about these fascinating birds. I appreciate getting to know more about them from you and that you took the time to join us. So thanks for being here.

Claudia Wascher: Yeah, thanks very much for having me and this was a lot of fun.

Scott Taylor: Awesome.

Scott Taylor: Birds are dinosaurs, and around here we like our snacks, so we end each episode with a dinosaur nugget. Today's nugget is, crows don't have facial expressions the way we do, but that doesn't mean you can't read their mood. Claudia says her captive crows had a clear warning sign. When a crow gets worked up, it fluffs up its feathers on its head. In German, researchers call this Kugelkopf, which roughly means fluffy head. Her advice is simple. Never approach a crow with a fluffy head. You might regret it.

Scott Taylor: That's a wrap on this week's episode. Okay, but why are we obsessed with crows and ravens? If you enjoyed it, follow, subscribe, and leave us a review wherever you listen. Claudia says crows don't hold grudges, but I do. Five stars, please. We'll catch you next time. Byeee.

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.