Exploring Behavioral Ecology and Vocal Learning

Good morning, everybody. We will now begin. Welcome. Please create a distraction-free learning environment for yourself and for the people around you. Something's making my mic run. Welcome to ecology. What are we at? Lecture number five or so? Here we go. Six. There it is right there. Lecture six, behavioral ecology part one. And today we are going to break from the textbook for the only time in the semester because we have now reached the best part of ecology, the topic of behavioral ecology. Why is it the best? Because it happens to be the branch of ecology where I conduct my research and we're going to talk about it. So what I want to do is do a little introductory to the topic of behavioral ecology that is going to carry us through the whole week because on Thursday we will deal with the textbook chapter on this topic. But today we will divert from the textbook and talk about the behavioral ecology work that we do in my lab on vocal learning in wild birds. That's our goal for the day. Let's do our logistic break now instead of in the middle. So Lab 3 is this week. I posted it early this morning on the website under the lab section. There is a Word version and a PDF version. They're identical to each other. We also posted the independent project. the big thing that we're working towards, that all of the other lab activities lead towards. So you'll see two things there that you're going to want to read. The lab three, which contains two assignments, more on that in a minute, plus the overall big picture view of what we're doing with the independent project. And I'd like you to find both of those. I've only posted that one as a PDF because you don't have to fill out any information in there. But it contains the overall... What is it, 20% of your final grade arising from that independent project? It also includes the marking scheme of how the GAs will be evaluating you. And of course, a clever student like you knows that before you hand something in, you want to see what the GAs are doing to evaluate you. You'll find all of that. Don't forget, Laboratory Assignment 2 is due this week by email before your lab starts. We had a GA meeting this morning, and some GAs said we asked them to hand it in in paper, others by... email. We decided let's be consistent and let's just always go email. They'll explain more this week, but everything can be submitted by email. It means that someone who doesn't have a printer is not up the creek. So you can submit everything from here on by email. Your GAs will explain more this week. If you're unwell, please do not come to class. Please listen online and please don't come to lab so you don't make others sick, but you will need to... email Candy and your GA to make sure they know and that email should be received before the lab begins, before the time that the assignment was due. Can't get the assignment done because you're really sick? Get well soon and then hand it in. We won't penalize you if you're sick. Take the time you need and then include it, getting it to them as soon as you're back in good health. So this week's lab, lab three, has two assignments, assignment three and assignment four, that arise. Remember on page three of our course outline, you've got this list of what happens each week. Here we are, September 26th and 27th, week three. In the light green at the bottom, you'll see assignments three and four are given to the students. And assignment three is due on October the 1st, which is a weird day. It's a Tuesday. Whoops, I forgot a space right there. And then assignment four is due after the reading week. This is all clear if you read this, but this is one week where the single document includes two assignments, assignment three and assignment four. Your GAs will explain more about that. Here's a screen grab of the lab section where we've got lab three in PDF format and Word format and the ecology independent project. Any questions before we move forward? Yes, your name? Adina? I love this question. Can I please talk about the midterm, which occurs a week from Thursday? I've got slides ready for Thursday and Tuesday that I will share example questions with you from the lab, from your midterm, and I will share strategies about how to succeed on a Dan Menel-ridden midterm. So that's coming up. on Thursday and Tuesday ahead of the midterm exam which will take place right here or in SAS a week from Thursday. I'm gonna mute myself for a second and figure out why the mic's acting crazy. Bear with me for a moment. Do you have any other questions while I'm trying to fix this? About labs? About the midterm? Anything? Yes, Donny. Good question, Donnie. You have to partner with people within your lab section, as the GAs will explain. A few of our labs have odd numbers of people, so the GAs will allow one group of three, and they'll explain all the details of that in lab this week. Oh, Manil, I hate writing labs with other people. Sorry. In real life, like all the work I'm about to describe for you that we do in my lab is all done as a team. And so scientific teamwork is a really important skill that the GAs and I want to teach you, may force upon you in this independent project. So you can be ready for that this week. You could be planning who you want to work with. We'll leave that up to you. If you don't know anybody, we'll pair you up when you come into the lab this week. I think I'll leave the rest of it, Donnie, and everybody else for the GAs. They're in charge and they'll explain everything when they see you. Right. Fingers crossed that this is better. I'll just stand here if I need to. Seems good so far. OK. Let me orient you in this course. What's ecology? That's a good question. Ecology has many definitions, but a good one is the study of the relationships between organisms and their environments. We started in our first lecture talking about symbiotes and relationships. and the fundamental unit of ecology being the ecosystem. We then talked about both biotic and abiotic environmental influences and how ecologists spend their time trying to track the inner workings of biotic and abiotic environmental influences. That included a lecture on ecological energetics and how autotrophs capture energy from the sun and form a key part of the trophic pyramids of energy transfer. through food chains and food webs. We talked about nutrient cycling and how all of the nutrients that are necessary for life move through different forms and different compartments during ecological processes. Most recently we talked about population ecology. What is a population? What features define the growth of population and the factors such as pecundity or survival that influence population factors. Going into the midterm, we have three more lectures. Today and Thursday, we're going to talk about behavioral ecology. Today is an incursion from the textbook as we talk about my behavioral ecological work. Thursday is focusing back on the chapter six of the textbook that deals with behavioral ecology from a more general perspective. Finally, a week from today is our last topic of stuff that will be on next Thursday's first term test. We will talk about physiological ecology and how autotrophs and heterotrophs use physiological systems in order to live in the world. Good? So there's our math. That's everything leading up to term test club. The behavioral ecology is the study of the behavior of organisms with a special reference to the adaptive significance of those behaviors. Why on earth? When an ungulate carry massive antlers that could weigh as much as its entire head and impede it from its ability to move around, why would it do so? Because there is some adaptive significant value to that, some value that serves and offsets the cost of that trade, bringing a benefit to that trade. And you may well know that in the context of ungulates, antlers are often having an adaptive benefit of being useful weapons. during battles with other male ungulates in competition over resources. Behavioral ecologists spend a lot of time thinking about what kinds of activities and behaviors do organisms engage in in the natural world that give rise to their survival or to their death. Was the lizard well camouflaged or not when it was depredated by a snake, for example? Behavioral ecologists spend a lot of time thinking about how do organisms defend resources. All of us need access to the right source of food, whether for an autotroph trying to gain access to the sunlight, or an emertroph trying to compete to gain the most nutritious and valuable food or water that is necessary for our growth. And so a lot of behavioral ecology is defined by figuring out the ways that one species or another engages in different forms of competition. I highlighted the way that plants are almost behaving, and many biologists do study plants, thinking about two plants in a race for their food, being given sunlight, and trying to gain a competitive advantage by reaching that sunlight first, and help competing in other organisms, competing for the same resource. Or this rhinoceros beetle who's trying to compete for a little area where it can display and try to attract females who don't have these rhinoceros-like projections off their carapace. And they will do that just like a deer would, by using their armaments in order to battle with other members of the same species. The behavioral ecologists spent a lot of time thinking about mate attraction. How do organisms attract their mate with... big antlers, or with big sounds, or with big smells, in the case of orc animals that communicate through pheromones. Behavioral ecologists spend time thinking about which behaviors are important for reproduction. Some of the most highly evolved behaviors in the animal kingdom, elaborate courtship displays of wandering albatross that might meet a courtship period that lasts much longer than when you met your romantic partner. Are they from spending... weeks to months deciding if they like another animal by engaging in these elaborate courtship displays in order to choose which partner to reproduce with. After animals have found resources and attracted mates, behavioral ecologists spend time thinking about how do parents interact with their offspring. We'll return to the mysterious case of a male lion and a female lion, and seemingly mistaken behaviors that males often exhibit engaging in infanticide. But it is a behavior that ultimately we strive to understand its adaptive significance by figuring out why would a male lion ever kill a cub? And many of us know the answer from watching Disney movies, of course. Behavioral Ecologists will spend time thinking about what's the difference between last spring where there was one bird that saw that window while I was studying for final exams, singing a song all by himself, and this morning I saw that same species of bird in a flock of a thousand flying over South Windsor and LaSalle. What are the different factors in the environment that give rise to an animal to move out into the world as a solitary individual versus gathering together in groups? These are the questions of behavioral ecology. And they're the kind of questions I find most exciting, that I got really tuned into when I was doing graduate studies, like your GA's, a lot of your GA's are behavioral ecologists as well. So I've talked about how this course is a sampler of all of the different branches, or many of the different branches of ecology, at least the longest standing branches of ecology, and this week we're focused on behavioral ecology. So... Like most of your professors, I spend 40% of my working life teaching, and I love it. But I think it's imperative for you to know, as undergraduate students here at the university, that like any good university, any PhD-granting university, most of us also have another 40% of our working life that is devoted to research. So the work I'm going to describe for you today is the work that I spend a lot of time doing. 40% research, 40% teaching, and then 20% service defines the life of a university professor. Service is things like serving on committees, serving on a group I work with as the Associate Dean of Graduate Studies and Research to help our graduate programs and the research programs with my colleagues to succeed. So that is the ratio of what professors do. And I want you, as second-year undergraduate students, to recognize that profs have this other life, too, where we communicate with other colleges from around the globe, in my case, behavioral colleges, who are working on different topics at different universities. And this talk that I'd like to give to you today is a talk that I get traveled around the world to deliver sometimes. I gave this talk in France and the United States over the course of the summer at big conferences. And it is important. part of my life just as it is for any of your professors to do research, establish their own niche of research that they're working on, and gather together with other experts across the globe to share in those ideas. So, we have lots of work in our lab, but today I've chosen to focus on one project called Vocal Learning in Wild Birds, the dynamics of vocal learning in nature. And if my slides look a little weird, it's because these are the slides I use to go out and present to other people and advertise my website and my Twitter handle. You can follow me if you want. I won't follow you unless you ask me to follow you. Well, I don't make people hear you're on Twitter anyway, but if you are and you want me to follow you, let me know. But sometimes that feels invasive. I don't want to. I force myself on you. Anyway, here we go. Okay. Before I get to the research talk on local learning in wild birds, let me tell you about the framework of the work that we do in our lab. In our lab, we study the behavioral ecology of animal communication. We do a lot of reporting of wild animals and use the sounds that they produce as a window into their minds to try and understand what does an animal want in a reproductive partner, when is it important to defend resources. We can find out a lot of answers to the big picture of behavioral ecology. questions by studying patterns of animal communication and really get an adaptive significance of the different behaviors. That is the heart of behavioral ecology, figuring out why certain behaviors are beneficial or costly to an animal. And along the way, we use the tools of recording and the tools and the ideas of behavioral ecology to try and protect... animals whose numbers may be in trouble. And so it's not the work I'll focus on today, but some of the work that will pop up a little bit later in this course is to do with animal conservation as well. We find these themes in our lab and today's talk is about the first theme. I've sort of five different talks that I give at different places over time, but today I'm going to focus on maybe my favorite one on vocal learning and cultural evolution in wild birds. If you're interested, we also study communication networks. What happens when we recognize the fact that a lot of animals live in earshot of conspecific animals and exchange information? They're not just one male singing to attract one female, but there's lots of listening females and lots of other singing males out there. And so while animals can be visualized as a network, networks provide us with some mathematical tools for understanding their behavior. We study female signals. When you wake up... in the spring and a bird singing loudly outside your window, you're hearing a male. Here in the temperate zone, only males produce those long, musical sounds that we call birdsong. Females are nearby, but they're largely silent, producing just quiet little notes that both sexes produce. That's common in the temperate zone, but in the tropics it's quite different. In the tropics there are many species where both males and females sing, and by working in Costa Rica, Colombia, and Mexico, We try to understand why those behaviors evolve in the tropics, and why don't they evolve in the temperate zone. We study diverse social signals. Myself and my partner, my life partner, my research partner, Dr. Stephanie Busset, who you might take up your courses with after ecology. For example, one time we found these brown toads in Costa Rica that turned bright lemon yellow for one day of the year, like a chameleon. bugger toads, an undescribed phenomenon and we found that they're doing that in order to gain a reproductive advantage. It's a behavioral ecology question, finding a pattern of a behavior in a wild animal and asking about its adaptive significance. Finally, we do some conservation bioregistic studies like we have microphones all around the Great Lakes, pointing up at the night sky in order to sample warblers and other birds as they fly by in migration. as a tool for surveying how their populations change over time. Those are five of the research themes in my lab, and today I'm going to tell you about the first of them. Some of the broad techniques that we use in our lab include field studies. All of the work that I do involves going out to study animals in their natural environment. In my opinion, that's a little more interesting than studying animals in the lab, and it's also a lot more fun to be able to go out and spend time outdoors with animals. We do a lot of recording. That can be with, well, I'll show you some pictures. You should always have a typo picture where I've turned up your microphone, a parabolic reflector, so I could record you, but I wouldn't pick you up very well. It gives me a very directional column of sound. This kind of recorder here is an omnidirectional recorder. I could plonk this right here, and it would record the entire room in an omnidirectional. We do a lot of sound playback. When you're interested in the evolution, the behavioral ecology, rather, of acoustic signals, you can use a loudspeaker to simulate a person. or a frog, or a monkey, or a whale, and then figure out how other animals react to it. And finally, we've helped to find a bunch of radio telemetry approaches, where we catch a bird, put a little radio tag on it with a backpack kind of thing that straps around his legs, let it go, and then we can track that animal in order to figure out where it migrates to, or how far the young travels from its nest until it ultimately eats. Alright, with that background, we dive into this topic about vocal learning in wild birds. So here we've got six different groups of animals. Songbirds, hummingbirds, and parrots. Cetaceans, which is a scientific name for whales and dolphins. Bats and hounds. Now these six groups of animals share in common a behavior that no other animal in the animal kingdom exhibits. And that is the behavior of vocal learning. where young animals have to be exposed to adult sounds during a critical window early in the animal's life if the animal is ever going to produce normal adult sounds itself. It's true for you, and it's true for the Savannah sparrows that I'm going to tell you about today. It's not true for your cat or your dog. If you isolate a cat or a dog at birth from its parents so it never hears a meow or a woof, It will still grow up to produce normal meows and woos. There are sounds like most animals in the animal kingdom are innate. They just have to grow up and the genetic programming to produce those sounds is contained in their genes. But that's not true for these six and only these six groups of animals. Quite interesting in the case of humans, no other primate has this behavior but we do. If you are isolated at birth or if you are born deaf, You know, a deaf person, their voice sounds slightly different. And that's because they were not exposed to typical adult sounds in order to hear them early in their life, and so they don't produce the typical sounds as adults. It's quite a rare behavior, but it's an exciting behavior. And by studying birds, we can come to understand how this behavior works in a way that we couldn't always do with humans. So by studying vocal learning, the April College has been working on... The mechanics of how this works, the adaptive significance of different behaviors, for many, many decades. And we've developed a good model of how vocal learning works. Most animals, including you and me and songbirds, have a sensitive phase that's restricted to a narrow window early in your life. And you have to hear sounds during that critical window in order to produce them as adults. Then many, but not all, animals undergo a silent period. Humans don't, but birds do. This is usually a copy with migration sound, or like a chickadee that doesn't migrate, just hunkering down and surviving the winter. Then comes a pattern we all have of the sensory motor phase, which is a fancy word for babies babbling, producing lousy copies of adult goo-goo-ga-ga kind of stuff, that then start to get more gooey and gah-y as time goes forward. The sensory motor phase is producing poor copies of adult sounds that get better with practice. And then one day, crystallization occurs. At one day, and it happens very quickly, and my kids, you know, over the course of weeks, they went from goo-goo-ga-ga to real speech. That is called crystallization. It is the point at which neural activity becomes more fixed, neural connections become rigid, and they stay that way for the rest of your life. Like, if you're trying to learn a second language at your age, you can still kind of do it, but not as well as, like, my 10-and 11-year-old can. Our brains become fixed at a certain point shortly after puberty in humans, shortly around the age of eight months in birds, where they are much harder to learn new sounds, or learn them at least with a good accent. So this is the process of vocal learning. That's how it works. We have studied this behavior in laboratory-reared animals for decades and decades. Like this one. You know this species? Maybe someone has one of these at home yet. It's the zebra finch, which is like the white rat of the behavioral ecology of birds on the world, because you can hear that in captivity. We've been studying it for a long time. It allows us to get at that model of how global learning works. And we can manipulate them in a way that would be pretty unethical for me to manipulate you, to remove you from your parents and play you different sounds at different stages of your life. You couldn't do that. But we can, at least we historically consider that to be an ethical approach with wild birds. But what about when you go outside of the lab? What if you look at animals in their natural environment, where they're not just hearing certain things, where they're migrating, interacting with very broad groups of other individuals, and there's environmental noise, anthropogenic noise, or naturally occurring noise? Do all of our models of vocal learning hold up in the wild? There are certainly lines of evidence that they do. Here's one good line of evidence. It's correlation evidence. Someone went up and down the coast from British Columbia to Washington State to Oregon, California is right down at the bottom there, recording this species called the white-crowned sparrow, the name of the species is important, but as they went, they found all the animals in a particular population sounded similar. And then they crossed a line and they all sounded a little different. And they all sounded a little different the further south they met. This is called a dialect and we have it in humans too, right? That someone from Texas sounds different from, uh, I'm not going to do a new land accent, but humans have little dialects too. And just like in birds, this is consistent with the idea of learning sound where you were born, dispersing on average some short distance and ending up singing sound. Producing speech in an area near where you learn it is consistent with the idea of vocal, although it's not an experimental test of it. There's a typical White Crown Stereo song, it's the top one. I've never shown you these weird squiggles before, have I? This is called a sound spectrogram. A sound spectrogram is the way of visualizing sound, it's like a piece of music. So we've got that beep and in a way of visualizing sounds so that something that occurs really quick can be tracked very carefully in order to figure out what are the differences. And you can see the differences are quite pronounced in California. So the objective of the work that I'm going to describe for you today was to use an experimental approach to study vocal learning, but for the first time to do this outside of the confines of a laboratory. To study in wild birds where all of the noisiness of nature, the interactions with competing mates, rival individuals, and migration comes to bear, and study the process of vocal learning in a wild bird. That's the objective, and the study animal is this amazing animal, the savannah sparrow. The savannah sparrow is a, some people might call it an LBJ, a little brown-jogging. It's not going to win prizes for the best looking bird. You can see one in the grasslands of Ojibwe for like another week before they fly south, but they'll be back in the spring. They're a typical sparrow, short seed-crushing beak, mostly brown, a little bit of yellow above their eyes. Nothing fancy until they open that beak and sing this great song. So here again is the spectrogram, frequency on the y-axis, time on the x-axis. Every male Savannah sparrow sings one song, and it sounds something like this. Kind of insect-like, a little bit thin and buzzy, high-pitched. But when you visualize it as a sound spectrogram, you can see there is a lot of complex information in there. These high-pitched introductory notes, this middle section, which is highly variable between individuals, the buzzy grasshopper section, and this terminal trill. They're singing this song a lot throughout their reading period. Our study site is in Eastern Canada. Instead of just going to Ojibwe, I take my family and my students across the country out into the middle of the Bay of Fundy there. I'll explain why in a moment. In the middle of the Bay of Fundy is this island called Kent Island, where there is the Bowdoin Scientific Station in New Brunswick. It's an American college, Bowdoin College, that runs this station, but they let us work there, thankfully, because this is an amazing island. that is covered with savannah sparrows. Here's a view from the highest hill on the island. It's a small island, it's like the height of the campus. It's about three kilometers north to south and you can see it's pretty thin east to west and there's a couple of other little islands. You remember the Bay of Fongyin should go. They have the highest tides in the world, but high tide just ruins other water and low tide is fully exposed. About 30 feet between high tide and low tide. So these other islands are continuous with their main island at low tide, and they become separate islands. So this is the grassy area where the Savannah Sparrows live. There's lots of other cool animals on this island, like herring gulls, much bigger than the gulls we see in town here, which are ring-billed gulls. These are massive gulls. They're the bad guys in Puffin Rock. Are you the age that you might have grown up watching Puffin Rock as kids? Or maybe you're that too old, I don't know. Anyway, very nasty creatures. They'll dive on you and try and be... crack her head open if you get too close to their nest. But there's 10,000 of them on this island. There's also eider ducks. Have you ever heard of eider down? Eider down is a prized substance to make really expensive like red coats, right? It is a very good insulating down because these animals live in zero or sub-zero waters in the ocean. And they all smelt extinct from North America except for this island. Kent Island, where the eider ducks held on and were protected by philanthropists from the United States. He said, no hunting eiders on this island. And from that, since the 1930s, this species has rebounded. There's a bunch of little albatrosses, about 4,000 of them, that live on this tiny island where there are no mammals, except for us. So there's nothing to eat them. They live in burrows underground, and you only see them at night. Very cool animals. And best of all is this amazing little bird, the savannah sparrow. There are about 300 breeding pairs of Savannah sparrows. It goes up and down each year. You know about carrying capacity in a wild population. It fluctuates around a long-term mean. At our long-term mean, we need 300 pairs or 600 or so individuals. Every year when we get to Kent Island we capture every bird we can in the middle of the island. And we do so with these nets that are called mist nets. They're called mist nets because you can't see them very well. They just create a mist-like appearance. A bird doesn't see them. You can see the nets all billowing up in the wind there, but here it's starting to be spread out by an undergraduate researcher and my collaborator here on the poles. It stretches out kind of like if you stacked Four volleyball nets, or badminton nets, atop each other, but with very, very thin threads. And a bird flies into that, and ends up caught in a little pocket of the net, and then we race up and get the animal out, making sure it doesn't injure itself. We are very good at handling birds. And then once we have the bird in the hand, we process it as quickly as we can, usually two to five minutes, so we have the bird out of the net. And we do a couple of things that any behavioral ecologist or ornithologist We do when they have a bird in the hand. We collect feather samples by plucking one of its tail feathers, a couple of its back feathers. We can use those in genetic analyses. We can use those with some chemical approaches. We can figure out where it overwintered last year by looking at stable isotopes and questions like that. We can take a little blood sample, just a pinprick of blood that we collect with a capillary tube. That allows us to figure out which animals are related to each other and to the order to address questions about who can breed. or about paternity and questions like that. And then most importantly, we give every bird that we've captured a unique identity. We're licensed banders by the Canadian Wildlife Service and anytime you band a bird, you have to put a little numbered band from the Canadian Wildlife Service, the silver band here. If you've ever spent time at Holiday Beach, has anyone gone to Holiday Beach? They have a great bird banding program. They're always looking for people interested in learning these skills. If you want to get introduced, reach out to me. They just, they're a migration monitoring station, so they're just putting number bands on birds, hoping that someone, somewhere else halfway around the world might catch that bird and we'll figure out their migration route. But we're, in addition to those number bands, we're putting little colored bracelets on their legs. Like this guy's got a black on his upper left leg, a red on his lower left leg, and orange on his upper right leg. And so we could just... A breedie, that is B-R-O, the first letters of each color, black, red, orange, or instead of having to say B-R-O or black, red, orange, we'll just call them bro. See, so then we'll come back, oh, did you see if bro had attracted a mate yet this year? No, but I saw that leader, white, blue, yellow, red, was starting to affiliate with owl, orange, white, light blue, down past the tall pine tree. This becomes a way that we can lift up our monopters and go with orange. white light blue that's that particular bird we can keep a record of it and we know when he was born where he was captured who he made it in last year when he arrived and left for migration so this is a way of attracting each individual and because i can't tell the look of one samantha sparrow from the next but i can look at the bands on their legs and use that as an individual like them so this population has been studied in this way since the 1960s It's one of North America's longest-running field-based studies of the behavioral ecology of a wild micro-48 animal, where the animals have been captured and individually banded. Here we've got yellow, red, white, so Y-R-W-U-R-M. That one doesn't really have any saccharin. Don't tell them about that yet. Okay, so we've decided to populate for a long time, and the reason that it's worthwhile to go out in the middle of the ocean and take this long journey into eastern Canada is that this population has unusually high natal cycles. phylopatry, which is a fancy way of saying that birds who are born here return here after migration. And that's quite rare in most animals, including mammals and local birds. After they leave the area where they're born, they disperse away. That might involve migration to the south and coming back to a different population, or it might just be moving away from where you're born. And that's true of animals and birds and many other species. Why do so many animals have this post-juvenile period of dispersing away from the area where they're born? Put your hand up for me. Good. One person, two. Good. You were first. To mix genetics with other populations to avoid any breeding. Paige, is that it? Do you agree? You had your hand? Are you in agreement? Good. You're right, so thank you. You don't want to meet with your siblings or your parents because usually the offspring are not viable, with some very rare exceptions that you learn about in classes like evolution or genetics. And so there's strong pressure for animals to avoid returning to where they were born. For some reason that we don't yet know and we're studying it, the animals in this population don't do that. Maybe it's because they're born on this little island in the middle of the ocean and they have this particular mark of a place they want to fly back to. But whatever the reason, they return to this island over and over again. And if you care about vocal learning, this presents a special opportunity. I can record every sound these wild birds learn. and then have a chance that they will return from migration and I'll be able to record them and hear what they sound like as adults. Or maybe I can even use loudspeakers to manipulate the sounds that they hear in their youth and have a chance that I'll be able to find them given this high rate of natal cycle. So the annual cycle of these birds, these birds, like so many temperate animals, are born after the spring period. Females that arrived from migration got the nutrients they need mostly through caterpillars so that they can start the late eggs. Those eggs hatch in June, and the life of those Spanish Barrowbegians. They remain on the breeding area, whether it's our island or here or wherever, for about three months. Rowing, getting their feathers longer, learning stuff like how to fly and how to forage. And then they take off in mid-September, flying to the over-October winter in the southern United States. We know from those little bats. exactly which farms they're going to in Tennessee, North and South Carolina, Florida, Mississippi is where some of our animals are living. Spring starts to arrive and males arrive first. Males arrive first from migration in mid-April. Females arrive two or three weeks later. They mate and the process begins anew. That's the annual cycle. They live two and a half years on average. The longest lived animal ever was seven years. You know their survivorship curve, tech G's survivorship curve? Okay. Song, the thing I'm really interested in from a behavioral ecology perspective, trying to understand the adaptive significance of vocal learning and singing behavior, is common when these animals are on their breeding territories, but they don't sing when they're in the winter. In the overwintering areas, when we find them in the southern United States, they are not singing. This is stuff that is only found during the breeding season. One of my master students, a French woman named Ines Morin, and I recorded many birds over a very long period and we found that as soon as males arrived from migration they sing a lot. Here's 4 a.m, 6 a.m, 8 a.m, up until 10 o'clock at night. They sing the most at dawn and then it goes to lower levels over the course of the day. Most birds do this. You know this, right? In the springtime you get that huge burst of birdsong early in the day called the dawn chorus. When females arrive from migration, they change their singing behavior. They sing the most in the evening. Any guesses why they would make this change during a period of female arrival? Yes, I forgot your name. You're my colleague. Yeah, why would it be useful to sing at night? In fact, it's because the females are arriving, and like most little birds, they fly at night. So I think they're singing at dusk, you're right, to attract the mate, to sort of be like, hey, any females up there? I'm down here as a reproductive male. And I think that's why they're singing the most in the evenings, to attract the mate. Then, when they're really busy, they pair up, they reproduce. When they're feeding the young, feeding the nestlings, or after the nestlings can start to fly, they feed all around and feed them some more. they sing at lower levels, and then when those fledglings are present, their song is at its lowest level, and then it will disappear in September until the next year when it's patterned along. So that was one of our first projects, to figure out when they sing. We find they sing at dawn or dusk and throughout the breeding season. A lot of variation in when they're exhibiting this behavior. But to return to my primary objective, using experimental approach to study song learning in wild birds, to address that objective, I had this idea. I'm using a loudspeaker to simulate a tutor on the island broadcasting songs that I could use in an experimental context to figure out whether young Savannah sparrows are listening to sounds they hear in their youth and then later producing them as adults given the high rates of natal site phytopathy in this population. There were no good speakers I could find, like the little Bose or Sonos or whatever. Those only last a very brief period. They're not very fancy. So I worked with engineers at an electronics company to design speakers that were weatherproof. I could leave them out for three months at a time. They were programmable, so if I had multiple speakers, I could make them engage in interactions between different tutors or have them come on and off at different times of day. They were light-activated with a little light sensor, so they turned on at dawn and off at dusk. like a real sparrow would. It also saved battery life in that way. And they were solar powered. There's no electricity or plumbing on this island. Pretty rustic field conditions. So I needed a solar panel to keep these things running for months at a time so that I might be able to simulate a tuner who's producing sounds throughout the time that these young animals are moving around before they depart from migration. Through these speakers, I broadcast special Savannah Sparrow songs, but here's 10 examples. I'll play the one in the top left. Can you hear differences from the last one I played? I can. I've been studying Savannah Sparrows for a decade, I can't tell my animal from the next. But these are sounds that I created on my computer. They have unique elements like this U-shaped introductory note, or these lightning-wool-shaped introductory notes, or this unusual terminal syllable. These are notes recorded from savannah sparrows, from this species, but from the opposite coast, from the west coast, from Alaska, the British Columbia down to Oregon. These are sounds 3,000 kilometers away from our island, and they're sounds that we have never recorded since the 1960s in our study population. So there's species typical elements, but elements that are distinctive, they're like acoustic fingerprints, that if any of the young birds was to learn a song from one of our simulated vocal tutors, we would be able to trace it back to one of those loudspeakers and figure out when and where the animal learned that particular sound. So I used this experimental protocol, a loudspeaker simulating an animal with these slightly weird sounds. ...to play sounds with the young birds on the island from the time they hatched from their nest in June until they left for migration. Then I researched here, oncology, stuff like that. Then I returned there when the young males were coming back from migration, keeping the speakers going. They arrived around April 15th, and we basically get there as exams had ended, and play again until such time that the young females arrived. paired up and every bird was in a pair and then the one cycle of the experiment was complete. We were broadcasting these sounds in their youth and their early adulthood in the following spring in order to understand when they were learning to sing. Then all we had to do was chase the animals around either with a directional microphone like the one in the jet left or with an omnidirectional microphone in the jet right to figure out which songs they all sang. Did they sing a typical song? like would have happened on Tent Island before we started this experiment, or might some of the young animals learn a song that matches one of these simulated tutors. On the outlying Tarsus Island, where these 10,000 gulls are, if you set foot, you'll have a crowd of like 100 massive 1-meter-wing span herring gulls dive-falling. screaming at the top of their lungs, and so you can't get any good recordings of Savannah Sparrows. So we would walk into an area, hammer a stake into the ground, put this up, all the while protecting our head, and then we would run away, and about two minutes later the gulls calm down, and it records for 24 hours. And there's some people in this room who are part of our research lab, and we're scanning through those recordings to try and find which kinds of songs are detected in these long recorders, because we can't be there in person to collect the recording. We have to use these automated reporters. Whichever approach we use, we sample the voice of every animal on the island all year long. And we use this experiment to test a particular hypothesis. The science class, we've got a book that's been written by hypothesis, right? We could define the vocal learning hypothesis as the idea that wild animals learn songs while listening to conspecific tutors. This is an idea that's been clearly demonstrated for laboratory-reared zebra finches. but has never been evaluated using an experiment in wild birds until we started this work. So it was pretty risky work to be honest with you. It took like years to design the speakers, to design the sounds, to log everything to this island in the middle of the ocean, to play back sounds, so it took a long time. And then it was risky because if they ignored The speakers would be nothing to tell you about. So I'm kind of revealing my hand here. There would be no story to tell, no paper to publish. It wouldn't really yield any insight into vocal learning. But we really thought, based on what we read from laboratory animals, that there was a chance that it would. The other missing part of it is there's so many live animals on the island that they could learn from. In the lab, you can have a nestling zebra finch, not hear any nails, and you just have your speakers, and you really stack the deck. that that young animal is going to learn the song you play, but in the wild there's lots of other animals that they could learn from, real live birds that they could interact with. In fact, one of my colleagues wrote about this bird and said, if you'd asked me in advance, I would have said metal experiment with ways to fail, because he thought that they were all going to learn from the island, the live birds of God. But, you know, screw you, friend. One of the great mornings of my recorded working life was the day that this bird showed up. The lower spectrograms from a bird, light blue, black, light blue. L-B-L, which is a multiple, so we just call him Little Bill. And Little Bill shows up, opens his beak, and sings this song. This is a near perfect match with stimulus 7, which is an upper spectrum. So use those colored bars to underline sections of the stimulus that you can see little Bill picked up. He had learned this song almost identically to the stimulus. Let's look at another bird a couple of days later. Yellow yellow like blue shows up singing this song. which is like a perfect match to a different stimulus stimulus then so again these sounds are so fast i can't really tell the difference between them but when you look at the spectrograms you can see the difference from the light left and right side and you can see how these young animals at the bottom have learned song that is a perfect match with some of our experimental tutor songs people we all want to say yes you're maybe like blue black seeing this song which is closest to stimulus nine. Sure he sassed one note instead of making this note going he did this kind of thing but otherwise he's got this he's got these repeated notes here he's got this up slurred bit and this down slurred bit and those elements are all different from the other sounds that we produce and they're all different from the birds that live on the island. All three of these animals and learned their sounds from a loudspeaker that was simulating a vocal tutor. Over the course of five repeats of this experiment, as you build an impressive sample size just like you'll be doing in your independent project in this course, we found 30 young birds that produced songs that matched the stimulus. And that was the song they learned, and each day they learned one song, they sang it for the rest of their lives, providing us with unequivocal support for the vocal learning hypothesis. These animals then learned their songs, from sounds that they heard early in their life. There can obviously be no genetic contribution between the loudspeaker and these young animals. These are experimentally created sounds, but the young animals have learned them during the first year of their life. And so we can take a book like our ecology text, we don't have to throw it away. These ideas that we held to be true from laboratory studies hold up under the magnifying glass of the experiment in wild animals. which is how good science works. You come up with hypotheses, you subject them to correlational studies, experimental studies, testing those ideas again and again in order to gain a deeper appreciation for things like the behavioral ecology and the adaptive significance of different behaviors. All right, I want to tell you a few little anecdotes before I tell you about a couple of other hypotheses we tested with this experiment. There were four birds who learned songs from other subjects, so here's an example. Stimulus 1 was picked up in a first generation bird at this weird terminal section that I've underlined in blue and as soon as the bird learned one of our songs we stopped that speaker we never played that song again. A couple years later a second generation of bird learned that unique element from the first generation bird and that's what states we're at right now. We have these novel elements like little stones in a pond dropped into this wild population. and we're watching them ripple through subsequent generations. That's one of our ongoing areas of investigation in this study. Here's three other birds, four in total, where we have stimulus being learned by a third generation of bird, then we stop the stimulus, and then that bird is talking unusual elements that I created on that computer into a second generation of bird. And we'll go back this spring. Sarah Daube is your GA for some of you. Sarah and I will go back and see if there's any third generation birds this year. Four birds sang songs that were great matches. Here's an example. The bird is, oh I don't have his, oh there he is, blue, orange, green. His first song is a perfect match with one of our singly. He sang it for the first couple of weeks after he arrived from migration. And then he threw it away, and instead, his final song was an island typical song, unlike any of our singly. So that bird, the song number three, others like him. These birds clearly could sing one of the songs we had played, but they chose not to. So they threw that away after the first couple of weeks and for the rest of their life they committed to their one song, a song that was like a typical island song. So something weird is going on just after they arrived from migration. Now I bet a question that's at the front of your mind is how bad did you screw these birds up, Memal? How did these animals live with these unusual sounds? So I was interested in that question. I'm certainly hopeful that I didn't disadvantage any animal I've ever wished to do that. And we did find that all of these experimental birds defended a territory with their song like lots of them, and attracted mates like lots of them. They showed similar patterns of longevity. So here we've got all the animals that learn the experimental songs versus animals that learn typical songs from the island and there's no statistical difference between their longevity. If anything, experimental birds live slightly longer. So we can't find any disadvantage to them. I think we had taught them unusual accents, but they're still capable of engaging in meaningful conversations with the other animals around them. Like if someone showed up here speaking with a Texas accent or a French accent, but in English, we would still realize that we're speaking the same words. So they're still capable of being understood, even though they have these idiosyncratic elements to their song. Was that a question on your mind? I don't know. I better open the floor for a question or a Q&A before I tell you a couple of other hypotheses we tested with this external. What questions have you got about this study, this behavioral ecology study of Spanish-German someone? You have zero questions. Well, that means I've done a really good job here. All sounds clean. Yes, Paige, thank you for asking a question. So, first, you said you had a I love your question, Paige. You're asking about that period after the very young animal flown to Tennessee come back in those first weeks of life we have a little bit of evidence that they learned multiple songs it's like if all of a sudden as soon as you reach puberty you can speak Italian French and English and then you threw the Italian and the French way and just committed to English that seems to be what's happening and I've got some slides to show you about that time period in their life because I was very interested in that question too after we got these first statement it's a great question I'll probably a little more Alright, well let me move right forward then. So, I've described for you a model of vocal learning that originated in the lab and that we're testing in our field-based studies, where vocal learning begins with the sensory phase, often a silent period associated with migration, the sensory motor phase, or the babbling phase for humans, and then crystallization, where they commit to the adult sound. Because of those results that interested me, and Paige at least, I became interested in what's going on in those final days before they commit to their adult song. We know from lab studies that animals'brains are really open systems up to a point, and then they don't keep growing nerves. And the same thing happens for you and I. That's why language acquisition is quite easy early in our lives, but becomes much more difficult after puberty. Our ability to recruit new neural connections into the language centers of our brain becomes limited by physiological changes as we age. But what's happening at the beginning of that, during the sensory motor phase? I got really interested at that time of year to think about which sounds are important, and whether that time of year at the onset of their first breeding attempt, where a few birds are singing more songs than we expect, to figure out what's going on there. And so I came up with a hypothesis, the second hypothesis of the work that I'm describing for you today, that animals will learn songs that they heard both early in their life. six months ago when they were born on this island, and then heard again at the onset of their first breeding season. This hypothesis came out of some observations of other species of sparrow where people suggested there might be a little bit of sensitivity in their brains right at that stage at the onset of their first breeding period. And that's what motivated this idea that they might preferentially learn sounds or retain sounds that they were re-exposed to. And if you think about an animal born hearing all these noises, flying half the world away, coming back, then is the moment of truth. If this sound is important in attracting mates and defending your territory, it's that first breathing period where it's showing up going, well, let's honor the other animals around your singing to try and attract mates and defend territories. If you can fit in in that environment by changing which sounds you're re-exposed to there, that can be a real advantage to you. If you learn those three languages and all of a sudden you end up in Italy. Having that Italian in there could be the thing that sets you on track to commit to that particular language, if we're going to draw an analogy to humans. To test this hypothesis, during three cycles of the experiment, I changed when different sounds were made. Some of the sounds I broadcast only in the needle summer, for the first three months of when young animals were born. Another third of the sounds I broadcast never playing them in the summer, but instead only playing them in their first breeding spring, when they're eight, nine months old. And then the third category of sound, the sound that I put back in both periods, in their natal summer and their first breeding spring. Which category of sounds do we expect to be learned if this re-exposure hypothesis holds any weight? Got my answer? Two? The summer and spring, you got it. If it's hearing it here, and then being re-exposed to it later in spring, it's this third category of sounds that we would expect to be a winner. Now, these sounds, I had the same number of sounds in each group. They were controlled for how long they were played, their amplitude. Every other feature was the exact same, except what stage in life that the young animal heard. So here are the results. The winner overall, Tina, you'll be happy to know, is the spring and summer sounds. Overwhelmingly, of the 21 birds in this part, 90% of the 21 animals learned sounds that they had heard in their youth, they flu-sucked, and then they heard it again when they arrived from migration. This offers a strong support for that big exposure hypothesis idea that appears to be important to hearing the song again and retaining it. Now, two birds, 10%, learned songs they had only heard in their youth, And then they didn't hear again when they arrived for migration, because we weren't playing it. So you don't have to hear it again at the start of your first breeding spray. These two clearly didn't need to. They sang a song that they'd only heard in their navel summer. They have no bird, zero percent, ever, we never had any evidence of any bird being able to produce a sound that hadn't heard in his navel summer, only after it had returned from migration. And this suggests that these animals have to hear the sound in the first three months of their life, or they're never going to learn it. So, raise your children is the moral story of humans, right? They have to have that exposure, and they're laying down lots of information in their brains, but then that information is refined based on whether they hear it again or not. And if they hear it again, they're more likely, most likely to choose that song to retain into adulthood. This offers a strong support for the idea that animals retain sounds that they hear again following their first migration. Strong support for the re-exposure hypothesis. We found that, as we got interested in this time period, the first weeks following northward migration, a lot of birds sing multiple songs. So here's a bird singing English, French, and Italian. He sang song one a bunch, then two, then three, then two, then three, then one, switching back and forth, but only for a couple of weeks. Then he threw them all away, and he kept which one? He kept song one. I can see that chip and that dash there. That's quite different from these others. So this guy had three songs in his repertoire, but threw them all away in favor of one. Lots of birds did this. And we call this behavior overproduction. Again, to return to my human analogy, it's like a young teenager who's fluent in multiple languages but throws all of them away when they start getting ready to really hit puberty in favor of just one language. They're singing three, two different songs, but jettisoning all but one. And this is a phenomenon known as overproduction. It's like exhibiting a larger number of... It's like having a massive vocabulary when you're 12, and then you go to a normal vocabulary when you turn 13. That's the kind of thing that we see happening in the first weeks of spring for these animals. Interestingly, if they live two or three or four years, they don't do this in any future springs. Only in their first spring do they exhibit overproduction. Now, some work on a different species of sparrow in California has found the same thing. They overproduce and undergo a period of attrition. Attrition just means getting rid of some things down to their normal repertoire size. In Spanish, that's just one song. And so authors out there came up with this idea of selective attrition. Behavioral ecologists were interested in what's the selective advantage of a behavior. Is there a selective force driving them to choose one of the songs if they overproduce and then choose one of those songs? So to phrase this as a hypothesis, and my final hypothesis for the day, is the selective attrition hypothesis that after animals produce multiple songs in their first mating spring, they will retain songs that match the songs they hear around them. This is an idea that grew out of the exposure hypothesis. So, we recorded lots of birds. Here's the example. His name in the band are Split, Split Green, and the Split band is just half white and half black. So he split Split Green, and Split Split Green sang two songs, switching back and forth between them, until he threw one away. Which one did he keep? Song one or song two? You should be able to tell by looking at the spectre. Good, good. Come on. Thank you, thank you. Chloe? Song one. Yeah, so we compared his song one to all of his neighbors. This guy, he was a young male. showing up, started the territory, and he had four other males singing in territories around him. Here's their songs. And using software in our lab over in the biology building, we compared his song one numerically to all of the songs of his neighbors. These are adult neighbors, so they only have one song in their repertoire. And then low number represents a very similar song. You see how similar split split rain song one is to blue orange green here? We've got that dash, which is quite different from like pew-poo, or like cha-cha. So this animal has a very low, a very similar song and a low acoustic similarity score. We can do that same thing for a second song, comparing song two acoustically to each one of his neighbors'songs. And what we found is that the song he retained was the song that had the best match with his neighbors. We repeated this analysis with 27 different young people, and in every case they're keeping the song that is the closest match with one of the animals around. Birds retain songs that are in their mind from the first three months of their life, six and eight months ago, and they're listening to the animals around them and using that information to guide the process of attrition. It is a selective process. They are selecting the song that matches their neighbors, offering us support for the third and final hypothesis that I described to you today. Support for the idea that attrition... overproduction of polypantrogen gives these animals the ability to speak many languages and find the one that is the most effective communication signal with animals around them. In this paper, we took it a little further. Here on the x-axis we have the acoustic similarity scores, where a very similar song would be on the left side of the x-axis, and a very dissimilar song would be on the right side of the right axis, and we compared that. Animals who really fit in acoustically with their neighbors, versus males who sound really different from their neighbors, we compare this to how many fights they got. That's our y-axis here, which is a measure of aggression. And you can see that when males produce songs that are good matches with their neighbors, the left side, they end up in fewer aggressive encounters with their neighbors. So there is our adaptive significance of this program, of having your mind... be ready to hear lots of song in your youth, you have to go to silent period, you fly south for the winter, then you come back, you listen to the sounds around you, you're overproducing, you're honing in on the song that is the best match to the neighbors around you. And when you do that, you end up with this resource defense mating signal that incites the fewest fights with your neighbors. There is a direct advantage to engaging in this behavior. This is me pulling behavioral energy strongly into the... That's from this lecture, right? We have come to understand the value of what might at first seem like a fanciful behavior, trying to figure out why animals sound the way they do, but we find that there's a real survival advantage here. Fewer fights with your neighbors if you follow this particular learning program. In other words, by retaining similar songs to their neighbors, birds end up experiencing lower levels of territorial aggression. during the rainy period. That means energy savings. That means fewer injuries from the fights with your territorial leavers. The final point I want to make is that all of this work we've done actually scales up at the population level to show us something about how the entire population of San Amsperas on Kent Island sounds. So each year for the last 10 years I set up with posts and 16 of these recorders into gull land. Lots of gulls swirling around me and it pooped on me. It's the worst, especially because there's no plumbing on this island. It's a bucket shower. Anyway, that's not the point. We traveled around to each one of these sites on our main island. Each black dot is about 50 meters from the nearest black dot and that's a site in the meadows. The dark green is the forest, the light green is the meadows. And every year we set up a recorder 24 hours in order to survey every bird on the island. At the beginning it was in order to find those birds who might be vocal learners. But as we went forward, we looked at the island's typical songs, not our experimental songs, but the typical songs of the island, and we found there's a couple of really common themes. I've color-coded them here. There's the yellow theme, the red theme, the purple theme, the blue theme, and each dot on the right-hand side is a different bird singing a different theme. It's a lot to take in, so let me hone in on the most northerly part of our study site, Hay Island, and we'll look at just one. Each dot is a male, the color shows you which island typical song he was singing, and the dots shows the proximal territory boundaries. Now what do you see right away here? They end up... go ahead Chloe. Brilliantly put, Chloe. They're attracting other animals, or better than attracting, they're ending up in these little clumps of yellow, which is one of the things you know, and they end up in these pockets of similar sounding animals. Yeah, we've got a big pocket of yellow, a little pocket of yellow on the other side of the island, a pocket of blue, poor purpley up here, he doesn't have any neighbors, maybe he didn't care, a pocket of purple down here. This behavior of learning can be reduced, overproducing at the onset of adulthood. Undergoing selective attrition based on what you hear is the mechanism that drives a dialect. They end up in pockets of similar sounding animals because of this individual level behavior. And so we see structure at the level of the whole population in terms of who sounds like who, because of the individual things that these animals are doing to maximize their chances of survival. I'm going to skip two slides and go to my conclusions. I have today shown you work out of our research lab that I'm really proud of that I've worked on over the last decade. This is experimental evidence that wild birds learn to sing based on sounds that they have heard early in their life. We found that birds preferentially learn songs that they hear early in life but then hear again when they are young adults returning from migration. And at that point, as they arrive in their first spring... They are overproducing, producing a larger than normal number of sounds and undergoing a process of attrition. It is selective attrition because they are choosing from the library sounds that they have laid down as memories of their youth, the sounds that are the best match of their adult environment and using those sounds to interact with other males and other females. And the ones who learn the most similar songs end up with fewer aggressive encounters with their neighbors. There's no part of the textbook you can read about this, but I want you, I've spent time on it, so I think it's fair grounds for next Thursday's exam. If you want to read the specific details, I wrote this paper and I try to write in an accessible way. not always writing in passive voice, but active voice, the same way we'd like to teach you to write for your independent project in this course. If you go on my website, you can find, if I was to point you to a single paper that best summarizes the work I've described today, it's this one on my website. Current biology is the journalist called Wild Birds Learn Songs from Experimental Vocal Tutors. Now this work that I've done, I've told you that I'm going to make you work with a partner. in your independent project here. This work that I've done has many, many partners. First of all, this work was funded by the Natural Science and Engineering Research Council of Canada. I have four collaborators, profs at U Windsor, University of Guelph, and Williams College in the United States, and many student collaborators, Sarah Dovni, many of you know. Abby Hensel I met when she took ecology about 10 years ago and lots of students have been involved in this work lots of people have been involved in the logistics and the field assistance and then people in my lab some of whom are here today are playing a heavy role I need to update this slide to add our new cohort of researchers a lot of people helping to scan through those recordings in our study of vocal learning and wild birds.

Good morning, everybody. We will now begin. Welcome.

Please create a distraction-free learning environment for yourself and for the people around you. Something's making my mic run. Welcome to ecology.

What are we at? Lecture number five or so? Here we go. Six.

There it is right there. Lecture six, behavioral ecology part one. And today we are going to break from the textbook for the only time in the semester because we have now reached the best part of ecology, the topic of behavioral ecology. Why is it the best? Because it happens to be the branch of ecology where I conduct my research and we're going to talk about it.

So what I want to do is do a little introductory to the topic of behavioral ecology that is going to carry us through the whole week because on Thursday we will deal with the textbook chapter on this topic. But today we will divert from the textbook and talk about the behavioral ecology work that we do in my lab on vocal learning in wild birds. That's our goal for the day.

Let's do our logistic break now instead of in the middle. So Lab 3 is this week. I posted it early this morning on the website under the lab section. There is a Word version and a PDF version.

They're identical to each other. We also posted the independent project. the big thing that we're working towards, that all of the other lab activities lead towards.

So you'll see two things there that you're going to want to read. The lab three, which contains two assignments, more on that in a minute, plus the overall big picture view of what we're doing with the independent project. And I'd like you to find both of those. I've only posted that one as a PDF because you don't have to fill out any information in there. But it contains the overall...

What is it, 20% of your final grade arising from that independent project? It also includes the marking scheme of how the GAs will be evaluating you. And of course, a clever student like you knows that before you hand something in, you want to see what the GAs are doing to evaluate you.

You'll find all of that. Don't forget, Laboratory Assignment 2 is due this week by email before your lab starts. We had a GA meeting this morning, and some GAs said we asked them to hand it in in paper, others by...

email. We decided let's be consistent and let's just always go email. They'll explain more this week, but everything can be submitted by email. It means that someone who doesn't have a printer is not up the creek.

So you can submit everything from here on by email. Your GAs will explain more this week. If you're unwell, please do not come to class. Please listen online and please don't come to lab so you don't make others sick, but you will need to...

email Candy and your GA to make sure they know and that email should be received before the lab begins, before the time that the assignment was due. Can't get the assignment done because you're really sick? Get well soon and then hand it in. We won't penalize you if you're sick. Take the time you need and then include it, getting it to them as soon as you're back in good health.

So this week's lab, lab three, has two assignments, assignment three and assignment four, that arise. Remember on page three of our course outline, you've got this list of what happens each week. Here we are, September 26th and 27th, week three.

In the light green at the bottom, you'll see assignments three and four are given to the students. And assignment three is due on October the 1st, which is a weird day. It's a Tuesday. Whoops, I forgot a space right there.

And then assignment four is due after the reading week. This is all clear if you read this, but this is one week where the single document includes two assignments, assignment three and assignment four. Your GAs will explain more about that. Here's a screen grab of the lab section where we've got lab three in PDF format and Word format and the ecology independent project.

Any questions before we move forward? Yes, your name? Adina?

I love this question. Can I please talk about the midterm, which occurs a week from Thursday? I've got slides ready for Thursday and Tuesday that I will share example questions with you from the lab, from your midterm, and I will share strategies about how to succeed on a Dan Menel-ridden midterm.

So that's coming up. on Thursday and Tuesday ahead of the midterm exam which will take place right here or in SAS a week from Thursday. I'm gonna mute myself for a second and figure out why the mic's acting crazy. Bear with me for a moment.

Do you have any other questions while I'm trying to fix this? About labs? About the midterm?

Anything? Yes, Donny. Good question, Donnie. You have to partner with people within your lab section, as the GAs will explain.

A few of our labs have odd numbers of people, so the GAs will allow one group of three, and they'll explain all the details of that in lab this week. Oh, Manil, I hate writing labs with other people. Sorry. In real life, like all the work I'm about to describe for you that we do in my lab is all done as a team.

And so scientific teamwork is a really important skill that the GAs and I want to teach you, may force upon you in this independent project. So you can be ready for that this week. You could be planning who you want to work with. We'll leave that up to you.

If you don't know anybody, we'll pair you up when you come into the lab this week. I think I'll leave the rest of it, Donnie, and everybody else for the GAs. They're in charge and they'll explain everything when they see you.

Right. Fingers crossed that this is better. I'll just stand here if I need to.

Seems good so far. OK. Let me orient you in this course. What's ecology?

That's a good question. Ecology has many definitions, but a good one is the study of the relationships between organisms and their environments. We started in our first lecture talking about symbiotes and relationships. and the fundamental unit of ecology being the ecosystem.

We then talked about both biotic and abiotic environmental influences and how ecologists spend their time trying to track the inner workings of biotic and abiotic environmental influences. That included a lecture on ecological energetics and how autotrophs capture energy from the sun and form a key part of the trophic pyramids of energy transfer. through food chains and food webs. We talked about nutrient cycling and how all of the nutrients that are necessary for life move through different forms and different compartments during ecological processes.

Most recently we talked about population ecology. What is a population? What features define the growth of population and the factors such as pecundity or survival that influence population factors. Going into the midterm, we have three more lectures. Today and Thursday, we're going to talk about behavioral ecology.

Today is an incursion from the textbook as we talk about my behavioral ecological work. Thursday is focusing back on the chapter six of the textbook that deals with behavioral ecology from a more general perspective. Finally, a week from today is our last topic of stuff that will be on next Thursday's first term test. We will talk about physiological ecology and how autotrophs and heterotrophs use physiological systems in order to live in the world. Good?

So there's our math. That's everything leading up to term test club. The behavioral ecology is the study of the behavior of organisms with a special reference to the adaptive significance of those behaviors.

Why on earth? When an ungulate carry massive antlers that could weigh as much as its entire head and impede it from its ability to move around, why would it do so? Because there is some adaptive significant value to that, some value that serves and offsets the cost of that trade, bringing a benefit to that trade. And you may well know that in the context of ungulates, antlers are often having an adaptive benefit of being useful weapons. during battles with other male ungulates in competition over resources.

Behavioral ecologists spend a lot of time thinking about what kinds of activities and behaviors do organisms engage in in the natural world that give rise to their survival or to their death. Was the lizard well camouflaged or not when it was depredated by a snake, for example? Behavioral ecologists spend a lot of time thinking about how do organisms defend resources.

All of us need access to the right source of food, whether for an autotroph trying to gain access to the sunlight, or an emertroph trying to compete to gain the most nutritious and valuable food or water that is necessary for our growth. And so a lot of behavioral ecology is defined by figuring out the ways that one species or another engages in different forms of competition. I highlighted the way that plants are almost behaving, and many biologists do study plants, thinking about two plants in a race for their food, being given sunlight, and trying to gain a competitive advantage by reaching that sunlight first, and help competing in other organisms, competing for the same resource. Or this rhinoceros beetle who's trying to compete for a little area where it can display and try to attract females who don't have these rhinoceros-like projections off their carapace.

And they will do that just like a deer would, by using their armaments in order to battle with other members of the same species. The behavioral ecologists spent a lot of time thinking about mate attraction. How do organisms attract their mate with... big antlers, or with big sounds, or with big smells, in the case of orc animals that communicate through pheromones. Behavioral ecologists spend time thinking about which behaviors are important for reproduction.

Some of the most highly evolved behaviors in the animal kingdom, elaborate courtship displays of wandering albatross that might meet a courtship period that lasts much longer than when you met your romantic partner. Are they from spending... weeks to months deciding if they like another animal by engaging in these elaborate courtship displays in order to choose which partner to reproduce with. After animals have found resources and attracted mates, behavioral ecologists spend time thinking about how do parents interact with their offspring. We'll return to the mysterious case of a male lion and a female lion, and seemingly mistaken behaviors that males often exhibit engaging in infanticide.

But it is a behavior that ultimately we strive to understand its adaptive significance by figuring out why would a male lion ever kill a cub? And many of us know the answer from watching Disney movies, of course. Behavioral Ecologists will spend time thinking about what's the difference between last spring where there was one bird that saw that window while I was studying for final exams, singing a song all by himself, and this morning I saw that same species of bird in a flock of a thousand flying over South Windsor and LaSalle.

What are the different factors in the environment that give rise to an animal to move out into the world as a solitary individual versus gathering together in groups? These are the questions of behavioral ecology. And they're the kind of questions I find most exciting, that I got really tuned into when I was doing graduate studies, like your GA's, a lot of your GA's are behavioral ecologists as well.

So I've talked about how this course is a sampler of all of the different branches, or many of the different branches of ecology, at least the longest standing branches of ecology, and this week we're focused on behavioral ecology. So... Like most of your professors, I spend 40% of my working life teaching, and I love it. But I think it's imperative for you to know, as undergraduate students here at the university, that like any good university, any PhD-granting university, most of us also have another 40% of our working life that is devoted to research.

So the work I'm going to describe for you today is the work that I spend a lot of time doing. 40% research, 40% teaching, and then 20% service defines the life of a university professor. Service is things like serving on committees, serving on a group I work with as the Associate Dean of Graduate Studies and Research to help our graduate programs and the research programs with my colleagues to succeed.

So that is the ratio of what professors do. And I want you, as second-year undergraduate students, to recognize that profs have this other life, too, where we communicate with other colleges from around the globe, in my case, behavioral colleges, who are working on different topics at different universities. And this talk that I'd like to give to you today is a talk that I get traveled around the world to deliver sometimes. I gave this talk in France and the United States over the course of the summer at big conferences.

And it is important. part of my life just as it is for any of your professors to do research, establish their own niche of research that they're working on, and gather together with other experts across the globe to share in those ideas. So, we have lots of work in our lab, but today I've chosen to focus on one project called Vocal Learning in Wild Birds, the dynamics of vocal learning in nature.

And if my slides look a little weird, it's because these are the slides I use to go out and present to other people and advertise my website and my Twitter handle. You can follow me if you want. I won't follow you unless you ask me to follow you. Well, I don't make people hear you're on Twitter anyway, but if you are and you want me to follow you, let me know.

But sometimes that feels invasive. I don't want to. I force myself on you. Anyway, here we go. Okay.

Before I get to the research talk on local learning in wild birds, let me tell you about the framework of the work that we do in our lab. In our lab, we study the behavioral ecology of animal communication. We do a lot of reporting of wild animals and use the sounds that they produce as a window into their minds to try and understand what does an animal want in a reproductive partner, when is it important to defend resources.

We can find out a lot of answers to the big picture of behavioral ecology. questions by studying patterns of animal communication and really get an adaptive significance of the different behaviors. That is the heart of behavioral ecology, figuring out why certain behaviors are beneficial or costly to an animal. And along the way, we use the tools of recording and the tools and the ideas of behavioral ecology to try and protect...

animals whose numbers may be in trouble. And so it's not the work I'll focus on today, but some of the work that will pop up a little bit later in this course is to do with animal conservation as well. We find these themes in our lab and today's talk is about the first theme. I've sort of five different talks that I give at different places over time, but today I'm going to focus on maybe my favorite one on vocal learning and cultural evolution in wild birds. If you're interested, we also study communication networks.

What happens when we recognize the fact that a lot of animals live in earshot of conspecific animals and exchange information? They're not just one male singing to attract one female, but there's lots of listening females and lots of other singing males out there. And so while animals can be visualized as a network, networks provide us with some mathematical tools for understanding their behavior. We study female signals.

When you wake up... in the spring and a bird singing loudly outside your window, you're hearing a male. Here in the temperate zone, only males produce those long, musical sounds that we call birdsong. Females are nearby, but they're largely silent, producing just quiet little notes that both sexes produce.

That's common in the temperate zone, but in the tropics it's quite different. In the tropics there are many species where both males and females sing, and by working in Costa Rica, Colombia, and Mexico, We try to understand why those behaviors evolve in the tropics, and why don't they evolve in the temperate zone. We study diverse social signals.

Myself and my partner, my life partner, my research partner, Dr. Stephanie Busset, who you might take up your courses with after ecology. For example, one time we found these brown toads in Costa Rica that turned bright lemon yellow for one day of the year, like a chameleon. bugger toads, an undescribed phenomenon and we found that they're doing that in order to gain a reproductive advantage.

It's a behavioral ecology question, finding a pattern of a behavior in a wild animal and asking about its adaptive significance. Finally, we do some conservation bioregistic studies like we have microphones all around the Great Lakes, pointing up at the night sky in order to sample warblers and other birds as they fly by in migration. as a tool for surveying how their populations change over time. Those are five of the research themes in my lab, and today I'm going to tell you about the first of them. Some of the broad techniques that we use in our lab include field studies.

All of the work that I do involves going out to study animals in their natural environment. In my opinion, that's a little more interesting than studying animals in the lab, and it's also a lot more fun to be able to go out and spend time outdoors with animals. We do a lot of recording.

That can be with, well, I'll show you some pictures. You should always have a typo picture where I've turned up your microphone, a parabolic reflector, so I could record you, but I wouldn't pick you up very well. It gives me a very directional column of sound.

This kind of recorder here is an omnidirectional recorder. I could plonk this right here, and it would record the entire room in an omnidirectional. We do a lot of sound playback.

When you're interested in the evolution, the behavioral ecology, rather, of acoustic signals, you can use a loudspeaker to simulate a person. or a frog, or a monkey, or a whale, and then figure out how other animals react to it. And finally, we've helped to find a bunch of radio telemetry approaches, where we catch a bird, put a little radio tag on it with a backpack kind of thing that straps around his legs, let it go, and then we can track that animal in order to figure out where it migrates to, or how far the young travels from its nest until it ultimately eats.

Alright, with that background, we dive into this topic about vocal learning in wild birds. So here we've got six different groups of animals. Songbirds, hummingbirds, and parrots. Cetaceans, which is a scientific name for whales and dolphins.

Bats and hounds. Now these six groups of animals share in common a behavior that no other animal in the animal kingdom exhibits. And that is the behavior of vocal learning. where young animals have to be exposed to adult sounds during a critical window early in the animal's life if the animal is ever going to produce normal adult sounds itself.

It's true for you, and it's true for the Savannah sparrows that I'm going to tell you about today. It's not true for your cat or your dog. If you isolate a cat or a dog at birth from its parents so it never hears a meow or a woof, It will still grow up to produce normal meows and woos. There are sounds like most animals in the animal kingdom are innate.

They just have to grow up and the genetic programming to produce those sounds is contained in their genes. But that's not true for these six and only these six groups of animals. Quite interesting in the case of humans, no other primate has this behavior but we do. If you are isolated at birth or if you are born deaf, You know, a deaf person, their voice sounds slightly different. And that's because they were not exposed to typical adult sounds in order to hear them early in their life, and so they don't produce the typical sounds as adults.

It's quite a rare behavior, but it's an exciting behavior. And by studying birds, we can come to understand how this behavior works in a way that we couldn't always do with humans. So by studying vocal learning, the April College has been working on... The mechanics of how this works, the adaptive significance of different behaviors, for many, many decades.

And we've developed a good model of how vocal learning works. Most animals, including you and me and songbirds, have a sensitive phase that's restricted to a narrow window early in your life. And you have to hear sounds during that critical window in order to produce them as adults.

Then many, but not all, animals undergo a silent period. Humans don't, but birds do. This is usually a copy with migration sound, or like a chickadee that doesn't migrate, just hunkering down and surviving the winter.

Then comes a pattern we all have of the sensory motor phase, which is a fancy word for babies babbling, producing lousy copies of adult goo-goo-ga-ga kind of stuff, that then start to get more gooey and gah-y as time goes forward. The sensory motor phase is producing poor copies of adult sounds that get better with practice. And then one day, crystallization occurs.

At one day, and it happens very quickly, and my kids, you know, over the course of weeks, they went from goo-goo-ga-ga to real speech. That is called crystallization. It is the point at which neural activity becomes more fixed, neural connections become rigid, and they stay that way for the rest of your life. Like, if you're trying to learn a second language at your age, you can still kind of do it, but not as well as, like, my 10-and 11-year-old can. Our brains become fixed at a certain point shortly after puberty in humans, shortly around the age of eight months in birds, where they are much harder to learn new sounds, or learn them at least with a good accent.

So this is the process of vocal learning. That's how it works. We have studied this behavior in laboratory-reared animals for decades and decades. Like this one.

You know this species? Maybe someone has one of these at home yet. It's the zebra finch, which is like the white rat of the behavioral ecology of birds on the world, because you can hear that in captivity. We've been studying it for a long time. It allows us to get at that model of how global learning works.

And we can manipulate them in a way that would be pretty unethical for me to manipulate you, to remove you from your parents and play you different sounds at different stages of your life. You couldn't do that. But we can, at least we historically consider that to be an ethical approach with wild birds. But what about when you go outside of the lab?

What if you look at animals in their natural environment, where they're not just hearing certain things, where they're migrating, interacting with very broad groups of other individuals, and there's environmental noise, anthropogenic noise, or naturally occurring noise? Do all of our models of vocal learning hold up in the wild? There are certainly lines of evidence that they do. Here's one good line of evidence. It's correlation evidence.

Someone went up and down the coast from British Columbia to Washington State to Oregon, California is right down at the bottom there, recording this species called the white-crowned sparrow, the name of the species is important, but as they went, they found all the animals in a particular population sounded similar. And then they crossed a line and they all sounded a little different. And they all sounded a little different the further south they met. This is called a dialect and we have it in humans too, right? That someone from Texas sounds different from, uh, I'm not going to do a new land accent, but humans have little dialects too.

And just like in birds, this is consistent with the idea of learning sound where you were born, dispersing on average some short distance and ending up singing sound. Producing speech in an area near where you learn it is consistent with the idea of vocal, although it's not an experimental test of it. There's a typical White Crown Stereo song, it's the top one. I've never shown you these weird squiggles before, have I? This is called a sound spectrogram.

A sound spectrogram is the way of visualizing sound, it's like a piece of music. So we've got that beep and in a way of visualizing sounds so that something that occurs really quick can be tracked very carefully in order to figure out what are the differences. And you can see the differences are quite pronounced in California.

So the objective of the work that I'm going to describe for you today was to use an experimental approach to study vocal learning, but for the first time to do this outside of the confines of a laboratory. To study in wild birds where all of the noisiness of nature, the interactions with competing mates, rival individuals, and migration comes to bear, and study the process of vocal learning in a wild bird. That's the objective, and the study animal is this amazing animal, the savannah sparrow. The savannah sparrow is a, some people might call it an LBJ, a little brown-jogging. It's not going to win prizes for the best looking bird.

You can see one in the grasslands of Ojibwe for like another week before they fly south, but they'll be back in the spring. They're a typical sparrow, short seed-crushing beak, mostly brown, a little bit of yellow above their eyes. Nothing fancy until they open that beak and sing this great song.

So here again is the spectrogram, frequency on the y-axis, time on the x-axis. Every male Savannah sparrow sings one song, and it sounds something like this. Kind of insect-like, a little bit thin and buzzy, high-pitched. But when you visualize it as a sound spectrogram, you can see there is a lot of complex information in there.

These high-pitched introductory notes, this middle section, which is highly variable between individuals, the buzzy grasshopper section, and this terminal trill. They're singing this song a lot throughout their reading period. Our study site is in Eastern Canada.

Instead of just going to Ojibwe, I take my family and my students across the country out into the middle of the Bay of Fundy there. I'll explain why in a moment. In the middle of the Bay of Fundy is this island called Kent Island, where there is the Bowdoin Scientific Station in New Brunswick. It's an American college, Bowdoin College, that runs this station, but they let us work there, thankfully, because this is an amazing island.

that is covered with savannah sparrows. Here's a view from the highest hill on the island. It's a small island, it's like the height of the campus.

It's about three kilometers north to south and you can see it's pretty thin east to west and there's a couple of other little islands. You remember the Bay of Fongyin should go. They have the highest tides in the world, but high tide just ruins other water and low tide is fully exposed.

About 30 feet between high tide and low tide. So these other islands are continuous with their main island at low tide, and they become separate islands. So this is the grassy area where the Savannah Sparrows live. There's lots of other cool animals on this island, like herring gulls, much bigger than the gulls we see in town here, which are ring-billed gulls.

These are massive gulls. They're the bad guys in Puffin Rock. Are you the age that you might have grown up watching Puffin Rock as kids?

Or maybe you're that too old, I don't know. Anyway, very nasty creatures. They'll dive on you and try and be...

crack her head open if you get too close to their nest. But there's 10,000 of them on this island. There's also eider ducks.

Have you ever heard of eider down? Eider down is a prized substance to make really expensive like red coats, right? It is a very good insulating down because these animals live in zero or sub-zero waters in the ocean.

And they all smelt extinct from North America except for this island. Kent Island, where the eider ducks held on and were protected by philanthropists from the United States. He said, no hunting eiders on this island.

And from that, since the 1930s, this species has rebounded. There's a bunch of little albatrosses, about 4,000 of them, that live on this tiny island where there are no mammals, except for us. So there's nothing to eat them.

They live in burrows underground, and you only see them at night. Very cool animals. And best of all is this amazing little bird, the savannah sparrow. There are about 300 breeding pairs of Savannah sparrows.

It goes up and down each year. You know about carrying capacity in a wild population. It fluctuates around a long-term mean. At our long-term mean, we need 300 pairs or 600 or so individuals.

Every year when we get to Kent Island we capture every bird we can in the middle of the island. And we do so with these nets that are called mist nets. They're called mist nets because you can't see them very well.

They just create a mist-like appearance. A bird doesn't see them. You can see the nets all billowing up in the wind there, but here it's starting to be spread out by an undergraduate researcher and my collaborator here on the poles.

It stretches out kind of like if you stacked Four volleyball nets, or badminton nets, atop each other, but with very, very thin threads. And a bird flies into that, and ends up caught in a little pocket of the net, and then we race up and get the animal out, making sure it doesn't injure itself. We are very good at handling birds.

And then once we have the bird in the hand, we process it as quickly as we can, usually two to five minutes, so we have the bird out of the net. And we do a couple of things that any behavioral ecologist or ornithologist We do when they have a bird in the hand. We collect feather samples by plucking one of its tail feathers, a couple of its back feathers. We can use those in genetic analyses. We can use those with some chemical approaches.

We can figure out where it overwintered last year by looking at stable isotopes and questions like that. We can take a little blood sample, just a pinprick of blood that we collect with a capillary tube. That allows us to figure out which animals are related to each other and to the order to address questions about who can breed. or about paternity and questions like that. And then most importantly, we give every bird that we've captured a unique identity.

We're licensed banders by the Canadian Wildlife Service and anytime you band a bird, you have to put a little numbered band from the Canadian Wildlife Service, the silver band here. If you've ever spent time at Holiday Beach, has anyone gone to Holiday Beach? They have a great bird banding program. They're always looking for people interested in learning these skills. If you want to get introduced, reach out to me.

They just, they're a migration monitoring station, so they're just putting number bands on birds, hoping that someone, somewhere else halfway around the world might catch that bird and we'll figure out their migration route. But we're, in addition to those number bands, we're putting little colored bracelets on their legs. Like this guy's got a black on his upper left leg, a red on his lower left leg, and orange on his upper right leg. And so we could just... A breedie, that is B-R-O, the first letters of each color, black, red, orange, or instead of having to say B-R-O or black, red, orange, we'll just call them bro.

See, so then we'll come back, oh, did you see if bro had attracted a mate yet this year? No, but I saw that leader, white, blue, yellow, red, was starting to affiliate with owl, orange, white, light blue, down past the tall pine tree. This becomes a way that we can lift up our monopters and go with orange.

white light blue that's that particular bird we can keep a record of it and we know when he was born where he was captured who he made it in last year when he arrived and left for migration so this is a way of attracting each individual and because i can't tell the look of one samantha sparrow from the next but i can look at the bands on their legs and use that as an individual like them so this population has been studied in this way since the 1960s It's one of North America's longest-running field-based studies of the behavioral ecology of a wild micro-48 animal, where the animals have been captured and individually banded. Here we've got yellow, red, white, so Y-R-W-U-R-M. That one doesn't really have any saccharin. Don't tell them about that yet. Okay, so we've decided to populate for a long time, and the reason that it's worthwhile to go out in the middle of the ocean and take this long journey into eastern Canada is that this population has unusually high natal cycles.

phylopatry, which is a fancy way of saying that birds who are born here return here after migration. And that's quite rare in most animals, including mammals and local birds. After they leave the area where they're born, they disperse away.

That might involve migration to the south and coming back to a different population, or it might just be moving away from where you're born. And that's true of animals and birds and many other species. Why do so many animals have this post-juvenile period of dispersing away from the area where they're born?

Put your hand up for me. Good. One person, two.

Good. You were first. To mix genetics with other populations to avoid any breeding. Paige, is that it?

Do you agree? You had your hand? Are you in agreement?

Good. You're right, so thank you. You don't want to meet with your siblings or your parents because usually the offspring are not viable, with some very rare exceptions that you learn about in classes like evolution or genetics.

And so there's strong pressure for animals to avoid returning to where they were born. For some reason that we don't yet know and we're studying it, the animals in this population don't do that. Maybe it's because they're born on this little island in the middle of the ocean and they have this particular mark of a place they want to fly back to.

But whatever the reason, they return to this island over and over again. And if you care about vocal learning, this presents a special opportunity. I can record every sound these wild birds learn.

and then have a chance that they will return from migration and I'll be able to record them and hear what they sound like as adults. Or maybe I can even use loudspeakers to manipulate the sounds that they hear in their youth and have a chance that I'll be able to find them given this high rate of natal cycle. So the annual cycle of these birds, these birds, like so many temperate animals, are born after the spring period. Females that arrived from migration got the nutrients they need mostly through caterpillars so that they can start the late eggs.

Those eggs hatch in June, and the life of those Spanish Barrowbegians. They remain on the breeding area, whether it's our island or here or wherever, for about three months. Rowing, getting their feathers longer, learning stuff like how to fly and how to forage.

And then they take off in mid-September, flying to the over-October winter in the southern United States. We know from those little bats. exactly which farms they're going to in Tennessee, North and South Carolina, Florida, Mississippi is where some of our animals are living. Spring starts to arrive and males arrive first.

Males arrive first from migration in mid-April. Females arrive two or three weeks later. They mate and the process begins anew. That's the annual cycle.

They live two and a half years on average. The longest lived animal ever was seven years. You know their survivorship curve, tech G's survivorship curve? Okay.

Song, the thing I'm really interested in from a behavioral ecology perspective, trying to understand the adaptive significance of vocal learning and singing behavior, is common when these animals are on their breeding territories, but they don't sing when they're in the winter. In the overwintering areas, when we find them in the southern United States, they are not singing. This is stuff that is only found during the breeding season.

One of my master students, a French woman named Ines Morin, and I recorded many birds over a very long period and we found that as soon as males arrived from migration they sing a lot. Here's 4 a.m, 6 a.m, 8 a.m, up until 10 o'clock at night. They sing the most at dawn and then it goes to lower levels over the course of the day.

Most birds do this. You know this, right? In the springtime you get that huge burst of birdsong early in the day called the dawn chorus.

When females arrive from migration, they change their singing behavior. They sing the most in the evening. Any guesses why they would make this change during a period of female arrival? Yes, I forgot your name.

You're my colleague. Yeah, why would it be useful to sing at night? In fact, it's because the females are arriving, and like most little birds, they fly at night.

So I think they're singing at dusk, you're right, to attract the mate, to sort of be like, hey, any females up there? I'm down here as a reproductive male. And I think that's why they're singing the most in the evenings, to attract the mate. Then, when they're really busy, they pair up, they reproduce. When they're feeding the young, feeding the nestlings, or after the nestlings can start to fly, they feed all around and feed them some more.

they sing at lower levels, and then when those fledglings are present, their song is at its lowest level, and then it will disappear in September until the next year when it's patterned along. So that was one of our first projects, to figure out when they sing. We find they sing at dawn or dusk and throughout the breeding season. A lot of variation in when they're exhibiting this behavior.

But to return to my primary objective, using experimental approach to study song learning in wild birds, to address that objective, I had this idea. I'm using a loudspeaker to simulate a tutor on the island broadcasting songs that I could use in an experimental context to figure out whether young Savannah sparrows are listening to sounds they hear in their youth and then later producing them as adults given the high rates of natal site phytopathy in this population. There were no good speakers I could find, like the little Bose or Sonos or whatever. Those only last a very brief period.

They're not very fancy. So I worked with engineers at an electronics company to design speakers that were weatherproof. I could leave them out for three months at a time.

They were programmable, so if I had multiple speakers, I could make them engage in interactions between different tutors or have them come on and off at different times of day. They were light-activated with a little light sensor, so they turned on at dawn and off at dusk. like a real sparrow would.

It also saved battery life in that way. And they were solar powered. There's no electricity or plumbing on this island. Pretty rustic field conditions. So I needed a solar panel to keep these things running for months at a time so that I might be able to simulate a tuner who's producing sounds throughout the time that these young animals are moving around before they depart from migration.

Through these speakers, I broadcast special Savannah Sparrow songs, but here's 10 examples. I'll play the one in the top left. Can you hear differences from the last one I played? I can. I've been studying Savannah Sparrows for a decade, I can't tell my animal from the next.

But these are sounds that I created on my computer. They have unique elements like this U-shaped introductory note, or these lightning-wool-shaped introductory notes, or this unusual terminal syllable. These are notes recorded from savannah sparrows, from this species, but from the opposite coast, from the west coast, from Alaska, the British Columbia down to Oregon.

These are sounds 3,000 kilometers away from our island, and they're sounds that we have never recorded since the 1960s in our study population. So there's species typical elements, but elements that are distinctive, they're like acoustic fingerprints, that if any of the young birds was to learn a song from one of our simulated vocal tutors, we would be able to trace it back to one of those loudspeakers and figure out when and where the animal learned that particular sound. So I used this experimental protocol, a loudspeaker simulating an animal with these slightly weird sounds. ...to play sounds with the young birds on the island from the time they hatched from their nest in June until they left for migration.

Then I researched here, oncology, stuff like that. Then I returned there when the young males were coming back from migration, keeping the speakers going. They arrived around April 15th, and we basically get there as exams had ended, and play again until such time that the young females arrived.

paired up and every bird was in a pair and then the one cycle of the experiment was complete. We were broadcasting these sounds in their youth and their early adulthood in the following spring in order to understand when they were learning to sing. Then all we had to do was chase the animals around either with a directional microphone like the one in the jet left or with an omnidirectional microphone in the jet right to figure out which songs they all sang.

Did they sing a typical song? like would have happened on Tent Island before we started this experiment, or might some of the young animals learn a song that matches one of these simulated tutors. On the outlying Tarsus Island, where these 10,000 gulls are, if you set foot, you'll have a crowd of like 100 massive 1-meter-wing span herring gulls dive-falling. screaming at the top of their lungs, and so you can't get any good recordings of Savannah Sparrows.

So we would walk into an area, hammer a stake into the ground, put this up, all the while protecting our head, and then we would run away, and about two minutes later the gulls calm down, and it records for 24 hours. And there's some people in this room who are part of our research lab, and we're scanning through those recordings to try and find which kinds of songs are detected in these long recorders, because we can't be there in person to collect the recording. We have to use these automated reporters. Whichever approach we use, we sample the voice of every animal on the island all year long.

And we use this experiment to test a particular hypothesis. The science class, we've got a book that's been written by hypothesis, right? We could define the vocal learning hypothesis as the idea that wild animals learn songs while listening to conspecific tutors. This is an idea that's been clearly demonstrated for laboratory-reared zebra finches.

but has never been evaluated using an experiment in wild birds until we started this work. So it was pretty risky work to be honest with you. It took like years to design the speakers, to design the sounds, to log everything to this island in the middle of the ocean, to play back sounds, so it took a long time. And then it was risky because if they ignored The speakers would be nothing to tell you about. So I'm kind of revealing my hand here.

There would be no story to tell, no paper to publish. It wouldn't really yield any insight into vocal learning. But we really thought, based on what we read from laboratory animals, that there was a chance that it would. The other missing part of it is there's so many live animals on the island that they could learn from. In the lab, you can have a nestling zebra finch, not hear any nails, and you just have your speakers, and you really stack the deck.

that that young animal is going to learn the song you play, but in the wild there's lots of other animals that they could learn from, real live birds that they could interact with. In fact, one of my colleagues wrote about this bird and said, if you'd asked me in advance, I would have said metal experiment with ways to fail, because he thought that they were all going to learn from the island, the live birds of God. But, you know, screw you, friend.

One of the great mornings of my recorded working life was the day that this bird showed up. The lower spectrograms from a bird, light blue, black, light blue. L-B-L, which is a multiple, so we just call him Little Bill.

And Little Bill shows up, opens his beak, and sings this song. This is a near perfect match with stimulus 7, which is an upper spectrum. So use those colored bars to underline sections of the stimulus that you can see little Bill picked up. He had learned this song almost identically to the stimulus.

Let's look at another bird a couple of days later. Yellow yellow like blue shows up singing this song. which is like a perfect match to a different stimulus stimulus then so again these sounds are so fast i can't really tell the difference between them but when you look at the spectrograms you can see the difference from the light left and right side and you can see how these young animals at the bottom have learned song that is a perfect match with some of our experimental tutor songs people we all want to say yes you're maybe like blue black seeing this song which is closest to stimulus nine. Sure he sassed one note instead of making this note going he did this kind of thing but otherwise he's got this he's got these repeated notes here he's got this up slurred bit and this down slurred bit and those elements are all different from the other sounds that we produce and they're all different from the birds that live on the island. All three of these animals and learned their sounds from a loudspeaker that was simulating a vocal tutor.

Over the course of five repeats of this experiment, as you build an impressive sample size just like you'll be doing in your independent project in this course, we found 30 young birds that produced songs that matched the stimulus. And that was the song they learned, and each day they learned one song, they sang it for the rest of their lives, providing us with unequivocal support for the vocal learning hypothesis. These animals then learned their songs, from sounds that they heard early in their life.

There can obviously be no genetic contribution between the loudspeaker and these young animals. These are experimentally created sounds, but the young animals have learned them during the first year of their life. And so we can take a book like our ecology text, we don't have to throw it away. These ideas that we held to be true from laboratory studies hold up under the magnifying glass of the experiment in wild animals.

which is how good science works. You come up with hypotheses, you subject them to correlational studies, experimental studies, testing those ideas again and again in order to gain a deeper appreciation for things like the behavioral ecology and the adaptive significance of different behaviors. All right, I want to tell you a few little anecdotes before I tell you about a couple of other hypotheses we tested with this experiment.

There were four birds who learned songs from other subjects, so here's an example. Stimulus 1 was picked up in a first generation bird at this weird terminal section that I've underlined in blue and as soon as the bird learned one of our songs we stopped that speaker we never played that song again. A couple years later a second generation of bird learned that unique element from the first generation bird and that's what states we're at right now. We have these novel elements like little stones in a pond dropped into this wild population. and we're watching them ripple through subsequent generations.

That's one of our ongoing areas of investigation in this study. Here's three other birds, four in total, where we have stimulus being learned by a third generation of bird, then we stop the stimulus, and then that bird is talking unusual elements that I created on that computer into a second generation of bird. And we'll go back this spring.

Sarah Daube is your GA for some of you. Sarah and I will go back and see if there's any third generation birds this year. Four birds sang songs that were great matches. Here's an example. The bird is, oh I don't have his, oh there he is, blue, orange, green.

His first song is a perfect match with one of our singly. He sang it for the first couple of weeks after he arrived from migration. And then he threw it away, and instead, his final song was an island typical song, unlike any of our singly. So that bird, the song number three, others like him.

These birds clearly could sing one of the songs we had played, but they chose not to. So they threw that away after the first couple of weeks and for the rest of their life they committed to their one song, a song that was like a typical island song. So something weird is going on just after they arrived from migration.

Now I bet a question that's at the front of your mind is how bad did you screw these birds up, Memal? How did these animals live with these unusual sounds? So I was interested in that question.

I'm certainly hopeful that I didn't disadvantage any animal I've ever wished to do that. And we did find that all of these experimental birds defended a territory with their song like lots of them, and attracted mates like lots of them. They showed similar patterns of longevity. So here we've got all the animals that learn the experimental songs versus animals that learn typical songs from the island and there's no statistical difference between their longevity. If anything, experimental birds live slightly longer.

So we can't find any disadvantage to them. I think we had taught them unusual accents, but they're still capable of engaging in meaningful conversations with the other animals around them. Like if someone showed up here speaking with a Texas accent or a French accent, but in English, we would still realize that we're speaking the same words. So they're still capable of being understood, even though they have these idiosyncratic elements to their song. Was that a question on your mind?

I don't know. I better open the floor for a question or a Q&A before I tell you a couple of other hypotheses we tested with this external. What questions have you got about this study, this behavioral ecology study of Spanish-German someone?

You have zero questions. Well, that means I've done a really good job here. All sounds clean.

Yes, Paige, thank you for asking a question. So, first, you said you had a I love your question, Paige. You're asking about that period after the very young animal flown to Tennessee come back in those first weeks of life we have a little bit of evidence that they learned multiple songs it's like if all of a sudden as soon as you reach puberty you can speak Italian French and English and then you threw the Italian and the French way and just committed to English that seems to be what's happening and I've got some slides to show you about that time period in their life because I was very interested in that question too after we got these first statement it's a great question I'll probably a little more Alright, well let me move right forward then. So, I've described for you a model of vocal learning that originated in the lab and that we're testing in our field-based studies, where vocal learning begins with the sensory phase, often a silent period associated with migration, the sensory motor phase, or the babbling phase for humans, and then crystallization, where they commit to the adult sound. Because of those results that interested me, and Paige at least, I became interested in what's going on in those final days before they commit to their adult song.

We know from lab studies that animals'brains are really open systems up to a point, and then they don't keep growing nerves. And the same thing happens for you and I. That's why language acquisition is quite easy early in our lives, but becomes much more difficult after puberty.

Our ability to recruit new neural connections into the language centers of our brain becomes limited by physiological changes as we age. But what's happening at the beginning of that, during the sensory motor phase? I got really interested at that time of year to think about which sounds are important, and whether that time of year at the onset of their first breeding attempt, where a few birds are singing more songs than we expect, to figure out what's going on there. And so I came up with a hypothesis, the second hypothesis of the work that I'm describing for you today, that animals will learn songs that they heard both early in their life. six months ago when they were born on this island, and then heard again at the onset of their first breeding season.

This hypothesis came out of some observations of other species of sparrow where people suggested there might be a little bit of sensitivity in their brains right at that stage at the onset of their first breeding period. And that's what motivated this idea that they might preferentially learn sounds or retain sounds that they were re-exposed to. And if you think about an animal born hearing all these noises, flying half the world away, coming back, then is the moment of truth.

If this sound is important in attracting mates and defending your territory, it's that first breathing period where it's showing up going, well, let's honor the other animals around your singing to try and attract mates and defend territories. If you can fit in in that environment by changing which sounds you're re-exposed to there, that can be a real advantage to you. If you learn those three languages and all of a sudden you end up in Italy. Having that Italian in there could be the thing that sets you on track to commit to that particular language, if we're going to draw an analogy to humans. To test this hypothesis, during three cycles of the experiment, I changed when different sounds were made.

Some of the sounds I broadcast only in the needle summer, for the first three months of when young animals were born. Another third of the sounds I broadcast never playing them in the summer, but instead only playing them in their first breeding spring, when they're eight, nine months old. And then the third category of sound, the sound that I put back in both periods, in their natal summer and their first breeding spring.

Which category of sounds do we expect to be learned if this re-exposure hypothesis holds any weight? Got my answer? Two? The summer and spring, you got it. If it's hearing it here, and then being re-exposed to it later in spring, it's this third category of sounds that we would expect to be a winner.

Now, these sounds, I had the same number of sounds in each group. They were controlled for how long they were played, their amplitude. Every other feature was the exact same, except what stage in life that the young animal heard. So here are the results.

The winner overall, Tina, you'll be happy to know, is the spring and summer sounds. Overwhelmingly, of the 21 birds in this part, 90% of the 21 animals learned sounds that they had heard in their youth, they flu-sucked, and then they heard it again when they arrived from migration. This offers a strong support for that big exposure hypothesis idea that appears to be important to hearing the song again and retaining it. Now, two birds, 10%, learned songs they had only heard in their youth, And then they didn't hear again when they arrived for migration, because we weren't playing it.

So you don't have to hear it again at the start of your first breeding spray. These two clearly didn't need to. They sang a song that they'd only heard in their navel summer. They have no bird, zero percent, ever, we never had any evidence of any bird being able to produce a sound that hadn't heard in his navel summer, only after it had returned from migration. And this suggests that these animals have to hear the sound in the first three months of their life, or they're never going to learn it.

So, raise your children is the moral story of humans, right? They have to have that exposure, and they're laying down lots of information in their brains, but then that information is refined based on whether they hear it again or not. And if they hear it again, they're more likely, most likely to choose that song to retain into adulthood.

This offers a strong support for the idea that animals retain sounds that they hear again following their first migration. Strong support for the re-exposure hypothesis. We found that, as we got interested in this time period, the first weeks following northward migration, a lot of birds sing multiple songs.

So here's a bird singing English, French, and Italian. He sang song one a bunch, then two, then three, then two, then three, then one, switching back and forth, but only for a couple of weeks. Then he threw them all away, and he kept which one?

He kept song one. I can see that chip and that dash there. That's quite different from these others. So this guy had three songs in his repertoire, but threw them all away in favor of one. Lots of birds did this.

And we call this behavior overproduction. Again, to return to my human analogy, it's like a young teenager who's fluent in multiple languages but throws all of them away when they start getting ready to really hit puberty in favor of just one language. They're singing three, two different songs, but jettisoning all but one.

And this is a phenomenon known as overproduction. It's like exhibiting a larger number of... It's like having a massive vocabulary when you're 12, and then you go to a normal vocabulary when you turn 13. That's the kind of thing that we see happening in the first weeks of spring for these animals. Interestingly, if they live two or three or four years, they don't do this in any future springs.

Only in their first spring do they exhibit overproduction. Now, some work on a different species of sparrow in California has found the same thing. They overproduce and undergo a period of attrition.

Attrition just means getting rid of some things down to their normal repertoire size. In Spanish, that's just one song. And so authors out there came up with this idea of selective attrition.

Behavioral ecologists were interested in what's the selective advantage of a behavior. Is there a selective force driving them to choose one of the songs if they overproduce and then choose one of those songs? So to phrase this as a hypothesis, and my final hypothesis for the day, is the selective attrition hypothesis that after animals produce multiple songs in their first mating spring, they will retain songs that match the songs they hear around them. This is an idea that grew out of the exposure hypothesis. So, we recorded lots of birds.

Here's the example. His name in the band are Split, Split Green, and the Split band is just half white and half black. So he split Split Green, and Split Split Green sang two songs, switching back and forth between them, until he threw one away.

Which one did he keep? Song one or song two? You should be able to tell by looking at the spectre. Good, good. Come on.

Thank you, thank you. Chloe? Song one.

Yeah, so we compared his song one to all of his neighbors. This guy, he was a young male. showing up, started the territory, and he had four other males singing in territories around him.

Here's their songs. And using software in our lab over in the biology building, we compared his song one numerically to all of the songs of his neighbors. These are adult neighbors, so they only have one song in their repertoire. And then low number represents a very similar song. You see how similar split split rain song one is to blue orange green here?

We've got that dash, which is quite different from like pew-poo, or like cha-cha. So this animal has a very low, a very similar song and a low acoustic similarity score. We can do that same thing for a second song, comparing song two acoustically to each one of his neighbors'songs.

And what we found is that the song he retained was the song that had the best match with his neighbors. We repeated this analysis with 27 different young people, and in every case they're keeping the song that is the closest match with one of the animals around. Birds retain songs that are in their mind from the first three months of their life, six and eight months ago, and they're listening to the animals around them and using that information to guide the process of attrition. It is a selective process. They are selecting the song that matches their neighbors, offering us support for the third and final hypothesis that I described to you today.

Support for the idea that attrition... overproduction of polypantrogen gives these animals the ability to speak many languages and find the one that is the most effective communication signal with animals around them. In this paper, we took it a little further. Here on the x-axis we have the acoustic similarity scores, where a very similar song would be on the left side of the x-axis, and a very dissimilar song would be on the right side of the right axis, and we compared that.

Animals who really fit in acoustically with their neighbors, versus males who sound really different from their neighbors, we compare this to how many fights they got. That's our y-axis here, which is a measure of aggression. And you can see that when males produce songs that are good matches with their neighbors, the left side, they end up in fewer aggressive encounters with their neighbors. So there is our adaptive significance of this program, of having your mind...

be ready to hear lots of song in your youth, you have to go to silent period, you fly south for the winter, then you come back, you listen to the sounds around you, you're overproducing, you're honing in on the song that is the best match to the neighbors around you. And when you do that, you end up with this resource defense mating signal that incites the fewest fights with your neighbors. There is a direct advantage to engaging in this behavior.

This is me pulling behavioral energy strongly into the... That's from this lecture, right? We have come to understand the value of what might at first seem like a fanciful behavior, trying to figure out why animals sound the way they do, but we find that there's a real survival advantage here. Fewer fights with your neighbors if you follow this particular learning program. In other words, by retaining similar songs to their neighbors, birds end up experiencing lower levels of territorial aggression.

during the rainy period. That means energy savings. That means fewer injuries from the fights with your territorial leavers.

The final point I want to make is that all of this work we've done actually scales up at the population level to show us something about how the entire population of San Amsperas on Kent Island sounds. So each year for the last 10 years I set up with posts and 16 of these recorders into gull land. Lots of gulls swirling around me and it pooped on me. It's the worst, especially because there's no plumbing on this island.

It's a bucket shower. Anyway, that's not the point. We traveled around to each one of these sites on our main island. Each black dot is about 50 meters from the nearest black dot and that's a site in the meadows.

The dark green is the forest, the light green is the meadows. And every year we set up a recorder 24 hours in order to survey every bird on the island. At the beginning it was in order to find those birds who might be vocal learners. But as we went forward, we looked at the island's typical songs, not our experimental songs, but the typical songs of the island, and we found there's a couple of really common themes. I've color-coded them here.

There's the yellow theme, the red theme, the purple theme, the blue theme, and each dot on the right-hand side is a different bird singing a different theme. It's a lot to take in, so let me hone in on the most northerly part of our study site, Hay Island, and we'll look at just one. Each dot is a male, the color shows you which island typical song he was singing, and the dots shows the proximal territory boundaries. Now what do you see right away here? They end up...

go ahead Chloe. Brilliantly put, Chloe. They're attracting other animals, or better than attracting, they're ending up in these little clumps of yellow, which is one of the things you know, and they end up in these pockets of similar sounding animals. Yeah, we've got a big pocket of yellow, a little pocket of yellow on the other side of the island, a pocket of blue, poor purpley up here, he doesn't have any neighbors, maybe he didn't care, a pocket of purple down here. This behavior of learning can be reduced, overproducing at the onset of adulthood.

Undergoing selective attrition based on what you hear is the mechanism that drives a dialect. They end up in pockets of similar sounding animals because of this individual level behavior. And so we see structure at the level of the whole population in terms of who sounds like who, because of the individual things that these animals are doing to maximize their chances of survival.

I'm going to skip two slides and go to my conclusions. I have today shown you work out of our research lab that I'm really proud of that I've worked on over the last decade. This is experimental evidence that wild birds learn to sing based on sounds that they have heard early in their life. We found that birds preferentially learn songs that they hear early in life but then hear again when they are young adults returning from migration. And at that point, as they arrive in their first spring...

They are overproducing, producing a larger than normal number of sounds and undergoing a process of attrition. It is selective attrition because they are choosing from the library sounds that they have laid down as memories of their youth, the sounds that are the best match of their adult environment and using those sounds to interact with other males and other females. And the ones who learn the most similar songs end up with fewer aggressive encounters with their neighbors.

There's no part of the textbook you can read about this, but I want you, I've spent time on it, so I think it's fair grounds for next Thursday's exam. If you want to read the specific details, I wrote this paper and I try to write in an accessible way. not always writing in passive voice, but active voice, the same way we'd like to teach you to write for your independent project in this course. If you go on my website, you can find, if I was to point you to a single paper that best summarizes the work I've described today, it's this one on my website. Current biology is the journalist called Wild Birds Learn Songs from Experimental Vocal Tutors.

Now this work that I've done, I've told you that I'm going to make you work with a partner. in your independent project here. This work that I've done has many, many partners. First of all, this work was funded by the Natural Science and Engineering Research Council of Canada. I have four collaborators, profs at U Windsor, University of Guelph, and Williams College in the United States, and many student collaborators, Sarah Dovni, many of you know.

Abby Hensel I met when she took ecology about 10 years ago and lots of students have been involved in this work lots of people have been involved in the logistics and the field assistance and then people in my lab some of whom are here today are playing a heavy role I need to update this slide to add our new cohort of researchers a lot of people helping to scan through those recordings in our study of vocal learning and wild birds.

Transcript for:Exploring Behavioral Ecology and Vocal Learning

Transcript for:
Exploring Behavioral Ecology and Vocal Learning