The Mysterious World of Owls (with Jennifer Ackerman)

Sep 23 2024

81rk6XdRHsL._SY522_.jpg An owl will eat a rabbit whole, but owls can't digest the fur or the bones. So how do they survive? Why do their eyes face forward rather than to the side? Long-eared Owls don't have ears, so what's up with the name and how do they hear? How can dogs help us track owls--that seems impossible. Owls don't make nests, so where do they live? Listen as Jennifer Ackerman, author of What an Owl Knows, talks about the book with EconTalk's Russ Roberts, peeling back the feathers to reveal the astonishing biology and behavior of owls, as well as the amazing stories of those who love and study them.

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Time	Podcast Episode Highlights
0:37	Intro. [Recording date: August 29, 2024.] Russ Roberts: Today is August 29th, 2024, and my guest is award-winning science writer and author, Jennifer Ackerman. Her latest book and the topic of today's conversation is What an Owl Knows: The New Science of the World's Most Enigmatic Birds. Jennifer, welcome to EconTalk. Jennifer Ackerman: Thank you so much. It's a delight to be here.
0:58	Russ Roberts: What a fun book to write--and to read, by the way. Tell us about the process of how you came to spend the time you did with owls and what it was like. Jennifer Ackerman: Yes. So, my first close encounter with an owl was some years ago. When my children were little, we put an owl box on the maple tree behind our house. And, it was very close, easy to see from our kitchen window, nothing roosted there for quite some time. And then, finally, an Eastern screech owl showed up. And this little owl would roost in the box with just its head showing--its little round head. And, the girls were just fascinated. They were about seven and nine at the time. And, I would try to see this owl come and go, but it was so stealthy, I never saw it either enter the box or leave it. But, often in the morning my girls would come down for breakfast and out of the hole in this box would be hanging, say the wing of a blue jay or the tail of a mockingbird. And one time it was a whole mourning dove. And then, this thing would jerk, jerk, jerk right into the box and disappear. And the girls were, like, 'Mom, what is this?' It was their first lesson--and mine, really--on a top of the line apex predator. And, I was just fascinated by the idea that this little owl was coming and going in the night and coming up with this very large prey. When I opened the box finally after the owl had left, it was filled with feathers and all kinds of little bones and things. So that was really my first introduction. And then, I thought--I've written about birds now for more than 10 years--and I got interested in the idea of really delving into a bird family. And, the group of owls, it's just so diverse. They're just so unique in the bird world. They're these very skilled night hunters. They have this eerie, quiet flight and these quite extraordinary senses. And also, we humans have really been obsessed with these birds for literally tens of thousands of years. So, I thought: Well, it would be just really interesting to find out what we actually know about owls. They're difficult to study and what have we learned? Russ Roberts: And, as you alluded to there, they're different. They don't have one behavior, but they have many things in common. One is the predatory aspect of--you call them the 'wolves of the air.' Do anything--we'll talk in a minute about what they eat. Does anything eat them? Jennifer Ackerman: Oh, yes. Especially when they're in egg form or when they're chicks: they're vulnerable to all kinds of predators, snakes, raccoons, skunks, other birds of prey. And, the little ones--the little owls--you know, they range in size from the elf owl, which is just about the size of a little pine cone--it's really a little nugget of a bird--all the way up to the Blakiston's Fish Owl, which is the biggest owl in the world, and that's about the size of a fire hydrant. And the bigger owls--Great Horned Owls, Eurasian Eagle Owls--those will eat smaller owls when they're adults, these little owls. So, the little owls are subject to predation from all kinds of birds of prey. The bigger owls, really not so much. When they get to be full size, they're pretty much king of the playground. Nobody goes after them.
4:48	Russ Roberts: One of the puzzles that I had reading your book, and we'll talk later--I've got some owls in my life right now near my office, which is really extraordinary. Those owls near my office sit motionless all day long, as far as I can tell. They may be playing cards when I happen to be working in my office. But when I go by their tree--and I tend to greet them; and there's anywhere from two to four birds in the tree on any one day--they're just motionless. They're sitting there inside the branches of a partially dead cypress. So, it's a fantastically interesting tree. On the outside most of it is really, really thick. There's no way you could get in there. But there's a dead part. And the birds have found their way up into the branches. They're up quite high--a number of them, of the four. And, they sit there motionless. And, as you point out, they're incredibly well-camouflaged. These are Long-eared Owls. They are really hard to see. When you point at them and show them people they can't see them. And, eventually you learn to recognize them. Long-eared Owl by Anthony VanSchoor; Cornell Lab of Ornithology \| Macaulay Library Enlarge But I'm curious why they're so camouflaged in the daytime. So, I don't think they have any predators here [Israel]. They may in other parts of their habitat. They're pretty big. They're, I don't know, a foot-plus tall, probably, at rest. So, I can't see them in the daytime when they're doing nothing. And, at night they're killing things--which, we'll talk about what they kill. But, why do they need to be camouflaged in the daytime? What are they worried about? Jennifer Ackerman: Well, the truth is Long-eared Owls are prey for bigger birds of prey. So, they are being still to camouflage themselves. And, I know what you're saying, because when I was in the field once in Montana, we were trying to trap a Long-eared Owl that was roosting in a gully, and my job was to keep my eyes on this owl while the team was setting up the mist net and getting ready to try to flush the owl and catch it in the net so they could band it and take blood samples and things. I really failed at my job. I mean, every time I just turned my attention away for a second, I had trouble spotting this owl again. As you say, they almost look like a broken branch. They get very tall and thin. They have these plumicorns on their heads, which they make erect, and that makes them look even more vertical. Sometimes those plumicorns, they will sway in the wind like a branch would. Just so thoroughly camouflaged. But it is, again, as I say, because they can be targeted by bigger birds of prey. Russ Roberts: So, let's stick with the Long-eared Owl for a minute because it's quite fascinating. The Long-eared Owl--which listeners can Google and viewers can Google and find anywhere you want [also see photo accompanying transcript--Econlib Ed.]--it looks like it has these little tufted ears rising up from the top its head. Those are the plumicorns, right? Jennifer Ackerman: Correct. Russ Roberts: They're not ears. It's a misnomer. They're not Long-eared. They're Long-plumicorned. Jennifer Ackerman: Exactly. Russ Roberts: Explain. Jennifer Ackerman: Exactly. They look a lot like mammal ears, and that's true for Great Horned Owls, too, Eurasian eagle owls. Any of those owls with those plumicorns, you think, 'Oh, well, that's got to be their ears.' It's not. It's really largely about a camouflage. But, an owl's actual ears are really just holes in the sides of its head and they're covered with these specialized feathers that allow sound in. But it's just a hole, and you can look into that hole. So, yes: those Long-eared Owls are definitely misnamed. They're Long-plumicorned Owls.
8:59	Russ Roberts: And, one of the coolest things is that the ear openings, which--the things they hear through, which are not ears the way humans have them or other mammals--their ear openings are not symmetric. Explain why. At least on some owls. All or some? Most? I don't know. Jennifer Ackerman: Some owls. So, particularly Great Gray Owls, Boreal Owls, Barn Owls. These are owls that hunt primarily by ear. And, they hunt at night. And their ears are asymmetrically placed. One is higher than the other. And, that gives them the ability to really precisely locate the source of even the faintest noise in three-dimensional space. So, to accurately locate its prey, the owl's brain actually compares the sounds that are arriving at each ear--first of all, how loud they are and also which ear detects them first. And, it's the difference in the time of arrival of sound waves between the two ears that helps the owl gauge the exact horizontal location of the sound. And then, it's the difference of loudness that helps it determine the sound's elevation. And, where that horizontal location and elevation intersect, that's where the owl actually directs its strike. And, it does all of this sound processing within about 20 microseconds. So, it's all happening really, really fast. Russ Roberts: And, some owls like the Snowy Owl can find a vole, which is a small rodent, underneath the snow because it can hear the rustling of the crystals of the snow, right? Jennifer Ackerman: Yeah. So, this is actually the Great Gray Owl, and from a distance of 30 feet, this owl can detect the presence of a vole or a mouse or small rodent tunneling a foot and a half deep beneath the snow. So, this is really quite remarkable. And, what the owl does is that it will fly from its perch and hover over the sound, and then it just makes this dive that's incredibly accurate. The poor little vole has no idea what's coming. And, the owl inevitably just dives through the snow and comes up with its prey. It's really remarkable. Russ Roberts: Have you seen that? Jennifer Ackerman: I've not seen it. I've seen many videos of it, but I've never seen an owl actually go through the snow. Most of the field work that I've done was not in the winter. Russ Roberts: But, I do want to mention: You did a lot of field work. We didn't get to talk about that. You spent a lot of time with the greatest experts in the world in their quest to understand this diurnal, mostly nocturnal, corpuscular bird that is a bit mysterious. Jennifer Ackerman: Yeah. So, I was really lucky be with owl experts all over the world and spent time in the field with some of the best of them. And, we were in Montana, Europe, Brazil. These are wonderful researchers. These owl people are just crazy dedicated to their work, and it's really difficult work when you think about it. These owls are elusive. They often live in very remote locations. They're active at a time when access to field sites is difficult. So, these people are really super-dedicated. And, their work is, I think, some of the most difficult bird research work in the world. It's very difficult to find these birds and to capture them. And so, it was really a thrill to be in the field with some of these people. I also spent time with a group of community scientists. These are ordinary people, volunteers who give their time to owl research projects. And, there were a couple of them that were just really amazing to work with. There was a heart surgeon, and he devotes his time--now he's largely retired, but he was doing this while he was a surgeon as well--studying the Northern Pygmy Owl, the courtship and mating of these birds. And now he's one of the world's foremost experts on these little birds. And, another one was Julie Kazmierczak[?sp.?] who is the coordinator of the emergency department in a major hospital in Richmond, Virginia. After a full day of work, at night, she goes out and bands Northern Saw-whet Owls. All night long sometimes, and then we'll go back to work in the morning. She's just phenomenal. So, I got to spend time in the field with some of those people, too, and just saw some of the really amazing dedication. Russ Roberts: Before we leave the vole, I do want to mention that one of my favorite poems is called "The Heart of the Backlog." It's by Robert Penn Warren. Unfortunately or not, it's not readily available online. If you subscribe to the New Yorker you can find it. I was going to read a part of it, but I realized, one, reading an excerpt doesn't do justice to this particular poem, and it's one of the scariest poems I've ever read. And it involves an owl taking a vole. It's really a spectacular poem, but I encourage poetry lovers to go find that poem.
14:24	Russ Roberts: Let's go back to the hearing and the sight. Until I read your book, I never realized that owls' eyes face forward. Of course I know that, but I never thought about it. And, it is part of the reason they see so well and can hunt at night. It's also part of the reason that human beings find them so fascinating because they look like us to some extent, unlike other birds. Jennifer Ackerman: That's right. It's very unusual in the bird world to have forward-facing eyes. Most birds have eyes on their sides, and that gives them better peripheral vision to pick up the presence of predators. But owls, as you say, have these forward-facing eyes, and it really helps them in the kind of binocular vision that they need to zero in on moving prey. Interesting that their eyes are actually locked in place. So, they have tubular eyes and they can't move their eyes. They can only move their heads. Yeah. So, yeah--in order to keep something in their field of view, they have to actually move their head. So, you stand near an owl and it can bob and circle its head trying to get a good look at you. And, while it's not true that owls can turn their heads 360 degrees around, they can turn them about three quarters of the way--270 degrees--which is very impressive. And, it's about three times the twisting flexibility that we humans possess. So, really remarkable.
15:57	Russ Roberts: Let's talk about their eating habits, which--I warn parents listening with small children that sometimes topics have adult themes. This is not one of them, but it is a little bit gruesome. They prefer to eat living versus dead, and they eat them at a go. They just take them in. So, talk about the range of things that owls eat and how they manage that. And, the strangest part, which you will explain for us, is: they don't eat all of it. So, go ahead. Jennifer Ackerman: Yeah. It depends on the size of an owl. There are some owls that eat insects--the little ones--all the way up to, say, a powerful owl that will take a possum. And an Eurasian Eagle Owl will actually take a small Roe Deer. So, there's a huge range of prey. Many owls will eat small rodents: they'll eat mice foals, rats. They'll eat rabbits. Russ Roberts: Lemmings. Jennifer Ackerman: Lemmings. Yes. Snowy Owls, primarily 99% of their diet when they're breeding are these little rodents called lemmings. And, they will also eat birds. And, as I said, some owls will eat other smaller owls. And, often the smaller prey, they will eat whole. And, if you think about taking in, say, a mouse or a rabbit, it's going to have fur and bones and teeth, and those are things that the owl can't digest. So, the owl will eat its prey whole, and then the indigestible parts--all of these bits of fur and bone and teeth--the owl will compress in its stomach. And then, once it's all compressed in a tight little package called a pellet, the owl actually moves that pellet up through its esophagus and out of its mouth. If you look at photographs of an owl ejecting a pellet, and it really is kind of gross. But, the fact is that these pellets are full of really interesting information about what an owl eats. And, in some schools, the pellets are dried and sanitized and kids get to dissect them and figure out what that particular owl was eating from the little bones, the little skulls, even the teeth. Russ Roberts: Quite extraordinary. Now, let's go back to my friends in the tree here. My four feathered friends. As I said, they don't move during the day. They just sit there, at least when I go by. I assume they're busy at night and they're looking for prey. When they find that prey, do they eat it on the spot? Sometimes they're taking it back to--the male is the primary hunter I think, when the female is nesting, at least? Or what's the word I want? Taking care of eggs. So, the male goes out, catches something--something he's going to bring back to the female or the chicks. But, let's say he's not doing that. Does he eat out on the road? Is he doing takeout? Does he bring it back at night and have some in the morning? And, the real question is: Should I see pellets at the base of that tree? Jennifer Ackerman: Well, I would say in answer to your question: All of the above. Some of them are eating their prey on the spot. Some of them are taking them to a favorite roost. Oftentimes, one of the best ways of finding an owl is to look for pellets on the ground. And, owls do have favorite places to roost and to eat their prey, and then they will drop the pellets at the base of the tree. And so, then you can look up just as you did and spot your Long-eared Owls based on their pellets. And, it depends on how hungry they are. And, sometimes they kind of stockpile prey. Like, Snowy Owls, when they have nests, will stockpile lemmings. And, Denver Holt--the researcher who has studied these Snowy Owls for 40 years--told me he found one nest where the owls had stockpiled 86 lemmings all piled up around the nest. And, the thing is: they know that these lemmings are not going to spoil because it's so cold in the Arctic so they're preserved, and then they get to feed the young, sort of lemming by lemming. Russ Roberts: Oh, you never can tell: when you've got a good Netflix series and you have a longing for a lemming and you want to have one handy. You don't have to go search for it, miss the second season, or whatever. They prefer, though, to eat them fresh. They don't like to stockpile, generally, right? Jennifer Ackerman: No. That's right. In colder climates, some owls will cache their food, but most will just eat them fresh. And, I once had--somebody asked me if I wanted to feed an Eastern Screech Owl, and I said, 'Sure.' And I kind of didn't know what I was in for, because what they gave me was a bag of very fresh, chopped up mouse parts. Very bloody, very fresh. So, I fed the owl little bits and pieces from this bag of carnage. But, yeah. So they really--and it's one of the reasons that owls do not make good pets--and there are so many reasons--but they like their prey, their food fresh. So it's not an easy task to feed them if they're in captivity. Russ Roberts: We'll come back to the pet thing, I hope, a little bit later.
22:15	Russ Roberts: But I wanted to ask about nests. Shockingly, most owls do not build nests. Correct? Explain what some of the--there's enormous variety, which you write about. Give us an idea of the range of ways that owls find homes. Jennifer Ackerman: Yes. So, they don't build their own nests. None of the species do. They take over the structures that are built by other birds, other animals. So, for instance, Long-eared Owls will take over the nests sometimes of ravens and magpies. The bigger owls, like Great Grey Owls, will commandeer old raven nests and hawk nests. There's a really wonderful species called the Burrowing Owl, which nests underground in the burrows of prairie dogs, armadillos. You know, whatever will dig a burrow itself, these owls will then nest inside those burrows. And, there are a number of small owls that nest in the holes that are by woodpeckers in trees, and they create little cavities, and the birds will nest there. Russ Roberts: They also nest in human creations, right? Jennifer Ackerman: Yes. Certainly in nesting boxes. It's one of the ways that scientists can actually really control some of their studies. And, the variables in those studies is by building nest boxes; and the owls will take to those. Russ Roberts: One of the things I loved that you write about--at surprising length; it's not long, but it's still surprising--is the virtue of a dead tree. You see a dead tree out in the world; and you think: You know, I was about to get rid of that. And, often they do: they make firewood or they do other things with it. But, as you point out, dead trees--and my neighbor owls here are a good example of that--this tree is not dead, but there's a big part of the tree that is dead, some of the inner branches. And they love it because they are perfectly camouflaged against that rather than the dark green foliage of the rest of the tree. But, a lot of owls nest in those holes that woodpeckers find in dead trees where insects are, that the woodpeckers are trying to get out; or that just happen from weather and other things. Jennifer Ackerman: Right. Yeah. And, one of the really, the favored nesting areas of Great Grey Owls--these big, beautiful majestic owls--is the top of a snag. A dead tree that's lost all of its branches, lost its top. And, it doesn't look like it's very comfortable. But the owls will nest on top of those dead snags. And, the snag often has a little bowl, and the owls will--yep. And, they'll nest there. So, I always tell people, if you want to create owl habitat, if you have any kind of piece of land, or you just leave those snags, as long as they're not threatening a structure or something, they are really wonderful sources of food for so many different animals, and certainly nesting for owls.
25:46	Russ Roberts: Let's talk about the sounds that owls make. I've always thought I knew what a sound an owl makes, which is 'whoo, whoo.' Right? They say, 'whoo.' And, we call that hooting. Turns out there's a big range of noises. Talk about some of those noises and why they're important. Jennifer Ackerman: Yeah. Well, as scientists have lately learned, a hoot is not just a hoot, either. Owls do hoot, but they have really elaborate vocal repertoires that are just teeming with meaning. So, they have greeting hoots, they have emphatic hoots, they have territorial hoots. And, as you say, they don't just hoot: they also chitter and squawk and squeal. And all of these different calls communicate very different information. First of all about the owl itself: they communicate information about the owl's sex, its size, its weight, its individual identity, and also its state of mind. And then, all those territorial hoots, those are the vocalizations that we hear most often. And, you say it's the hoot of an owl. It's really one of the few bird calls that most people know. And, owls are very territorial, and the way that they protect their turf is through this hooting. So, it's far better than an actual physical battle, if you think about it. Because, if an owl gets a talon in the eye, it's kind of game over for that bird. So, these birds, they defend their territory by hooting. And then they have all of these other vocalizations that are used in very specific contexts for very specific purposes. And, we have just been exploring some of the range of these vocalizations in different species and learning also that owls have very distinctive voices, just as we do; and that they can recognize each other by voice alone. So, they use that to identify kin, communicate with mates, allies, rivals. And, it turns out that researchers now can also identify owls by their unique territorial hoots. And, it turns out those are really consistent for each bird, and they're really sufficiently distinct from one another that you can actually fingerprint an owl--an individual owl--by its hoot. And that means, really, two things. It means that scientists can actually monitor the populations more accurately--and that's a really important tool for conservation. And also, researchers can kind of observe by listening who is mating with whom and whether pairs are staying together. And so, it's providing a lot of information. Russ Roberts: And you write about the technology that's being used now to analyze and using AI [Artificial Intelligence] in other ways to analyze the distinctiveness of those sounds. There's also a lot of hooting and chirping and chittering from owl researchers who are either trying to attract owls to catch them, band them, keep track of them. But, there's also folks who live with, say, an owl that was damaged--now might be used for educational purposes--an owl that was injured. And, that owl communicates with--especially if that human keeper was with that owl when it was near its birth--it sees the human as its partner, friend, whatever, and talks to him a little bit. So, talk about that side of things. Jennifer Ackerman: Yeah. So, people that keep captive owls--and they're often because these owls have been injured or because they're training them to be ambassador owls--owls that go out into community, schools, and to teach people about the nature of owls. One of the people that keeps an owl that I learned a great deal from is a woman named Karla Bloem, and she runs the International Owl Center, which is in Houston, Minnesota--not Texas. A little town in Houston in Minnesota. And, Karla adopted a Great Horned Owl named Alice. When Alice was, as you say, very little--and Alice now treats Karla as a mate, really, and hoots at her. And, in the beginning, Karla really didn't have a clue, like, how to hoot back to Alice. And, Alice got very upset with Karla, and at one point was on her perch and just smacked Karla. And, Karla was like, 'Well, I'm sorry. I don't know how I'm supposed to do this.' And it really launched this long study that Karla Bloem has done since, about the vocalizations of Great Horned Owls and what they actually mean. And also how to hoot back to her little partner, Alice. And it has turned out, really--I think Karla found there were 15 separate vocalizations in Great Horned Owls, and now she can hoot properly back to Alice, which is a great advantage. Russ Roberts: And, I think you're right, that Alice did not approve of Karla's boyfriends, but did approve ultimately of her husband. So, what happened there? What would go on? Jennifer Ackerman: Yes. Well, as I said, owls are very territorial, and Karla would tell you they're also very good arbiters of character. So, when Karla was dating, she would use Alice as a litmus test of whether the guy was okay or not. And, if that guy was not okay with Alice, she would dive-bomb him. And, it was not a pretty picture. But, when Hein, who is currently Karla's husband, came in the door, Alice was very accepting and actually favors Hein now over Karla. So, it was-- Russ Roberts: Karla okay with him? Jennifer Ackerman: Yes. I think she's a little jealous, but it's all right. She's willing to share, I think.
32:19	Russ Roberts: So I should tell listeners that: when I connect with a guest on Zoom and I explain how the program works and what we're going to do. And I usually give them some warning: if I'm asked about some topic I explain you don't have to answer every question. If you don't, we can edit that out. It's not a gotcha show. But I did not warn Jennifer that I was going to ask her to hoot for us. So: You can decline if you want. But I'm sure you worked on some of your skills out in the field and either as doing some actual field work, calling to owls to try to get them to come by or just out of a natural desire to be part of the orchestra. Can you do some owl sounds for us? Jennifer Ackerman: Okay. This is really not fair. Because this is not my forte. And, there are some people who are so good at it. Like, the people that work at the International Owl Center--they have to be so good. It's part of the job description that you have to be able to imitate hoots of different kinds of owls. The only one that I can do even remotely well is--well, I can do two. Long-eared Owls are probably the easiest on the planet because it's just 'whoo whoo whoo whoo.' Great-Horned Owls are: 'whoo, whoo-whoo, whoo whoo.' Russ Roberts: Nice. We don't get any chittering or chirping or any of the other more exotic noises. Jennifer Ackerman: I can't do the other stuff. I wish I could. And, I will say that a lot of people use either their own vocalizations--birdwatchers--their own vocalizations or what's called playback when they have a recording of an owl's hoot, to try to draw in the owls. And, the scientists do this and they do it in a very controlled way, and they do it for a very specific purpose. But, I really discourage people from using this technique to draw in owls, because it--as I said, owls are very territorial. It uses their energy. They think there's a rival in the area, and they'll come in and they'll leave their nest and exposed. So, it's not a good idea in general to try to draw in an owl this way. Russ Roberts: But, going back to my neighbors, the Long-eared Owls, I would love to hear them; and I have not. I assume they are quiet in the day. When do they--do they hoot? I mean, songbirds just sometimes seem to sing for at all kinds of times. Do they hoot at night? or do they hoot at dusk? If I wanted to hear them--I don't want to provoke them. But, if I wanted to hear them, when might I do that? Jennifer Ackerman: Well, I would suggest either very early in the morning before dawn or around dusk. And, you will often hear an owl hooting just before it's about to go out on its hunt. But it's not predictable. And, it depends on the species. And it depends on the situation. But, if I were you, I would perch somewhere near that tree before dawn, and I'll bet you'll hear that whoo-whoo-whoo of the Long-eared. Russ Roberts: And, will I have a chance then also, I assume to either see--will they hunt all night long? Will those owls return at dawn or will they have often have caught something at 11:30 and now be back in the tree making their pellets and having a party? Jennifer Ackerman: Yeah. Yeah. It's always really--you can't necessarily predict. Because it depends on how quickly they find their prey and again, how hungry they are, how long it has been since they've last eaten. And so, it's a little hard to predict there. And, as I said, with this Eastern Screech Owl, that box was right outside my kitchen window. And I just never saw the owl come back to it. You know, and, I did watch. So, I think that was probably all times of night that little bird re-entered the box.
36:37	Russ Roberts: And, we won't go into it in detail, but these birds have incredible facility in flight. They're famous, many of them, for being either near silent--some think they're literally silent. Some are skeptical about that. But they're obviously dramatically quieter than many other birds. You can find many nice videos on YouTube--which one of your researchers said may be doctored for silence. So, keep a skeptical mind: but they're definitely quiet. But, one of the things that strikes me about, again, my neighbors, is it looks like they can't get to where they are. They're sitting in this incredible thicket of dead branches and they're 20, 30 feet up the tree. I'm thinking, how did they get there? And when they leave, how did they get back? How do you fly in that ridiculous space? Are they climbing? What are they doing? Do you have any idea? Jennifer Ackerman: Sometimes they're climbing, but I had the same experience that you did. When we finally captured this Long-eared Owl in that gully that I was telling you about, I actually got to hold the owl and release it. And, this gully was just dense. Choked with shrubs. And, that owl, when I released it, she just silently just wove her way through that very dense underbrush and out of the gully. So, they are navigating these very dense vegetation--these trees--all the time. And, what's remarkable to me is, as you say, their flight is so quiet and that's largely because they have several features. They have a coating of velvet on their wings that quiet the sound of the feathers rustling against each other. And then, they also have what's called a comb across the front of the wing where the air meets the wing, and it breaks up any kind of turbulence that would make that swoosh sound that you hear with other kinds of birds in flight. And, the remarkable thing to me is that they can move amongst these branches and trees without damaging those feathers. So, it's really quite extraordinary that both the quietness of the flight and also the facility of their navigating these very dense vegetative environments. Russ Roberts: The other part that seems strange is that--you can again watch on the web those gorgeous videos of owls taking flight. And, it's not a small matter. If they have room, they basically hunch up what we would say are their shoulders, and the wings start to bend and then they extend, and they're very long. And, there isn't room in this tree for them to fly with fully extended wings. So, are they able to fly at all with partially extended wings? Jennifer Ackerman: Well, that is a really good question. I'm assuming so, but I don't know the answer to it. That is one of the other reasons that their flight is quiet--because their wings are so big in relation to their body size, so their flight is buoyant and slow. But, as you say, it's also kind of hard for them to get going. I had the joy of seeing Flaco, the Eurasian Eagle Owl who lived in Central Park. He was roosting in--he's the one that escaped from the Central Park Zoo, and the New Yorkers fell in love with him. And, he was this really gorgeous Eurasian Eagle Owl, full size. Magnificent bird. And, every day at dusk, he would leave this oak tree and he would just do exactly what you say, which is just partially extend his wings. And then, once he was free of the tree, he would fully extend them. So, I'm assuming he was able to fly with that partial extension.
40:48	Russ Roberts: Part of the book is the mystery of these birds, which are by definition mostly active at night, so hard for us to observe. And, a good chunk of what you write about is the challenge of that research agenda of trying to understand them better. And, that often involves trapping them, banding them, taking a blood sample, trying to find out DNA [Deoxyribonucleic acid] [Deoxyribonucleic acid] of the birds to see whether species are related or not. And, alongside that is this issue of: What's natural? That an owl runs into a car, or is hit by a car, is damaged. You mentioned at least one month--probably more hospitals where animal rescue takes place. And, do the folks in that field take about the ethics of that? To me, there's a certain--like, I don't have any love for voles, lemmings, mice, or rats, so--and I love owls. So I understand we want to save them and keep them alive and thriving. Emotionally, it's very powerful. But, trapping them in nets and subjecting them to procedures--not just, like, one. You write about people who've tried to find and band every owl in a particular area to do really quiet quality research. Which I get. Any--squeamish about that at all, either you or the folks in those situations? Jennifer Ackerman: I will say that, to the person, they are all dedicated to minimizing the impact of their work on the wild owls. And so they work very, very hard to keep the time that they have these owls in captivity. Everything about it, they really try to make sure that it's not a traumatic experience for the owls. And based on what I saw, these owls do fine. Once they're released, they have their band on. It doesn't seem to hamper their migration. They don't seem troubled by the tiny bit of blood that was taken. They seem to do just fine. And, somebody like David Johnson, who runs the Global Owl Project--he's the one who wanted to study every single bird in his area. He studied those birds long-term; and they are doing just fine. They are reproducing like crazy. He started with eight pairs; now he has, I think, 560 birds at his site. So, you know, I think the ethics of the study techniques: very, very well-developed. And, these people who are working with these birds are very highly trained. And, I think what they're learning is so important to preserving populations of these birds that it's really worth what I think is a very small risk that's taken to learn what we need to learn about how to preserve these birds' habitats. And, that's really the big one, because it's the biggest threat to owls right now. And, just understanding the populations, how big they are--we still don't know how many owls are out there. So, all of these research efforts are really contributing, I think, in a very important way to sustaining the populations of owls that we have on this planet. Russ Roberts: Yeah. I'm not judging them. It just crossed my mind, reading about their efforts. And I think about the zeal with which we as humans try to have no footprint on the earth--which I think is silly, mostly, because we're part of the earth and we are part of nature. And, I understand that a truck hitting an owl is not natural--it doesn't seem natural. But not is it really that much different from a predator. It's a different kind of predator. I don't want to see their habitat disappear. I feel differently about that, obviously. But, it's just kind of interesting that a lot of the folks that you spent time with see themselves as very much part of the natural world. And, write about it and speak about it. There are many beautiful moments in your book where people talk about what this work means to them emotionally, spiritually. And yet, they're doing something that is--in other settings we would say is somehow tampering. It's not that even that it would lead to bad outcomes for the owls. It just, like--it's just not--doesn't seem right. Again, I'm not judging them. I'm not saying that it's wrong. I just--I think there must be some tension in their feelings about this, I would think. Jennifer Ackerman: Yes. And, I think that's especially true for the young researchers who are just getting into the field. Many of them have--their training has been to sit quietly and observe owls for many, many, many, many hours. And, that's a very different kind of experience than actually trapping an owl and handling it and banding it. I do think that some of the young people do kind of struggle with that. But they understand the bigger mission. And their connection with these birds is, as you say, really quite extraordinary and profound and almost spiritual. And, I think they feel that they are learning something from these birds about how to be a good human. How to be subtle in the world and not stand out all the time--where there's so much pressure in society to stand out. And, these owls, they're so good at being quiet and discreet and subtle in the world. And, some of the young researchers I talked to said, 'Yeah, it's really taught me how to be in a different way.' And so, I think that's kind of marvelous. Russ Roberts: One more thing on the quest for knowledge in this dimension. One of my favorite things that you write about is the use of dogs to understand owls. It seems like there wouldn't be any use, but there is. Jennifer Ackerman: Yes. So, these are dogs that are trained to sniff out the pellets of rare owl species. And, these dogs can--the pellets actually do have an odor, which we can't really detect but the dogs can. And the dogs can be trained to detect one species of pellet over another. So, these dogs are used by their trainers to explore very remote areas looking for these rare owls. And what the dogs do is they go out into these areas. They find the pellets. And then they wait for their owner/trainer to come; and the trainer looks up in the tree and there are the owls. And they've done this in Tasmania with a Masked Owl, which is a very rare species, and then also the Northern Spotted Owl, they've used dogs to find. And the idea of one species of animal helping to find another, it's just so beautiful. And these dogs are really remarkable. They're so well trained and they're so adept at their work. There were many times when I wished I'd had one with me to try to find the owls in the wilderness with these researchers. But, uh, yeah. Russ Roberts: But the dogs don't eat the pellets. They just find them. Jennifer Ackerman: They just lie down next to them. And, yeah. And, they've been trained. There's a organization called Rogue Detective Team, and they look for rare species of all kinds, including mammals and insects. And, these dogs are trained to locate these rare species and then just leave them be and point their trainers in the direction of where these organisms are. Russ Roberts: Yeah. Sorry. Go ahead. Jennifer Ackerman: I just think it's an amazing--and it's not a common use, not a common way to find owls. Nut I think in certain circumstances it's very, very effective. Russ Roberts: Interested listeners, if you missed the episode with Rowan Jacobsen on his book, Truffle Hound, which is a similar thing of training dogs to find truffles and ideally not eat them because they're very valuable--the pellets, different kind of value.
50:08	Russ Roberts: Let's talk about the Harry Potter effect and Hedwig, which--wouldn't have seen that one coming. Quite strange. Jennifer Ackerman: Yeah. So, the Harry Potter effect, basically. it encouraged people to try to take owls themselves as pets. And, this was very common in the United Kingdom. And, unfortunately, as I said-- Russ Roberts: Because Harry Potter had this messenger owl, Hedwig, that -- Jennifer Ackerman: Yes. Will, they all had owls--of different kind. And Hedwig was Harry Potter's. A special Snowy Owl. And so, it was actually a male owl. Several owls played Hedwig in the movie. But, in any case, the books and then the movies really encourage people to try to take these birds as pets. And, they are wild creatures. They do not belong in homes and for lots of reasons. They hoot all night. They shred things with their talons. They poop everywhere. They eat raw meat. It's just not a good plan. And, as a consequence, after people found out how terrible these birds were as pets, there were all of these rehabilitation and refuge centers that had to be set up to take in the owls that people were then wanting to get rid of. And, it also fostered interest in pet owls in places like Indonesia and Southeast Asia where there are bird markets. People like to keep birds as pets. And, before the Harry Potter books came around that owls were just not part of the picture at all, but afterwards, they were very, very common in those markets. So, I think it had a really, really negative effect. I think that's dwindling a little, but it's still present in some places in the world. Russ Roberts: Well, at least negative on the pet side. I think it also romanticized owls in a really wonderful way. You write a lot in the book about superstitions and beliefs people have about owls as evil, bad luck, dangerous; and certainly the Harry Potter series, I think created a lot of love for owls. Maybe some of it misplaced for the pet project, but at least in general to care about them. Jennifer Ackerman: Yes. I think that's right. I think it did generate some real interest and love for owls. I just wish it hadn't had this negative effect at the same time. But, as a species, we humans have been obsessed with owls for a very long time, so this is not a new thing. I think we love them and in some places we fear them, but they're present in our art and our culture and our stories through the generations, in every part of the world.
53:24	Russ Roberts: I don't think you wrote about this. I may have missed it. Besides the front-facing eyes, the nature of the owl's beak in most species gives it the look of having a nose. And, I wondered--and again, maybe you wrote about this, I don't remember--but the beak itself, in raptors, as far as I understood it, is used often to tear flesh from a carcass or a living creature. It's not used for the kill. And, the kills that we've been talking about are with the feet, the talons of the bird. The owl though, at least most of them have this very sharp beak-ish thing at the end of what looks like a nose. What's it used for? Jennifer Ackerman: Yeah. It's not to kill prey. Owls also use their talons to kill their prey. Sometimes they'll use them to bite the back of the neck of prey. But, the main thing is they have really amazing feet and talons. So, their feet have toes that can swivel into an X shape. So, they have four toes, and that ability to swivel these toes into the X shape allows them to hold onto prey. They have a special--it's like a ligament that locks the talons so that they can actually hold heavy prey without exerting any energy. And, I think that's one of the cool things. And then, these talons are just razor sharp. You look at any of the researchers, the hands of the researchers who handle these birds--and they never handle them with gloves because they can't determine how much pressure they are exerting on the bird if they have gloves on--but their hands are just covered with talon gouges. They're very, very sharp. So, those little critters don't have a chance against those razor sharp talons. Killer talons. Russ Roberts: But unlike, say, an eagle that would tear its food with that beak, doesn't the owl usually swallow it whole? Or does it sometimes break it up with the beak? Jennifer Ackerman: It breaks it up with the beak. And also, if you think about an owl feeding it's young, it's tearing up those larger pieces of prey and making little chunks for the young to eat. Yeah. It's definitely using its beak to tear prey. Russ Roberts: You mentioned in passing the cat-ness of owls. When I was teaching my granddaughter to recognize owls--just owls--she once saw a Long-eared Owl in a book and she decided it was a cat. She was about a year and a half old and meowed when she saw the picture of the owl. And I thought, 'Well, that's a bad mistake.' And then I looked at it and I thought, 'No, it looks a lot like a cat.' Which is interesting. Jennifer Ackerman: Definitely. Especially the owls with those plumicorns. In the book, I write about this wonderful researcher at the Metropolitan Museum of Art who got interested in finding all the owl images at the museum. And the reason she did was because she said her cat looks just like an owl. So it's the other way around. She thought, well, there's something so catty about owls and she loves her cat. So, she went in search of these images in the museum and she found, I think, close to 600 of them in all different media and through the ages. So, really, really wonderful stuff. Russ Roberts: This is a G-rated [General-audience-rated] program, but there is a more adult-themed piece of your book. A page or so. Picasso had an owl; and some of his more adult drawings have owls in them, which is fascinating and cool. But, there's a lot of art that owls there make a casual appearance in the background. I think it's "Bacchanal with Owl," and I'm looking at it. I went and looked it up online. I'm probably not the first reader of your book to think, 'Well, let's see what this looks like.' And, I open up the image and I'm thinking, why did he call it 'Bacchanal with an Owl'? I don't see it. There's no out there. And, I'm thinking, oh, it's a subtle, like, Al Hirschfeld caricature/hidden-Nina thing. And, no. It's there, but interested viewers and listeners can go find that.
58:03	Russ Roberts: Are owls wise? We think of them as wise. You quote Hegel: 'The owl of Minerva begins its flight only at dusk.' There's many interpretations of that phrase. I had to just say it because it's never been uttered on this program, I don't think. But, we think of owls as--Minerva is the Roman goddess of wisdom, I think. Athena is the Greek. Are owls actually smart? You have a nice chapter on that. Talk about some of the things you learned there. Jennifer Ackerman: Yeah. So, owls are really very subtle, complicated, and intelligent in ways that we just never imagined. They're very different in their forms and styles of learning than ours, and different kinds of intelligence. But, they are certainly much smarter than we ever gave them credit for. And, I will say birds in general are a lot more intelligent than we imagined; and we thought small brains, small smarts. But, it turns out that in every bird brain, the brains are dense with neurons. And, that's really what is important in intelligence, and the communication between neurons. So, birds brains are very densely packed with neurons, and that's true for owls as well. So, they're definitely capable of far more intelligent behavior than we ever imagined. And, I like to give the example of this ornithologist I worked with, Rob Bierregaard. You ask him whether owls are smart, and he tells you a story about wild Barred Owls. So, he trains the owls to come to a whistle so that he can actually either put on a GPS [global positioning system] device or retrieve the device if he's already put it on. And, this is what he does. He puts a mouse in a grassy area and the owl comes down to catch it; and Rob whistles. And then, he puts out another mouse, whistles; another mouse, whistles. After three mice, the owls learn to come to that whistle. And they learn this in a one day, and it never takes longer than three sessions to get a bird completely trained. So, you know, that's a pretty remarkable measure of intelligence. I think Barred Owls in particular are very smart, very adaptable. But, I also think that our study of the wisdom and knowledge and intelligence of other animals is really in its infancy. We don't understand how other animals are smart. We can measure the ways that they're smart and that are similar to ours--you know, like crows' being able to solve physical problems. But, I think owls have forms of intelligence that we don't even know how to measure yet. So, I think we're really at the very beginning of understanding the depth of intelligence and the breadth of these birds. Russ Roberts: You write about the--this is an example of an owl learning. But, it was impressive or fascinating to me, how much of owl behavior--and it's probably, of course it's true of many birds and many animals--appears to be genetic. It is not learned from their parents. You can watch a cat teach a kitten how to play with a mouse, actually; and they'll paw at it. And, I don't know what they're teaching--it could just be they're having fun. It's like going to a football game for them. Talk about what owls seem to be genetically imprinted with. A lot of it's the hooting, right? Jennifer Ackerman: Yes. Vocalizations are genetic. So, unlike songbirds, for instance, which experience something called vocal learning--which is very rare in the animal world: it's really the same techniques that we use to learn to speak. So, it's listening, imitating, practicing. Those songbirds to their, learn their songs over time by imitating tutors. This is not true for owls. Owls really literally come out of the egg hooting. And, they hoot inside the egg, too. They are little chitters--actually, not hoots. This was one of the things that Karla Bloem discovered. Her great delight was that these birds start to vocalize in the egg before they hatch. And so, yeah. The vocalizations of owls are genetic. But they learn other things over time, clearly. I mean, there's Rob's story about the Barred Owl. But also, I was really interested to learn--and you might be too now with your connection with the Long-eared Owl--about the communal roosting of Long-eared Owls in Serbia. In these villages of Serbia. And, these owls will roost together over winter in the hundreds. So, you can look up into a tree in the village of Kikinda in Serbia and see maybe a dozen owls at a time. And, they believe that these communal roosts may actually be information-sharing centers. So, the owls are learning from each other about where the good food-eating spots are, what's dangerous and what's not. It's one of the things that we've really discovered that owls are very good at learning over time. So, some of their behavior is definitely genetic, hardwired, just as some of ours is, but some of it is also learned.
1:03:59	Russ Roberts: How did writing this book and the research change you? Jennifer Ackerman: Well, let's see. I mean, I think, like some of the young researchers, I'm really fascinated by the way that what owls have taught me about moving through the world in a quieter way. Listening more. And, I think I have just have a very deep appreciation for what we don't know about other creatures. Owls, they're so mysterious, we've learned so much about them, but there's so much that's still to be discovered. So, I feel like they grew my wonder in the natural world at large, and I think that was the greatest gift. Russ Roberts: My guest today has been Jennifer Ackerman. Jennifer, thanks for being part of EconTalk. Jennifer Ackerman: Thank you.

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Podcast Episode Highlights

0:37

Intro. [Recording date: August 29, 2024.]

Russ Roberts: Today is August 29th, 2024, and my guest is award-winning science writer and author, Jennifer Ackerman. Her latest book and the topic of today's conversation is What an Owl Knows: The New Science of the World's Most Enigmatic Birds. Jennifer, welcome to EconTalk.

Jennifer Ackerman: Thank you so much. It's a delight to be here.

0:58

Russ Roberts: What a fun book to write--and to read, by the way. Tell us about the process of how you came to spend the time you did with owls and what it was like.

Jennifer Ackerman: Yes. So, my first close encounter with an owl was some years ago. When my children were little, we put an owl box on the maple tree behind our house. And, it was very close, easy to see from our kitchen window, nothing roosted there for quite some time. And then, finally, an Eastern screech owl showed up. And this little owl would roost in the box with just its head showing--its little round head.

And, the girls were just fascinated. They were about seven and nine at the time. And, I would try to see this owl come and go, but it was so stealthy, I never saw it either enter the box or leave it. But, often in the morning my girls would come down for breakfast and out of the hole in this box would be hanging, say the wing of a blue jay or the tail of a mockingbird. And one time it was a whole mourning dove. And then, this thing would jerk, jerk, jerk right into the box and disappear.

And the girls were, like, 'Mom, what is this?' It was their first lesson--and mine, really--on a top of the line apex predator.

And, I was just fascinated by the idea that this little owl was coming and going in the night and coming up with this very large prey. When I opened the box finally after the owl had left, it was filled with feathers and all kinds of little bones and things.

So that was really my first introduction. And then, I thought--I've written about birds now for more than 10 years--and I got interested in the idea of really delving into a bird family. And, the group of owls, it's just so diverse. They're just so unique in the bird world. They're these very skilled night hunters. They have this eerie, quiet flight and these quite extraordinary senses. And also, we humans have really been obsessed with these birds for literally tens of thousands of years. So, I thought: Well, it would be just really interesting to find out what we actually know about owls. They're difficult to study and what have we learned?

Russ Roberts: And, as you alluded to there, they're different. They don't have one behavior, but they have many things in common. One is the predatory aspect of--you call them the 'wolves of the air.' Do anything--we'll talk in a minute about what they eat. Does anything eat them?

Jennifer Ackerman: Oh, yes. Especially when they're in egg form or when they're chicks: they're vulnerable to all kinds of predators, snakes, raccoons, skunks, other birds of prey. And, the little ones--the little owls--you know, they range in size from the elf owl, which is just about the size of a little pine cone--it's really a little nugget of a bird--all the way up to the Blakiston's Fish Owl, which is the biggest owl in the world, and that's about the size of a fire hydrant. And the bigger owls--Great Horned Owls, Eurasian Eagle Owls--those will eat smaller owls when they're adults, these little owls. So, the little owls are subject to predation from all kinds of birds of prey. The bigger owls, really not so much. When they get to be full size, they're pretty much king of the playground. Nobody goes after them.

4:48

Russ Roberts: One of the puzzles that I had reading your book, and we'll talk later--I've got some owls in my life right now near my office, which is really extraordinary. Those owls near my office sit motionless all day long, as far as I can tell. They may be playing cards when I happen to be working in my office. But when I go by their tree--and I tend to greet them; and there's anywhere from two to four birds in the tree on any one day--they're just motionless. They're sitting there inside the branches of a partially dead cypress.

So, it's a fantastically interesting tree. On the outside most of it is really, really thick. There's no way you could get in there. But there's a dead part. And the birds have found their way up into the branches. They're up quite high--a number of them, of the four. And, they sit there motionless.

And, as you point out, they're incredibly well-camouflaged. These are Long-eared Owls. They are really hard to see. When you point at them and show them people they can't see them. And, eventually you learn to recognize them.

NOT PUBLIC DOMAIN. Reprinted on EconTalk with permission: Long-eared Owl by Anthony VanSchoor; Cornell Lab of Ornithology | Macaulay Library — *Long-eared Owl by Anthony VanSchoor; Cornell Lab of Ornithology | Macaulay Library* Enlarge

But I'm curious why they're so camouflaged in the daytime. So, I don't think they have any predators here [Israel]. They may in other parts of their habitat. They're pretty big. They're, I don't know, a foot-plus tall, probably, at rest. So, I can't see them in the daytime when they're doing nothing. And, at night they're killing things--which, we'll talk about what they kill. But, why do they need to be camouflaged in the daytime? What are they worried about?

Jennifer Ackerman: Well, the truth is Long-eared Owls are prey for bigger birds of prey. So, they are being still to camouflage themselves.

And, I know what you're saying, because when I was in the field once in Montana, we were trying to trap a Long-eared Owl that was roosting in a gully, and my job was to keep my eyes on this owl while the team was setting up the mist net and getting ready to try to flush the owl and catch it in the net so they could band it and take blood samples and things.

I really failed at my job. I mean, every time I just turned my attention away for a second, I had trouble spotting this owl again. As you say, they almost look like a broken branch. They get very tall and thin. They have these plumicorns on their heads, which they make erect, and that makes them look even more vertical. Sometimes those plumicorns, they will sway in the wind like a branch would. Just so thoroughly camouflaged. But it is, again, as I say, because they can be targeted by bigger birds of prey.

Russ Roberts: So, let's stick with the Long-eared Owl for a minute because it's quite fascinating. The Long-eared Owl--which listeners can Google and viewers can Google and find anywhere you want [also see photo accompanying transcript--Econlib Ed.]--it looks like it has these little tufted ears rising up from the top its head. Those are the plumicorns, right?

Jennifer Ackerman: Correct.

Russ Roberts: They're not ears. It's a misnomer. They're not Long-eared. They're Long-plumicorned.

Jennifer Ackerman: Exactly.

Russ Roberts: Explain.

Jennifer Ackerman: Exactly. They look a lot like mammal ears, and that's true for Great Horned Owls, too, Eurasian eagle owls. Any of those owls with those plumicorns, you think, 'Oh, well, that's got to be their ears.' It's not. It's really largely about a camouflage. But, an owl's actual ears are really just holes in the sides of its head and they're covered with these specialized feathers that allow sound in. But it's just a hole, and you can look into that hole. So, yes: those Long-eared Owls are definitely misnamed. They're Long-plumicorned Owls.

8:59

Russ Roberts: And, one of the coolest things is that the ear openings, which--the things they hear through, which are not ears the way humans have them or other mammals--their ear openings are not symmetric. Explain why. At least on some owls. All or some? Most? I don't know.

Jennifer Ackerman: Some owls. So, particularly Great Gray Owls, Boreal Owls, Barn Owls. These are owls that hunt primarily by ear. And, they hunt at night.

And their ears are asymmetrically placed. One is higher than the other. And, that gives them the ability to really precisely locate the source of even the faintest noise in three-dimensional space.

So, to accurately locate its prey, the owl's brain actually compares the sounds that are arriving at each ear--first of all, how loud they are and also which ear detects them first. And, it's the difference in the time of arrival of sound waves between the two ears that helps the owl gauge the exact horizontal location of the sound. And then, it's the difference of loudness that helps it determine the sound's elevation. And, where that horizontal location and elevation intersect, that's where the owl actually directs its strike.

And, it does all of this sound processing within about 20 microseconds. So, it's all happening really, really fast.

Russ Roberts: And, some owls like the Snowy Owl can find a vole, which is a small rodent, underneath the snow because it can hear the rustling of the crystals of the snow, right?

Jennifer Ackerman: Yeah. So, this is actually the Great Gray Owl, and from a distance of 30 feet, this owl can detect the presence of a vole or a mouse or small rodent tunneling a foot and a half deep beneath the snow. So, this is really quite remarkable. And, what the owl does is that it will fly from its perch and hover over the sound, and then it just makes this dive that's incredibly accurate. The poor little vole has no idea what's coming. And, the owl inevitably just dives through the snow and comes up with its prey. It's really remarkable.

Russ Roberts: Have you seen that?

Jennifer Ackerman: I've not seen it. I've seen many videos of it, but I've never seen an owl actually go through the snow. Most of the field work that I've done was not in the winter.

Russ Roberts: But, I do want to mention: You did a lot of field work. We didn't get to talk about that. You spent a lot of time with the greatest experts in the world in their quest to understand this diurnal, mostly nocturnal, corpuscular bird that is a bit mysterious.

Jennifer Ackerman: Yeah. So, I was really lucky be with owl experts all over the world and spent time in the field with some of the best of them. And, we were in Montana, Europe, Brazil. These are wonderful researchers. These owl people are just crazy dedicated to their work, and it's really difficult work when you think about it. These owls are elusive. They often live in very remote locations. They're active at a time when access to field sites is difficult. So, these people are really super-dedicated.

And, their work is, I think, some of the most difficult bird research work in the world. It's very difficult to find these birds and to capture them. And so, it was really a thrill to be in the field with some of these people.

I also spent time with a group of community scientists. These are ordinary people, volunteers who give their time to owl research projects. And, there were a couple of them that were just really amazing to work with. There was a heart surgeon, and he devotes his time--now he's largely retired, but he was doing this while he was a surgeon as well--studying the Northern Pygmy Owl, the courtship and mating of these birds. And now he's one of the world's foremost experts on these little birds.

And, another one was Julie Kazmierczak[?sp.?] who is the coordinator of the emergency department in a major hospital in Richmond, Virginia. After a full day of work, at night, she goes out and bands Northern Saw-whet Owls. All night long sometimes, and then we'll go back to work in the morning. She's just phenomenal.

So, I got to spend time in the field with some of those people, too, and just saw some of the really amazing dedication.

Russ Roberts: Before we leave the vole, I do want to mention that one of my favorite poems is called "The Heart of the Backlog." It's by Robert Penn Warren. Unfortunately or not, it's not readily available online. If you subscribe to the New Yorker you can find it. I was going to read a part of it, but I realized, one, reading an excerpt doesn't do justice to this particular poem, and it's one of the scariest poems I've ever read. And it involves an owl taking a vole. It's really a spectacular poem, but I encourage poetry lovers to go find that poem.

14:24

Russ Roberts: Let's go back to the hearing and the sight. Until I read your book, I never realized that owls' eyes face forward. Of course I know that, but I never thought about it. And, it is part of the reason they see so well and can hunt at night. It's also part of the reason that human beings find them so fascinating because they look like us to some extent, unlike other birds.

Jennifer Ackerman: That's right. It's very unusual in the bird world to have forward-facing eyes. Most birds have eyes on their sides, and that gives them better peripheral vision to pick up the presence of predators. But owls, as you say, have these forward-facing eyes, and it really helps them in the kind of binocular vision that they need to zero in on moving prey.

Interesting that their eyes are actually locked in place. So, they have tubular eyes and they can't move their eyes. They can only move their heads. Yeah. So, yeah--in order to keep something in their field of view, they have to actually move their head. So, you stand near an owl and it can bob and circle its head trying to get a good look at you.

And, while it's not true that owls can turn their heads 360 degrees around, they can turn them about three quarters of the way--270 degrees--which is very impressive. And, it's about three times the twisting flexibility that we humans possess. So, really remarkable.

15:57

Russ Roberts: Let's talk about their eating habits, which--I warn parents listening with small children that sometimes topics have adult themes. This is not one of them, but it is a little bit gruesome.

They prefer to eat living versus dead, and they eat them at a go. They just take them in. So, talk about the range of things that owls eat and how they manage that. And, the strangest part, which you will explain for us, is: they don't eat all of it. So, go ahead.

Jennifer Ackerman: Yeah. It depends on the size of an owl. There are some owls that eat insects--the little ones--all the way up to, say, a powerful owl that will take a possum. And an Eurasian Eagle Owl will actually take a small Roe Deer. So, there's a huge range of prey. Many owls will eat small rodents: they'll eat mice foals, rats. They'll eat rabbits.

Russ Roberts: Lemmings.

Jennifer Ackerman: Lemmings. Yes. Snowy Owls, primarily 99% of their diet when they're breeding are these little rodents called lemmings.

And, they will also eat birds. And, as I said, some owls will eat other smaller owls.

And, often the smaller prey, they will eat whole. And, if you think about taking in, say, a mouse or a rabbit, it's going to have fur and bones and teeth, and those are things that the owl can't digest. So, the owl will eat its prey whole, and then the indigestible parts--all of these bits of fur and bone and teeth--the owl will compress in its stomach. And then, once it's all compressed in a tight little package called a pellet, the owl actually moves that pellet up through its esophagus and out of its mouth.

If you look at photographs of an owl ejecting a pellet, and it really is kind of gross. But, the fact is that these pellets are full of really interesting information about what an owl eats. And, in some schools, the pellets are dried and sanitized and kids get to dissect them and figure out what that particular owl was eating from the little bones, the little skulls, even the teeth.

Russ Roberts: Quite extraordinary.

Now, let's go back to my friends in the tree here. My four feathered friends. As I said, they don't move during the day. They just sit there, at least when I go by. I assume they're busy at night and they're looking for prey.

When they find that prey, do they eat it on the spot?

Sometimes they're taking it back to--the male is the primary hunter I think, when the female is nesting, at least? Or what's the word I want? Taking care of eggs. So, the male goes out, catches something--something he's going to bring back to the female or the chicks. But, let's say he's not doing that. Does he eat out on the road? Is he doing takeout? Does he bring it back at night and have some in the morning? And, the real question is: Should I see pellets at the base of that tree?

Jennifer Ackerman: Well, I would say in answer to your question: All of the above. Some of them are eating their prey on the spot. Some of them are taking them to a favorite roost. Oftentimes, one of the best ways of finding an owl is to look for pellets on the ground. And, owls do have favorite places to roost and to eat their prey, and then they will drop the pellets at the base of the tree. And so, then you can look up just as you did and spot your Long-eared Owls based on their pellets.

And, it depends on how hungry they are. And, sometimes they kind of stockpile prey. Like, Snowy Owls, when they have nests, will stockpile lemmings. And, Denver Holt--the researcher who has studied these Snowy Owls for 40 years--told me he found one nest where the owls had stockpiled 86 lemmings all piled up around the nest. And, the thing is: they know that these lemmings are not going to spoil because it's so cold in the Arctic so they're preserved, and then they get to feed the young, sort of lemming by lemming.

Russ Roberts: Oh, you never can tell: when you've got a good Netflix series and you have a longing for a lemming and you want to have one handy. You don't have to go search for it, miss the second season, or whatever.

They prefer, though, to eat them fresh. They don't like to stockpile, generally, right?

Jennifer Ackerman: No. That's right. In colder climates, some owls will cache their food, but most will just eat them fresh.

And, I once had--somebody asked me if I wanted to feed an Eastern Screech Owl, and I said, 'Sure.' And I kind of didn't know what I was in for, because what they gave me was a bag of very fresh, chopped up mouse parts. Very bloody, very fresh. So, I fed the owl little bits and pieces from this bag of carnage.

But, yeah. So they really--and it's one of the reasons that owls do not make good pets--and there are so many reasons--but they like their prey, their food fresh. So it's not an easy task to feed them if they're in captivity.

Russ Roberts: We'll come back to the pet thing, I hope, a little bit later.

22:15

Russ Roberts: But I wanted to ask about nests. Shockingly, most owls do not build nests. Correct? Explain what some of the--there's enormous variety, which you write about. Give us an idea of the range of ways that owls find homes.

Jennifer Ackerman: Yes. So, they don't build their own nests. None of the species do. They take over the structures that are built by other birds, other animals.

So, for instance, Long-eared Owls will take over the nests sometimes of ravens and magpies. The bigger owls, like Great Grey Owls, will commandeer old raven nests and hawk nests.

There's a really wonderful species called the Burrowing Owl, which nests underground in the burrows of prairie dogs, armadillos. You know, whatever will dig a burrow itself, these owls will then nest inside those burrows. And, there are a number of small owls that nest in the holes that are by woodpeckers in trees, and they create little cavities, and the birds will nest there.

Russ Roberts: They also nest in human creations, right?

Jennifer Ackerman: Yes. Certainly in nesting boxes. It's one of the ways that scientists can actually really control some of their studies. And, the variables in those studies is by building nest boxes; and the owls will take to those.

Russ Roberts: One of the things I loved that you write about--at surprising length; it's not long, but it's still surprising--is the virtue of a dead tree. You see a dead tree out in the world; and you think: You know, I was about to get rid of that. And, often they do: they make firewood or they do other things with it. But, as you point out, dead trees--and my neighbor owls here are a good example of that--this tree is not dead, but there's a big part of the tree that is dead, some of the inner branches. And they love it because they are perfectly camouflaged against that rather than the dark green foliage of the rest of the tree.

But, a lot of owls nest in those holes that woodpeckers find in dead trees where insects are, that the woodpeckers are trying to get out; or that just happen from weather and other things.

Jennifer Ackerman: Right. Yeah. And, one of the really, the favored nesting areas of Great Grey Owls--these big, beautiful majestic owls--is the top of a snag. A dead tree that's lost all of its branches, lost its top. And, it doesn't look like it's very comfortable. But the owls will nest on top of those dead snags. And, the snag often has a little bowl, and the owls will--yep. And, they'll nest there.

So, I always tell people, if you want to create owl habitat, if you have any kind of piece of land, or you just leave those snags, as long as they're not threatening a structure or something, they are really wonderful sources of food for so many different animals, and certainly nesting for owls.

25:46

Russ Roberts: Let's talk about the sounds that owls make. I've always thought I knew what a sound an owl makes, which is 'whoo, whoo.' Right? They say, 'whoo.' And, we call that hooting. Turns out there's a big range of noises. Talk about some of those noises and why they're important.

Jennifer Ackerman: Yeah. Well, as scientists have lately learned, a hoot is not just a hoot, either. Owls do hoot, but they have really elaborate vocal repertoires that are just teeming with meaning.

So, they have greeting hoots, they have emphatic hoots, they have territorial hoots. And, as you say, they don't just hoot: they also chitter and squawk and squeal. And all of these different calls communicate very different information.

First of all about the owl itself: they communicate information about the owl's sex, its size, its weight, its individual identity, and also its state of mind.

And then, all those territorial hoots, those are the vocalizations that we hear most often. And, you say it's the hoot of an owl. It's really one of the few bird calls that most people know. And, owls are very territorial, and the way that they protect their turf is through this hooting. So, it's far better than an actual physical battle, if you think about it. Because, if an owl gets a talon in the eye, it's kind of game over for that bird.

So, these birds, they defend their territory by hooting. And then they have all of these other vocalizations that are used in very specific contexts for very specific purposes.

And, we have just been exploring some of the range of these vocalizations in different species and learning also that owls have very distinctive voices, just as we do; and that they can recognize each other by voice alone. So, they use that to identify kin, communicate with mates, allies, rivals.

And, it turns out that researchers now can also identify owls by their unique territorial hoots. And, it turns out those are really consistent for each bird, and they're really sufficiently distinct from one another that you can actually fingerprint an owl--an individual owl--by its hoot.

And that means, really, two things. It means that scientists can actually monitor the populations more accurately--and that's a really important tool for conservation. And also, researchers can kind of observe by listening who is mating with whom and whether pairs are staying together. And so, it's providing a lot of information.

Russ Roberts: And you write about the technology that's being used now to analyze and using AI [Artificial Intelligence] in other ways to analyze the distinctiveness of those sounds.

There's also a lot of hooting and chirping and chittering from owl researchers who are either trying to attract owls to catch them, band them, keep track of them. But, there's also folks who live with, say, an owl that was damaged--now might be used for educational purposes--an owl that was injured. And, that owl communicates with--especially if that human keeper was with that owl when it was near its birth--it sees the human as its partner, friend, whatever, and talks to him a little bit. So, talk about that side of things.

Jennifer Ackerman: Yeah. So, people that keep captive owls--and they're often because these owls have been injured or because they're training them to be ambassador owls--owls that go out into community, schools, and to teach people about the nature of owls.

One of the people that keeps an owl that I learned a great deal from is a woman named Karla Bloem, and she runs the International Owl Center, which is in Houston, Minnesota--not Texas. A little town in Houston in Minnesota.

And, Karla adopted a Great Horned Owl named Alice. When Alice was, as you say, very little--and Alice now treats Karla as a mate, really, and hoots at her. And, in the beginning, Karla really didn't have a clue, like, how to hoot back to Alice. And, Alice got very upset with Karla, and at one point was on her perch and just smacked Karla. And, Karla was like, 'Well, I'm sorry. I don't know how I'm supposed to do this.' And it really launched this long study that Karla Bloem has done since, about the vocalizations of Great Horned Owls and what they actually mean. And also how to hoot back to her little partner, Alice.

And it has turned out, really--I think Karla found there were 15 separate vocalizations in Great Horned Owls, and now she can hoot properly back to Alice, which is a great advantage.

Russ Roberts: And, I think you're right, that Alice did not approve of Karla's boyfriends, but did approve ultimately of her husband. So, what happened there? What would go on?

Jennifer Ackerman: Yes. Well, as I said, owls are very territorial, and Karla would tell you they're also very good arbiters of character.

So, when Karla was dating, she would use Alice as a litmus test of whether the guy was okay or not. And, if that guy was not okay with Alice, she would dive-bomb him. And, it was not a pretty picture. But, when Hein, who is currently Karla's husband, came in the door, Alice was very accepting and actually favors Hein now over Karla. So, it was--

Russ Roberts: Karla okay with him?

Jennifer Ackerman: Yes. I think she's a little jealous, but it's all right. She's willing to share, I think.

32:19

Russ Roberts: So I should tell listeners that: when I connect with a guest on Zoom and I explain how the program works and what we're going to do. And I usually give them some warning: if I'm asked about some topic I explain you don't have to answer every question. If you don't, we can edit that out. It's not a gotcha show.

But I did not warn Jennifer that I was going to ask her to hoot for us.

So: You can decline if you want. But I'm sure you worked on some of your skills out in the field and either as doing some actual field work, calling to owls to try to get them to come by or just out of a natural desire to be part of the orchestra. Can you do some owl sounds for us?

Jennifer Ackerman: Okay. This is really not fair. Because this is not my forte. And, there are some people who are so good at it. Like, the people that work at the International Owl Center--they have to be so good. It's part of the job description that you have to be able to imitate hoots of different kinds of owls.

The only one that I can do even remotely well is--well, I can do two. Long-eared Owls are probably the easiest on the planet because it's just 'whoo whoo whoo whoo.' Great-Horned Owls are: 'whoo, whoo-whoo, whoo whoo.'

Russ Roberts: Nice. We don't get any chittering or chirping or any of the other more exotic noises.

Jennifer Ackerman: I can't do the other stuff. I wish I could.

And, I will say that a lot of people use either their own vocalizations--birdwatchers--their own vocalizations or what's called playback when they have a recording of an owl's hoot, to try to draw in the owls. And, the scientists do this and they do it in a very controlled way, and they do it for a very specific purpose.

But, I really discourage people from using this technique to draw in owls, because it--as I said, owls are very territorial. It uses their energy. They think there's a rival in the area, and they'll come in and they'll leave their nest and exposed. So, it's not a good idea in general to try to draw in an owl this way.

Russ Roberts: But, going back to my neighbors, the Long-eared Owls, I would love to hear them; and I have not. I assume they are quiet in the day. When do they--do they hoot? I mean, songbirds just sometimes seem to sing for at all kinds of times. Do they hoot at night? or do they hoot at dusk? If I wanted to hear them--I don't want to provoke them. But, if I wanted to hear them, when might I do that?

Jennifer Ackerman: Well, I would suggest either very early in the morning before dawn or around dusk. And, you will often hear an owl hooting just before it's about to go out on its hunt.

But it's not predictable. And, it depends on the species. And it depends on the situation. But, if I were you, I would perch somewhere near that tree before dawn, and I'll bet you'll hear that whoo-whoo-whoo of the Long-eared.

Russ Roberts: And, will I have a chance then also, I assume to either see--will they hunt all night long? Will those owls return at dawn or will they have often have caught something at 11:30 and now be back in the tree making their pellets and having a party?

Jennifer Ackerman: Yeah. Yeah. It's always really--you can't necessarily predict. Because it depends on how quickly they find their prey and again, how hungry they are, how long it has been since they've last eaten. And so, it's a little hard to predict there.

And, as I said, with this Eastern Screech Owl, that box was right outside my kitchen window. And I just never saw the owl come back to it. You know, and, I did watch. So, I think that was probably all times of night that little bird re-entered the box.

36:37

Russ Roberts: And, we won't go into it in detail, but these birds have incredible facility in flight. They're famous, many of them, for being either near silent--some think they're literally silent. Some are skeptical about that. But they're obviously dramatically quieter than many other birds. You can find many nice videos on YouTube--which one of your researchers said may be doctored for silence. So, keep a skeptical mind: but they're definitely quiet.

But, one of the things that strikes me about, again, my neighbors, is it looks like they can't get to where they are. They're sitting in this incredible thicket of dead branches and they're 20, 30 feet up the tree. I'm thinking, how did they get there? And when they leave, how did they get back? How do you fly in that ridiculous space? Are they climbing? What are they doing? Do you have any idea?

Jennifer Ackerman: Sometimes they're climbing, but I had the same experience that you did. When we finally captured this Long-eared Owl in that gully that I was telling you about, I actually got to hold the owl and release it. And, this gully was just dense. Choked with shrubs. And, that owl, when I released it, she just silently just wove her way through that very dense underbrush and out of the gully.

So, they are navigating these very dense vegetation--these trees--all the time. And, what's remarkable to me is, as you say, their flight is so quiet and that's largely because they have several features. They have a coating of velvet on their wings that quiet the sound of the feathers rustling against each other. And then, they also have what's called a comb across the front of the wing where the air meets the wing, and it breaks up any kind of turbulence that would make that swoosh sound that you hear with other kinds of birds in flight. And, the remarkable thing to me is that they can move amongst these branches and trees without damaging those feathers. So, it's really quite extraordinary that both the quietness of the flight and also the facility of their navigating these very dense vegetative environments.

Russ Roberts: The other part that seems strange is that--you can again watch on the web those gorgeous videos of owls taking flight. And, it's not a small matter. If they have room, they basically hunch up what we would say are their shoulders, and the wings start to bend and then they extend, and they're very long. And, there isn't room in this tree for them to fly with fully extended wings. So, are they able to fly at all with partially extended wings?

Jennifer Ackerman: Well, that is a really good question. I'm assuming so, but I don't know the answer to it. That is one of the other reasons that their flight is quiet--because their wings are so big in relation to their body size, so their flight is buoyant and slow. But, as you say, it's also kind of hard for them to get going.

I had the joy of seeing Flaco, the Eurasian Eagle Owl who lived in Central Park. He was roosting in--he's the one that escaped from the Central Park Zoo, and the New Yorkers fell in love with him. And, he was this really gorgeous Eurasian Eagle Owl, full size. Magnificent bird. And, every day at dusk, he would leave this oak tree and he would just do exactly what you say, which is just partially extend his wings. And then, once he was free of the tree, he would fully extend them. So, I'm assuming he was able to fly with that partial extension.

40:48

Russ Roberts: Part of the book is the mystery of these birds, which are by definition mostly active at night, so hard for us to observe. And, a good chunk of what you write about is the challenge of that research agenda of trying to understand them better. And, that often involves trapping them, banding them, taking a blood sample, trying to find out DNA [Deoxyribonucleic acid] [Deoxyribonucleic acid] of the birds to see whether species are related or not.

And, alongside that is this issue of: What's natural? That an owl runs into a car, or is hit by a car, is damaged. You mentioned at least one month--probably more hospitals where animal rescue takes place. And, do the folks in that field take about the ethics of that? To me, there's a certain--like, I don't have any love for voles, lemmings, mice, or rats, so--and I love owls. So I understand we want to save them and keep them alive and thriving. Emotionally, it's very powerful. But, trapping them in nets and subjecting them to procedures--not just, like, one. You write about people who've tried to find and band every owl in a particular area to do really quiet quality research. Which I get. Any--squeamish about that at all, either you or the folks in those situations?

Jennifer Ackerman: I will say that, to the person, they are all dedicated to minimizing the impact of their work on the wild owls. And so they work very, very hard to keep the time that they have these owls in captivity. Everything about it, they really try to make sure that it's not a traumatic experience for the owls.

And based on what I saw, these owls do fine. Once they're released, they have their band on. It doesn't seem to hamper their migration. They don't seem troubled by the tiny bit of blood that was taken. They seem to do just fine.

And, somebody like David Johnson, who runs the Global Owl Project--he's the one who wanted to study every single bird in his area. He studied those birds long-term; and they are doing just fine. They are reproducing like crazy. He started with eight pairs; now he has, I think, 560 birds at his site.

So, you know, I think the ethics of the study techniques: very, very well-developed. And, these people who are working with these birds are very highly trained. And, I think what they're learning is so important to preserving populations of these birds that it's really worth what I think is a very small risk that's taken to learn what we need to learn about how to preserve these birds' habitats. And, that's really the big one, because it's the biggest threat to owls right now. And, just understanding the populations, how big they are--we still don't know how many owls are out there. So, all of these research efforts are really contributing, I think, in a very important way to sustaining the populations of owls that we have on this planet.

Russ Roberts: Yeah. I'm not judging them. It just crossed my mind, reading about their efforts. And I think about the zeal with which we as humans try to have no footprint on the earth--which I think is silly, mostly, because we're part of the earth and we are part of nature. And, I understand that a truck hitting an owl is not natural--it doesn't seem natural. But not is it really that much different from a predator. It's a different kind of predator. I don't want to see their habitat disappear. I feel differently about that, obviously.

But, it's just kind of interesting that a lot of the folks that you spent time with see themselves as very much part of the natural world. And, write about it and speak about it. There are many beautiful moments in your book where people talk about what this work means to them emotionally, spiritually. And yet, they're doing something that is--in other settings we would say is somehow tampering. It's not that even that it would lead to bad outcomes for the owls. It just, like--it's just not--doesn't seem right. Again, I'm not judging them. I'm not saying that it's wrong. I just--I think there must be some tension in their feelings about this, I would think.

Jennifer Ackerman: Yes. And, I think that's especially true for the young researchers who are just getting into the field. Many of them have--their training has been to sit quietly and observe owls for many, many, many, many hours. And, that's a very different kind of experience than actually trapping an owl and handling it and banding it.

I do think that some of the young people do kind of struggle with that. But they understand the bigger mission. And their connection with these birds is, as you say, really quite extraordinary and profound and almost spiritual. And, I think they feel that they are learning something from these birds about how to be a good human. How to be subtle in the world and not stand out all the time--where there's so much pressure in society to stand out. And, these owls, they're so good at being quiet and discreet and subtle in the world. And, some of the young researchers I talked to said, 'Yeah, it's really taught me how to be in a different way.' And so, I think that's kind of marvelous.

Russ Roberts: One more thing on the quest for knowledge in this dimension. One of my favorite things that you write about is the use of dogs to understand owls. It seems like there wouldn't be any use, but there is.

Jennifer Ackerman: Yes. So, these are dogs that are trained to sniff out the pellets of rare owl species. And, these dogs can--the pellets actually do have an odor, which we can't really detect but the dogs can. And the dogs can be trained to detect one species of pellet over another.

So, these dogs are used by their trainers to explore very remote areas looking for these rare owls. And what the dogs do is they go out into these areas. They find the pellets. And then they wait for their owner/trainer to come; and the trainer looks up in the tree and there are the owls.

And they've done this in Tasmania with a Masked Owl, which is a very rare species, and then also the Northern Spotted Owl, they've used dogs to find.

And the idea of one species of animal helping to find another, it's just so beautiful. And these dogs are really remarkable. They're so well trained and they're so adept at their work. There were many times when I wished I'd had one with me to try to find the owls in the wilderness with these researchers. But, uh, yeah.

Russ Roberts: But the dogs don't eat the pellets. They just find them.

Jennifer Ackerman: They just lie down next to them. And, yeah.

And, they've been trained. There's a organization called Rogue Detective Team, and they look for rare species of all kinds, including mammals and insects. And, these dogs are trained to locate these rare species and then just leave them be and point their trainers in the direction of where these organisms are.

Russ Roberts: Yeah. Sorry. Go ahead.

Jennifer Ackerman: I just think it's an amazing--and it's not a common use, not a common way to find owls. Nut I think in certain circumstances it's very, very effective.

Russ Roberts: Interested listeners, if you missed the episode with Rowan Jacobsen on his book, Truffle Hound, which is a similar thing of training dogs to find truffles and ideally not eat them because they're very valuable--the pellets, different kind of value.

50:08

Russ Roberts: Let's talk about the Harry Potter effect and Hedwig, which--wouldn't have seen that one coming. Quite strange.

Jennifer Ackerman: Yeah. So, the Harry Potter effect, basically. it encouraged people to try to take owls themselves as pets. And, this was very common in the United Kingdom. And, unfortunately, as I said--

Russ Roberts: Because Harry Potter had this messenger owl, Hedwig, that --

Jennifer Ackerman: Yes. Will, they all had owls--of different kind. And Hedwig was Harry Potter's. A special Snowy Owl. And so, it was actually a male owl. Several owls played Hedwig in the movie.

But, in any case, the books and then the movies really encourage people to try to take these birds as pets. And, they are wild creatures. They do not belong in homes and for lots of reasons. They hoot all night. They shred things with their talons. They poop everywhere. They eat raw meat. It's just not a good plan.

And, as a consequence, after people found out how terrible these birds were as pets, there were all of these rehabilitation and refuge centers that had to be set up to take in the owls that people were then wanting to get rid of. And, it also fostered interest in pet owls in places like Indonesia and Southeast Asia where there are bird markets. People like to keep birds as pets. And, before the Harry Potter books came around that owls were just not part of the picture at all, but afterwards, they were very, very common in those markets.

So, I think it had a really, really negative effect. I think that's dwindling a little, but it's still present in some places in the world.

Russ Roberts: Well, at least negative on the pet side. I think it also romanticized owls in a really wonderful way. You write a lot in the book about superstitions and beliefs people have about owls as evil, bad luck, dangerous; and certainly the Harry Potter series, I think created a lot of love for owls. Maybe some of it misplaced for the pet project, but at least in general to care about them.

Jennifer Ackerman: Yes. I think that's right. I think it did generate some real interest and love for owls. I just wish it hadn't had this negative effect at the same time. But, as a species, we humans have been obsessed with owls for a very long time, so this is not a new thing. I think we love them and in some places we fear them, but they're present in our art and our culture and our stories through the generations, in every part of the world.

53:24

Russ Roberts: I don't think you wrote about this. I may have missed it. Besides the front-facing eyes, the nature of the owl's beak in most species gives it the look of having a nose. And, I wondered--and again, maybe you wrote about this, I don't remember--but the beak itself, in raptors, as far as I understood it, is used often to tear flesh from a carcass or a living creature. It's not used for the kill. And, the kills that we've been talking about are with the feet, the talons of the bird. The owl though, at least most of them have this very sharp beak-ish thing at the end of what looks like a nose. What's it used for?

Jennifer Ackerman: Yeah. It's not to kill prey. Owls also use their talons to kill their prey. Sometimes they'll use them to bite the back of the neck of prey. But, the main thing is they have really amazing feet and talons.

So, their feet have toes that can swivel into an X shape. So, they have four toes, and that ability to swivel these toes into the X shape allows them to hold onto prey. They have a special--it's like a ligament that locks the talons so that they can actually hold heavy prey without exerting any energy. And, I think that's one of the cool things.

And then, these talons are just razor sharp. You look at any of the researchers, the hands of the researchers who handle these birds--and they never handle them with gloves because they can't determine how much pressure they are exerting on the bird if they have gloves on--but their hands are just covered with talon gouges. They're very, very sharp. So, those little critters don't have a chance against those razor sharp talons. Killer talons.

Russ Roberts: But unlike, say, an eagle that would tear its food with that beak, doesn't the owl usually swallow it whole? Or does it sometimes break it up with the beak?

Jennifer Ackerman: It breaks it up with the beak. And also, if you think about an owl feeding it's young, it's tearing up those larger pieces of prey and making little chunks for the young to eat. Yeah. It's definitely using its beak to tear prey.

Russ Roberts: You mentioned in passing the cat-ness of owls. When I was teaching my granddaughter to recognize owls--just owls--she once saw a Long-eared Owl in a book and she decided it was a cat. She was about a year and a half old and meowed when she saw the picture of the owl. And I thought, 'Well, that's a bad mistake.' And then I looked at it and I thought, 'No, it looks a lot like a cat.' Which is interesting.

Jennifer Ackerman: Definitely. Especially the owls with those plumicorns.

In the book, I write about this wonderful researcher at the Metropolitan Museum of Art who got interested in finding all the owl images at the museum. And the reason she did was because she said her cat looks just like an owl. So it's the other way around. She thought, well, there's something so catty about owls and she loves her cat. So, she went in search of these images in the museum and she found, I think, close to 600 of them in all different media and through the ages. So, really, really wonderful stuff.

Russ Roberts: This is a G-rated [General-audience-rated] program, but there is a more adult-themed piece of your book. A page or so. Picasso had an owl; and some of his more adult drawings have owls in them, which is fascinating and cool.

But, there's a lot of art that owls there make a casual appearance in the background. I think it's "Bacchanal with Owl," and I'm looking at it. I went and looked it up online. I'm probably not the first reader of your book to think, 'Well, let's see what this looks like.' And, I open up the image and I'm thinking, why did he call it 'Bacchanal with an Owl'? I don't see it. There's no out there. And, I'm thinking, oh, it's a subtle, like, Al Hirschfeld caricature/hidden-Nina thing. And, no. It's there, but interested viewers and listeners can go find that.

58:03

Russ Roberts: Are owls wise? We think of them as wise. You quote Hegel: 'The owl of Minerva begins its flight only at dusk.' There's many interpretations of that phrase. I had to just say it because it's never been uttered on this program, I don't think. But, we think of owls as--Minerva is the Roman goddess of wisdom, I think. Athena is the Greek. Are owls actually smart? You have a nice chapter on that. Talk about some of the things you learned there.

Jennifer Ackerman: Yeah. So, owls are really very subtle, complicated, and intelligent in ways that we just never imagined. They're very different in their forms and styles of learning than ours, and different kinds of intelligence. But, they are certainly much smarter than we ever gave them credit for.

And, I will say birds in general are a lot more intelligent than we imagined; and we thought small brains, small smarts. But, it turns out that in every bird brain, the brains are dense with neurons. And, that's really what is important in intelligence, and the communication between neurons. So, birds brains are very densely packed with neurons, and that's true for owls as well. So, they're definitely capable of far more intelligent behavior than we ever imagined.

And, I like to give the example of this ornithologist I worked with, Rob Bierregaard. You ask him whether owls are smart, and he tells you a story about wild Barred Owls.

So, he trains the owls to come to a whistle so that he can actually either put on a GPS [global positioning system] device or retrieve the device if he's already put it on. And, this is what he does. He puts a mouse in a grassy area and the owl comes down to catch it; and Rob whistles. And then, he puts out another mouse, whistles; another mouse, whistles. After three mice, the owls learn to come to that whistle. And they learn this in a one day, and it never takes longer than three sessions to get a bird completely trained.

So, you know, that's a pretty remarkable measure of intelligence. I think Barred Owls in particular are very smart, very adaptable.

But, I also think that our study of the wisdom and knowledge and intelligence of other animals is really in its infancy. We don't understand how other animals are smart. We can measure the ways that they're smart and that are similar to ours--you know, like crows' being able to solve physical problems. But, I think owls have forms of intelligence that we don't even know how to measure yet. So, I think we're really at the very beginning of understanding the depth of intelligence and the breadth of these birds.

Russ Roberts: You write about the--this is an example of an owl learning. But, it was impressive or fascinating to me, how much of owl behavior--and it's probably, of course it's true of many birds and many animals--appears to be genetic. It is not learned from their parents. You can watch a cat teach a kitten how to play with a mouse, actually; and they'll paw at it. And, I don't know what they're teaching--it could just be they're having fun. It's like going to a football game for them. Talk about what owls seem to be genetically imprinted with. A lot of it's the hooting, right?

Jennifer Ackerman: Yes. Vocalizations are genetic. So, unlike songbirds, for instance, which experience something called vocal learning--which is very rare in the animal world: it's really the same techniques that we use to learn to speak. So, it's listening, imitating, practicing. Those songbirds to their, learn their songs over time by imitating tutors.

This is not true for owls. Owls really literally come out of the egg hooting. And, they hoot inside the egg, too. They are little chitters--actually, not hoots. This was one of the things that Karla Bloem discovered. Her great delight was that these birds start to vocalize in the egg before they hatch. And so, yeah. The vocalizations of owls are genetic.

But they learn other things over time, clearly. I mean, there's Rob's story about the Barred Owl.

But also, I was really interested to learn--and you might be too now with your connection with the Long-eared Owl--about the communal roosting of Long-eared Owls in Serbia. In these villages of Serbia. And, these owls will roost together over winter in the hundreds. So, you can look up into a tree in the village of Kikinda in Serbia and see maybe a dozen owls at a time.

And, they believe that these communal roosts may actually be information-sharing centers. So, the owls are learning from each other about where the good food-eating spots are, what's dangerous and what's not. It's one of the things that we've really discovered that owls are very good at learning over time.

So, some of their behavior is definitely genetic, hardwired, just as some of ours is, but some of it is also learned.

1:03:59

Russ Roberts: How did writing this book and the research change you?

Jennifer Ackerman: Well, let's see. I mean, I think, like some of the young researchers, I'm really fascinated by the way that what owls have taught me about moving through the world in a quieter way. Listening more.

And, I think I have just have a very deep appreciation for what we don't know about other creatures. Owls, they're so mysterious, we've learned so much about them, but there's so much that's still to be discovered. So, I feel like they grew my wonder in the natural world at large, and I think that was the greatest gift.

Russ Roberts: My guest today has been Jennifer Ackerman. Jennifer, thanks for being part of EconTalk.

Jennifer Ackerman: Thank you.

The Mysterious World of Owls (with Jennifer Ackerman)

Rowan Jacobsen on Truffle Hound

Wally Thurman on Bees, Beekeeping, and Coase

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The Mysterious World of Owls (with Jennifer Ackerman)

Rowan Jacobsen on Truffle Hound

Wally Thurman on Bees, Beekeeping, and Coase

LEAVE A COMMENT

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