Thumbnail image: Kevin McGowan | Macaulay Library

[Lisa Kopp] Welcome to today’s webinar from the Cornell Lab of Ornithology. Today we’re going to be, like I said, doing our best to answer your bird-related questions, as they relate especially to spring migration, which is underway at least where we are located, here in Ithaca, New York. My name is Lisa Kopp. I’m on the visitor center team at the Lab of Ornithology, and I will be facilitating today’s conversation. Joining us is Kevin McGowan. Thank you for joining us, Kevin. Well, thanks again for joining.

And we will talk with Kevin in just a few minutes because I know he’s the reason you all are here. I do want to get through a few quick announcements, though. As I mentioned, today’s webinar is hosted from Ithaca, New York. And so, I want to read a statement acknowledging the Indigenous people as the original inhabitants of this area.

Cornell University is located on the traditional homelands of the Gayogoho:no, the Cayuga Nation. The Gayogoho:no are members of the Haudenosaunee Confederacy, an alliance of six sovereign nations with a historic and contemporary presence on this land. The Confederacy precedes the establishment of Cornell University, New York state, and the United States of America. We acknowledge the painful history of Gayogoho:no dispossession and honor the ongoing connection of Gayogoho:no people, past and present, to these lands and waters.

And for those of you who aren’t familiar with the Cornell Lab of Ornithology, we are home to a community of researchers and supporters from all around the world who appreciate birds, and the integral role that they play in our ecosystems. Our mission is to advance leading-edge research, education, and citizen science that helps solve pressing conservation challenges.

So a couple of quick tech notes for our audience. We have closed captioning. If you are watching over Zoom can turn on or off captions at the bottom of your Zoom screen by clicking the three dots. And there will be an option to either show or hide subtitles. For those of you who are also on Zoom, we’re going to be using the Q&A function today as I see some of you already are. That is where you can submit questions for Kevin.

We’ll be answering some of those questions live, but we will also be typing in responses, which you’ll be able to see in the answered column. We have wonderful colleagues behind the scenes who are helping us today with that. And we also got so many amazing questions submitted to us when you all registered, so we are going to do our best to take from all of the places that you all have shared your questions with us and get as many of those answers as possible.

That being said, we are only going to be using the chat for Zoom technical assistance. So, if you have issues with your sound or your video or something’s happening, we always recommend restarting your Zoom as the first step. Things seem to be working OK on our end, but if you need help, we again, have wonderful folks behind the scenes who can offer some guidance.

And we’re also streaming live to Facebook. So, hello all of you watching us on Facebook. And while there isn’t an official Q&A or chat function on Facebook– if you would like to submit some questions you can use the comment section, and a colleague will help relay those to us as we are able to answer them.

OK, so let’s get started. So I did want to mention quickly what today is going to be like. It’s going to be a little different from any of the webinars that you may have attended in the past. This is the third of a series of webinars that’s meant to help get you ready for spring birding. So the first that we did was about eBird, the second was about Merlin, our bird ID app, and today is about ornithology.

So as I said, we’re going to be answering questions that you pre-submitted, questions that you’re asking live, and hopefully be able to get some of your burning bird-related questions answered, as we get into this exciting time of year. So to start, Kevin, thank you again for being with us today. Could you tell a little bit about who you are and what you do before we pepper you with questions?

[Kevin McGowan] Sure, sure. I’m a professional ornithologist and educator. I work in Bird Academy. I write online bird courses and we’ve been doing outreach ornithology for a very long time. We started with courses that were highest technology of the day, the US Postal Service back in the 70s with a correspondence course. And then we’ve changed and gone online. We’ve done– did a bunch of webinars and we’re now doing online courses that are interactive, so that you can go in at any time and do it at your own pace.

And I personally have been interested in birds since I was a little kid. I’ve been an active birder since junior high, and the same. I do this as a profession too. I’ve been studying individually marked American Crows in Ithaca for 34 years now. And so, I do the science, and I and I enjoy the birds. I’m also a total bird nut. I have lists and chase things and all of that kind of stuff. I have a fairly broad interest in ornithology, everything from bird ID, bird migration, bird movements, to behavioral ecology, which is the main stuff I do what– how birds interact in families and things like that.

But I also am interested in pretty much everything from anatomy and paleontology to ecology and evolution. So– and I– one of the reasons I’m here is I have a great mind for trivia, and I know a lot of little things about a lot of birds. So let’s get at it and we can have fun.

[Lisa Kopp] Great. Well, we get– we actually got one question. What is ornithology? Could you start out with the basics for us?

[Kevin McGowan] Sure. Ornithology just means the study of birds, and it can be anything from genetics to behavior to populations and things like that. So anything, any kind of science that you do, organize the data gathering and that kind of thing, trying to find out new things about birds. That’s what ornithology is all about. So, some of it– so some ornithologists that I know are excellent ornithologists and they aren’t birders at all. They don’t know what the birds are in their own backyard. But then there are some of us who are still crazy, and it’s like we think birds all day and then we go home and think birds all evening and over the weekends just to keep going. So it can be a wide range of things.

[Lisa Kopp] Well thank you. And I speaking to that, this time of year is especially exciting for ornithologists and bird love– non-ornithologist bird lovers. So, and that’s sort of why we came up with this series of webinars, to help people get ready to watch birds this time of year. So we had a really great question that Desmond M. submitted in advance that was about spring migration. And it sounds like they live in a similar region to Ithaca, New York, sort of in the upper Northeast, and they’re interested in understanding why there are birds that stay in some of these cold climates all winter long. And that’s sort of a great intro– or like a nice gateway to talking about migration. So could you give us a little bit of insight on sort of just the basics of migration?

[Kevin McGowan] Sure, you bet. And I– living in upstate New York sometimes you wonder why is anybody here in the winter. I mean I love winter. Used to. But– so the main thing about migration is it’s generally tied to food. And it can be birds that are going someplace to take advantage of an abundant resource, and then leaving when that resource is over.

That’s so we can think of a lot of the birds that go up to the high Arctic is that there’s a very brief window of time in the high Arctic where birds can get up there and find tons of food, and feed their babies, and then get out as fast as they can. But other birds actually stay in the Arctic. There are a few birds that winter up in the high Arctic because they can find enough food to eat. So they don’t need to move.

Most birds probably don’t move for temperature reasons. That– some of them do now. I mean there are some they probably couldn’t exist. If you gave them extra food just because they’re in– some of the tropical birds don’t handle cold very well, but most birds do. And, in fact, there are tiny birds, little chickadees and Golden-crowned Kinglets– they weigh about as much as a nickel. They stay put in the winter, at least in some very cold places up here, as well. And the thing is they’ve got so much fluff on them that– think about it– all these birds are flying around with little– in little down sleeping bags, right? And so, what they do is they fluff up and it can hold enough energy, enough heat in there.

If they can find food, and that’s the big deal, because a lot of birds that go to the tropics– if you think of things like tanagers and fly catchers and warblers– they’re actually feeding on insects, mostly flying insects– like the flycatcher specialized in flying insects. And if you’re specialized in the food that you eat and then suddenly that food is gone you got to get out of there and go somewhere else.

But there are other birds like the chickadees and the kinglets that also eat insects, but they’re finding– it’s hard to believe that they can find it– but they’re finding overwintering larvae, a lot of insect eggs. Think about that. I’ve never seen an insect egg, I don’t think, because they’re so tiny, but they’re– like other eggs– they’re full of nutrients. And so they can actually find them in the crevices and in the bark of the trees and places like that so that– such that they can get enough food to last through the winter. And so they can stay place– stay in place.

And a lot of birds move– Also there are three things that you have to do in a bird’s life that you think about as important. One is to raise young, the other is to survive the rest of the year, and the third is to change all of your plumage. So regrow all of your feathers, because feathers are dead things and they wear out. They’re not constantly being replenished they just, are done, and then you have to change. And there are birds that will migrate places to do the molt after.

So they breed, and then they go somewhere else to molt, because they need– what you need when you’re breeding is food for the babies. And when you molt you need to have food that’ll help you make new feathers, and then the rest of the year you can make it on other foods that may be more abundant somewhere else. So it’s an interesting thing.

And birds– birds migrate all over the world, but sometimes it’s from north to south. Down in Argentina it’s south to north. But also, there are migrations in the mountains where some birds will come down the lower in the mountains during the winter too. So there are a lot of things that birds do to find ways to live in all kinds of places, but maybe not all the time. So it’s really quite remarkable how widely birds get distributed on the earth, and it’s pretty cool.

[Lisa Kopp] It’s so interesting to hear that migration is far less about temperature, and far more about food. So I think we all have this perception especially in these cold climates of these tiny little birds freezing in winter nights. But if they’re able to sustain themselves, they’re likely warm enough at night, right?

[Kevin McGowan] And, again, there are different strategies. There are a few that nest in– overwinter in cavities. Most don’t, and yeah, it’s interesting to think about these little guys. Again, the kinglets– sometimes the kinglets will actually sit on a perch together. Four of them in a row kind of thing which helps a little bit with keeping warm. But they are sleeping on branches, Like they’re– they’re not in a little nest– they’re just sitting on a tree branch somewhere, often under cover. I’ve got some spruces in front of my house that the juncos seem to like to roost in at night all winter long. And yeah, as long as they can find food, they can find a way to keep warm.

[Lisa Kopp] Are there particular kinds of birds that tend to– Rob N. Asked this question. Are there certain kinds of birds, like songbirds or raptors, that tend to stay in certain territories or migrate more, or is it really just dependent on the bird itself?

[Kevin McGowan] Yeah, it’s a wide variety of birds that stay put. And some birds do. They– I think the part of this question was about having a territory all year long, and a lot of birds stay more or less, put. But they aren’t in territories. That’s an interesting thing too. Again, this stuff gets more exciting, more complicated, the more you look at it like American Crows, the ones that I follow.

They keep a permanent territory all year round. Now remember a territory is a separate thing. It’s not just where they live. A territory is a defended space. And typically, in the breeding season things like robins will declare their territory, and no other robins allowed to come on there except their mate. And that– but with robins, as soon as they’re done breeding then they forget about the territory and they all join up together and spend the winter in these giant flocks.

So– and they move around. Now they could stay in the same place or they could go– robins tend to go further south, into the southeastern– southern part of the United States to winter. But there are other birds like Black-capped Chickadees and Blue Jays that, again, are pretty territorial during the breeding season. But then as soon as they’re done, they stay together with their mates, but they– but they all cluster in a group and wander around kind of a group territory.

So again, it’s seasonal, and you don’t always want the same thing every day of the year. So it’s interesting. And in some of these other birds are– they’re moving around a lot. And some birds kind of wander and other ones go to specific places for wintering. It’s a mixed bag and there’s an awful lot of interesting stories to be told.

[Lisa Kopp] Do you have any– So you mentioned many birds– if birds are staying put– they’re just roosting up in a tree, sleeping overnight. But I also know that much of migration actually happens at night, right? Is there– this is a softball question because I know the answer to it, but we had some questions pre-submitted, Wendy K., and I’m seeing others in the Q&A, talking about how people can find out about when major migrations are happening. Do you want to chat a little bit about BirdCast?

[Kevin McGowan] You betcha. Yes, migration is a fascinating thing. Some birds like waterfowl migrate a lot during the day, and you can see it. But most of the major migration going on, especially for songbirds, is at night. And there are ways that we can track some of this stuff. That– again, it’s not just every bird moving all the time. It’s like birds getting up at the– as soon as the sun goes down and migrating.

And we at the Lab have an immense project– a project that helps to follow migration.

I would say normally– if you’d say, well, what makes a good migratory day? Well, you follow the weather. You have to watch the weather, because the birds tend to go on favorable winds. They like to surf, basically, get a boost as much as they can so they don’t have to power flight the whole way. But– and so they’re watching the weather. If the winds are from the north, they’re not going to fly north, necessarily, until they get some south winds.

Now we have a project called BirdCast that is with our radar ornithology group here, that’s doing a lot of research on tracking migration and looking at big picture things of how many birds are in the air, and are there more or fewer than there were 10 years ago, and that kind of stuff. Fascinating stuff. But they have a website called BirdCast. It’s And you can go and you can find a map for your home county and see what the forecast is for the migration that night.

And it uses these color-coded maps, and you can see where the pockets of migration is forecast to be. And you can also look at real time images of how many birds are in the air at that moment. It’s really fascinating, just fascinating. And I encourage everybody who really wants to know to go look at that, and have that sort of on your desktop.

Every now and then check in to see, oh is it going to be a big push tonight? And then I’ll need to get up early and go out birding when the warblers are dropping down because it’s just a monstrous move. So– and that’s really fun. It’s amazing technology to think about. It’s just mind boggling that they can come up with the forecast and things as accurately as they do.

[Lisa Kopp] Yeah, it really is fascinating, and I’ll make a quick plug. We’ve put the link to the BirdCast website in the chat, but we are also hosting a webinar in just over a month with the BirdCast team because they just rolled out a new dashboard that makes it even easier to understand when there might be big migration movements in your area. And we want to be able to showcase that incredible work.

So we’re getting lots of questions about nighttime activities related to birds. So the obvious question is if they’re migrating at night, are they sleeping during the day? And, and– or are we thinking about this within the construct of like, human sleep, like what are the differences between what a bird needs to sleep in order to migrate or to not migrate? And how does that affect their daytime and nighttime activities?

[Kevin McGowan] Yeah, it’s an interesting question and it’s– say– there are a couple of different ways that birds can do things. One is that some of them do sleep like you see ducks sleeping all the time. They may have been moving during the nighttime as well. And so, they do– some birds do sleep a little bit more during the day. But we’ve also discovered that some birds have a different– birds have different brains than humans.

So we’ve got two sides of our brains, right? And you talk about the left side right side well the two sides of our brains are actually connected– have a physical connection between it called the corpus callosum that sends signals from one hemisphere to the other. Birds don’t have that. They have two separate brains that don’t necessarily communicate all the time. They have separate functions.

And so, what birds can do is they can sleep one side of their brain at a time and keep the other brain awake to keep everything moving. And that’s what we think a lot of birds do is that they sleep half their brain while they’re flying at night. And then switch to the other half and then sleep it while the other one’s still conscious. It’s amazing to think about.

And, I, you know, I’m– it’s– birds do sleep both brains at the same time. You can see them do that, but they also can do this other. They could use it for, probably for migration. Also, for birds like ducks and things like that they’re actually keeping alert. And so, you’ll see them open one eye a lot of the time then. So they’re using that, arousing the one side of the brain but keeping the other one sleeping so it gets all the benefits of sleep.

[Lisa Kopp] Wow.

[Kevin McGowan] Which is just wild.

[Lisa Kopp] And if birds are moving so much at night, we’re getting some questions about whether the full moon has any effect, or if moonlight is how they’re navigating. Could you tell us a little bit about how birds, first of all, figure out where they’re going in the dark of night, but also communicate if they’re migrating in flocks at night?

[Kevin McGowan] Sure, the communication is easy. They’re actually talking to each other. So the birds, migratory songbirds, give constant little chips, call notes, that are different than what they make during the day usually. And so, you can hear– you can go out on a still night in migration and hear them flying overhead. You can hear warblers and sparrows chipping as they go by. And so, they’re kind of, I think, using that to keep track of where everybody is.

You don’t want to bump into anybody, and if you’re traveling with the group the same species, then you might be honing in on them to keep them together like that. That’s an easy one. The– how do they see where they’re going and then know all that stuff that’s harder, and it’s a combination of things. One was a– Steve Emlen who was a former professor and a professor emeritus here at Cornell University– he found out that birds were using the stars. And he actually raised some in a planetarium and raised them such that the stars were off.

And they would orient to– what he found is that they basically watched the rotation of the stars through the sky, and can focus on where they know where north is. They know which way north is by the rotation of the stars. And they– yeah, it’s astounding that they learn that, as somewhere as they’re young. And he messed these birds up, so that they thought something else was the Pole Star instead of Polaris, and then when he let them go, or had– was seeing how they were orienting within the planetarium they followed that route, the route that they had seen with the stars.

And so, what’s interesting is that they’re using stars to know which way to go. But they also– I mean sure some of them moonlight can be good. But a lot of these birds are flying pretty high and don’t need to be watching to bump into obstacles and things like that, which is what moonlight’s best for.

But they also have some sort of a magnetic sense that they can sense the magnetic fields of the Earth, and that gives them a sense of sort of left and right, as well as north and south, because it– and that turns out is– somewhere in their eyes there’s a– some pigments– I forget the name of them right off- that are– gets into weird science quantum mechanics where they have to have a little bit of light that bumps the electrons into a weird state in this, these pigment cells or pigments.

And that then gets them in a quantum state that allows them to detect, to actually see the lines of magnetic force. And so, they have to have a little bit of light, but it’s kind of like, you know how, when you’re in– your eyes are light adapted, I mean dark adapted, and everything you see is like a gray. And then when you you’re using the rod cells in your eyes that are good with low light, and the color cells are sort of turned off because there’s not enough light to stimulate it. But then once there gets to be a certain level of light then your color– you start seeing color again, and because those other cells are turned on. And it’s somewhere right around that rod cone break that the birds can see or not see the lines of magnetic force. It’s really pretty weird.

[Lisa Kopp] It’s incredible, and we’re getting a lot of very accurate comments about how the derogatory term of calling someone a bird brain is absolutely inaccurate, right? Like–

[Kevin McGowan] Birds can do some pretty amazing things. I mean it’s like we know that some birds, like some of the European swifts– they don’t even stop flying. They only stop flying to breed, and they sleep in the air. They migrate– again with that double brain thing– they can still do that. And yeah, they just don’t sit down. Because they don’t need to. It’s really quite amazing. Birds are amazing creatures.

[Lisa Kopp] They are, and it’s a testament to how incredible it is to have so many scientists studying and trying to understand these– all these incredible aspects of their biology. So–

[Kevin McGowan] I just want to say, yes it really is. And that’s one of the fun things to right now we’ve had such a technology boom over the last couple of decades that we’re finding out things that we never had a hope of ever figuring out before, and it’s a really exciting time to be a scientist working on birds. And just amazing when people are coming up with.

[Lisa Kopp] So, as a segue, a lot of what birds do is likely evolutionary, and with that we can talk about nesting, right? And so, I want to transition a little bit to– we’ve got, we’ve got a whole– we’ve got tons of questions. But with this time of year. I want to talk about nesting and nesting success. And so, let’s see we had a question from Thomas M. asking what are the odds if you see a particular male or female bird during the breeding period that though that pair will have a complete or successful nesting cycle which would be incubation, birth, and then a fledgling, you know, being– moving into being a juvenile bird.

[Kevin McGowan] OK. I’m not quite sure which is– the point here is that the probability of those birds breeding at some point or being successful?

[Lisa Kopp] I think being successful. That’s how I interpreted the question.

[Kevin McGowan] So I can answer both sides, which is just to say that not all birds actually get the opportunity to breed. Depending on the species, most of them will try, but sometimes whenever their resources that are limited, some birds don’t get a chance to. And in my American Crows the young birds don’t breed until they’re at least two years old, usually four or five. So there’s a big component of the population that’s not breeding. And with the crows they stay home with their parents and help them raise young.

But for most birds like robins and cardinals and sparrows and things like that, they’re breeding. Everybody tries to breed if they can. As far as the success goes, well this is sort of the bad news. This is the nature, red in tooth and claw kind of thing, that most birds are not successful breeding, period. That– depending on the bird and where they fit in the food chain, most breeding efforts are unsuccessful. So, for example, if you have a nest of eggs of something like a robin or a jay or a sparrow, basically 70% of those nests fail to produce anything.

And so, it’s only a third of the nests out there actually getting young to come out of the nest. And then all those little birds that come out of the nest, basically 90% of those die the first year. And so, there’s this tremendous turnover of birds is just remarkable. But there are enough that do succeed to keep them going, most times. So– but the numbers are really, really harsh.

For our American Crows basically about 50% of the nests succeed, and they have a really– up until West Nile came around– really high fledgling survival rate. About 50% of our kids that we mark we could find alive in there– in the area a year later. And that’s– I mean that’s– half of them die and that’s a really good rate. That’s like high. It’s like really, really good. So there’s a lot of death out there in life. And so, we as people who follow the, sort of to say, the demographics or the numbers of who survives and who don’t, it can be very sobering. We’ll get into this.

[Lisa Kopp] Is there– I mean I guess I could ask the question about your crows. Andy T asked if, specifically songbirds, typically return to the same locations to nest year over year, but hearing you talk about the crows that you study I’m curious if the crows also return to the same nesting locations. And if success is a factor when they’re determining whether to return to the same nesting location?

[Kevin McGowan] Well, that’s an actually– that’s a good question. And the point you just put on it is also an interesting one. It varies with different birds as you say of American Crows here are permanently territorial. They don’t migrate. There’s some wandering of the non-breeders, but they don’t– but something like robins, there, in general, except for odd species that sort of are semi-nomadic or whatever, a lot of birds– most birds– come back to where they were raised. Well, male birds come back to where they were raised, and somewhere nearby.

And often birds that have been successful breeders will return to the exact same nest– nesting area that they were in the past. And if they failed, then yes, we get to see more birds not come back. And so, some of these things are where pairs will come back and meet up again and re-nest with each other, but we find that if they fail– if the nest fails, then they’re less likely to get back together and do it again. So I think that was the main point of the–

We know some birds go long distances and come right back to where they were. It’s just amazing, but then we don’t know– again, we’re talking about– a bird’s smart. You know, what’s a bird brain? It’s like, well they can fly to Argentina and come back and find the same bush that they nested in last year. We say, no, no, no that’s all instinct, right? It’s not smart. It’s complicated.

But the other thing I want to say is there’s another facet of this, which is do birds reuse their nests or not? And the great majority of birds do not reuse their nests, because for one thing it’s that– Think of it as that a vulnerability to predation, because most of the young songbirds die because something eats them. And if– the way I thought about it, the nest is a very dangerous place to be. In a nest for most birds is only a cup to hold babies, and then you get them out of there as fast as possible, which is sometimes amazingly early, because the deal is that you don’t want to have all your eggs in one basket.

And if there’s a raccoon checking every shrub in its territory, one by one, eventually he’s going to find somebody in there. And so, you don’t want to– you want to get the birds out and you don’t want to go back so that they find the nest, and say oh this is a– missed this nest maybe I’ll get it next time. So that’s why even birds the size of crows generally don’t re-use their nests. They don’t reuse them at all here.

There are some places where the nesting materials and opportunities are somewhat limited and they will do it, say, and I’ve seen nests that have been reused in Seattle, say something like that but around here they don’t. You’ve got to be big to be able to reuse your nest– something like an eagle or a big hawk– that they’re big enough that they can protect their young well enough that they can afford to reuse the nest, but those small birds don’t. Although some birds use other nests like mourning doves love old, old American robin nests. We had a pile of American robin nests on the ledge at the entranceway to the Lab of Ornithology and a couple of years ago I watched mourning doves use the robin nests to pull off I think six different broods of young, because it was just in such a nice safe space.

[Lisa Kopp] Why do some birds nest in cavity spaces and others have sort of the more traditional cup nests that you’re talking about?

[Kevin McGowan] Well again, some of it’s evolutionary history of where they went and started to do things. But the basic idea is that holes are great because they obviously provide protection against the weather, and they’re harder to get into for predators, so generally hole nesting species have higher reproductive success, higher nest success, than do open cups. But there are only so many holes out there, and most birds that aren’t woodpeckers aren’t very good at actually creating their own holes.

Woodpeckers can do it, and they’re greatly appreciated because other birds take over the cavities as well. But they’re limited. And so, there’s always a big competition to try to find a nest hole, and so, sometimes it’s much easier to not get in a fight with a woodpecker or another bird of your same species, and just put them out somewhere easier. And so, it’s a trade off between nest success and availability, because it doesn’t do you any good to be a bird that’s got 100% nest success, if you can only find a hole, but there aren’t any holes to be found.

And so, you get 0% nest success. So again, evolution doesn’t– natural selection doesn’t pick just one path, one way to solve a problem. It’s like which way do you go around a block to get to the opposite corner? Sometimes you go left, sometimes you go right. Some birds go left, some birds go right, and there are many ways to answer an evolutionary question, so to speak. Like how do you– how do you raise enough young to replace yourself in the population. And there are lots of different strategies.

[Lisa Kopp] Related to nesting, but more of the actual early stages of it– Jen I. Asks how long is the gestation of an average bird and, or, how many days from mating until laying an eggs, and does it, vary much between species?

[Kevin McGowan] Well, it varies a lot between species. Generally, it’s related to body size. How many eggs a bird lays, and you know, how big the eggs are going to be. Obviously, it can take longer to produce an egg that is bigger and that egg is going to take longer to develop. So, for in general, for songbird-type things the medium sized to smaller songbirds, the– OK, let me start at the beginning of the chain. The birds copulate. Some of the copulation can be not ready to fertilize yet but to actually get all of the things going.

And this is one of the points of migration I didn’t get to say is that birds’ sex organs typically shrink when they’re not breeding, and then they regrow them when they start to breed. And you can think of that as a way to save weight. If I were a chickadee in breeding season my testes would be like this big and take up half my body– a third of my body cavity. And then they’d be like that in the winter. So it takes time to get all of these things growing.

It takes time for the females to develop enough follicles, enough eggs, to get them all out and birds typically only lay one egg a day. And so, that egg has to be fertilized right before the shell’s put on. And so, there’s a timing issue. So generally, the birds mate the day before a single egg is laid. And so, it’s the songbirds can store sperm and fertilize the eggs at multiple times, but that’s not typical. It’s usually there’s a copulation the day before that fertilizes the egg that comes out later this day, that kind of thing.

[Lisa Kopp] Fast.

[Kevin McGowan] Yeah, it’s fast. And so, then the small songbirds when they’re laying, they usually lay somewhere between two to six eggs, something like that. So it takes them about a week to get the clutch done. They don’t start incubating– most birds don’t start incubating until the last or the next to the last egg, so all of the young will develop at the same rate. And it takes about two weeks for the incubated eggs to hatch, and then the young are in the nest about another two weeks before they get out. And they come out kind of early.

Get something a little bigger like a Blue Jay or Scrub Jay or a Stellar’s Jay. They’re– takes about 18 days to incubate, and another 18 days in the nest before they come out flying.

And some of them don’t come out flying. They come out, again, they’re trying to get out of that nest as fast as possible. And so, birds come out before they can fly very well, and you sometimes find these little fledgling guys on the ground, which is OK. They’re supposed to do that, but people think oh, they’ve fallen from the nest. It’s like they’re trying to get out of the nest, they just fell to the ground. They want to be back in a bush somewhere.

[Lisa Kopp] Wow it’s fascinating, and we could talk about– we could talk about all of these topics for hours on end, but I’m seeing a lot of questions about birdsong. So I wondered if you could talk a little bit about mimicry. I’m seeing a lot of questions about birds– Susan P. asked specifically about robins, whether robins are known to be mimics, and are there other or certain species that are known to be mimics?

[Kevin McGowan] Yeah, mimicry is cool. It’s a very interesting thing, and it’s fun when you find a bird like a Northern Mockingbird. In the United States is the classic mimic that mimics so many things and I’ve sat– there was one at the entrance of the YMCA here, in Ithaca, a couple of years ago, and I sat there and it’s just like, OK that’s 12 different birds that it’s imitating. And so, it’s pretty neat to hear that kind of stuff. American Robins do not do that. I don’t think I’ve ever heard a robin imitate anything. Starlings are great mimics. And so, anything in the mockingbird family– catbirds and thrashers– they do a lot of mimicry.

There are other birds that are a little– do it a little quieter. A Purple Finch is actually an excellent mimic. That they have an interesting song that they always sounds like it’s being shaken out of its way– goes back and forth and back and forth. But they throw in the– especially the little soft songs. They’ll mimic other birds in there too. But of course, the most, probably the best, mimic around the world is the lyre– Australian Lyrebirds that can do that. I remember seeing a nature special where this one was doing– it was at a place where people were photographing a lot, and it did camera shutter noises, like– a logging truck going by, that’s what one of the ones was and one was supposedly a flock of parrots flying up with both their screeches and their wing noise, that they imitated. It’s just really bizarre.

And why do they do it? People might want to know and we don’t really know, but it does seem like there is an advantage for the males that have the largest repertoire of noises that get the girls, more than the ones that have smaller repetoires. Same thing’s true with bird songs just things like Song Sparrows can make some very complex, well, melodies and it turns out the guy that has the most variety in it seems to get the girl first. So it’s mostly, probably sexually selected trait to show off whatever it is that you’re paying attention to your surroundings or something. I don’t know.

But I will say, just the robin isn’t a mimic, but there is a very closely-related bird in South America, the Hauxwell’s Thrush, that is a very good mimic and does a lot of different things, incorporates a ton of different things into its song.

[Lisa Kopp] We had an interesting question about why some bigger birds have very, sort of small, calls and why smaller birds have big calls. Any thoughts on that?

[Kevin McGowan] Yeah, again it’s– I would say, probably sexual selection, to a certain extent, that some birds the voice is an ornament, just the way a plume could be an ornament, or long tail could be an ornament. The vocal stuff is very, definitely– there’s selection to change that. For some birds it’s– Yeah, it’s amazing. Carolina Wren, it’s like this tiny little bird and it just belts out this monstrous song that carries all over, and then it’s just quite remarkable how size doesn’t determine how loud a bird is. There are other things going on there.

[Lisa Kopp] Yeah, and I should mention that if people are interested in improving, or being able to ID bird songs more effectively– last week on Tuesday we had a great conversation with the Merlin bird ID team, and Merlin now has a sound ID feature where you can use your phone to record sounds, and it will ID calls on the spot. And it’s really just like absolutely unbelievable. We’ll put the link to information about that in the chat, but you could watch the archive webinar from last week or just check out Merlin bird ID for some really incredible tools. So, we’re–

[Kevin McGowan] We also have a course in Bird Academy about learning bird ID as well. So it’s just the beginning, how to start to think about it, and to break down bird calls so that you can also take a course on if you want to.

[Lisa Kopp] Great. So we’re getting a lot of questions about bird feeders and feeding birds. And I know that we have– there’s a whole other area of the Lab that specializes in this, which we’ll put some links to but, Kevin, do you want to share just a little bit of information or tips for safely and appropriately feeding birds? And we can make sure to point people to the information where they can get all the details that they’re looking for.

[Kevin McGowan] Yeah, bird feeding is an interesting thing. There are a number of schools of thought on what actually is going on there. You know I have my own personal philosophy about this stuff. And there are other people who love it and people who don’t want you to do it, and all kinds of things like that. The basic bottom line, I think, should be don’t try to supplement the world. It’s like bring birds where you can see them that’s sort of what my– why I feed birds is that I like having the birds up close where I can watch them because I like to watch birds.

And there’s supplemental feeding can help survival of some of the wintering birds for sure. But it isn’t– the birds don’t necessarily get– so they don’t find natural food. And that’s one of the things people say– oh well, if all they’re eating– that chickadee is only eating sunflower seeds that can’t be good for them. But they aren’t just eating sunflower seeds they’re supplementing with sunflower seeds but they’re still finding insect eggs and insect overwintering insects out in their normal areas.

It is, I think, useful to think about what you do when you create a bird feeder, and that is that it is a concentration of birds. It does bring birds together in one place where they’re trying for the same stuff. And that often leads to conflict within the birds. You see a lot of aggression around a bird feeder that you would never see out in the woods. But– so that potential is also there for disease transmission. And so, we recommend cleaning your bird feeders.

FeederWatch has a whole page on how to keep your feeders clean and when you should do it and that kind of thing. But– yeah, I mean I know an awful lot of people that get great joy by having even House Sparrows come to a feeder in their urban lives, because it’s marvelous to watch. And it’s– I think very– it’s a joyful thing for a lot of people. A lot of people found that out over the last two years. It’s like I can’t go anywhere. What can I do? It’s like, oh! Thank you for having a bird feeder.

[Lisa Kopp] Yeah. Bird ID– it’s like it takes a lifetime to be able to ID birds the way that I know you can. And we do have lots of great– The Lab offers all sorts of great resources, courses on Bird Academy, many of which you teach. The Merlin bird ID app is incredible for beginner birders, of course. But we got a really great question from Carol C. who asked, “When watching a bird flitting all around the tree and binoculars, is there a particular order that you check things like facial markings, tail length, bill, chest– when you only have a few minutes or a few seconds to try to ID it. Do you have any suggestions for that kind of quick ID that you’re trying to do, before you can get out your field guide or your Merlin app?

[Kevin McGowan] Yeah, I think the basic thing is to get an overall snapshot of what basic shape the bird is and what highlights stand out to you. If they’re moving quickly enough and you’re not experienced, you’re not going to be able to see everything that you’d like to see. They’re moving around and quickly all the time. And so, it’s– I think I mostly look for parts that are going to stand out, like the black cap on a–, or bib, like bib on a chickadee. That’s obviously quick marker is that black and white face. And then you start to think about, oh the short tail and all that. Once you get to know the birds, then you recognize them.

So this is what I have to say is the difference between a beginner, they’re– experienced birders ID birds differently than inexperienced birders, because it’s all about recognition. That once you’ve seen birds, over and over and over enough. You don’t need to get all of the clues to pick them out. So the analogy I use sometimes is to see at a deck of cards that were all of the presidents of the United States, from George Washington to Joe Biden. And when we would hold one up, right? And you get one quick flash of who’s that president? And obviously, Lincoln would– everybody would get Lincoln like that, right? But then if we’re looking for Grover Cleveland and say, oh was he the one that had– does he have sideburns? We have a field guide to the presidency. The one had sideburns, but not the chin beard, and so then you have to figure it out when you’re beginning.

But that’s why sometimes a bird will just flit by, and I know what it is just because I saw general shape, and the way the bird was moving. And it takes a lot of experience to get there. Not skill necessarily, but just a lot of time– face time– with the birds basically. So look for whatever is distinctive, and eventually you’ll– once you get to know the birds, you’ll be able to identify a chickadee from behind, and you don’t see those big black patches and white cheeks.

[Lisa Kopp] Any tips for IDing males or females?

[Kevin McGowan] Well, in general, unless they’re really sexually dimorphic– meaning that sexes look very different– like a Cardinal where the male is bright red and the female is brown. Most of the time you can’t tell. Usually if the one– one bird is brighter than another one of the same species– There’s, again, there’s a bright and a dull. Usually it’s the male that’s brighter, but not always. There are a number of species of birds where it’s the reverse, where the female’s actually the brighter bird. And then some of them there are birds like– I don’t know how you do that. It’s like crows. Crows are– males are bigger than females. But that’s just the same as on average in the same thing is true in people. But we know there’s an awful lot of overlap. They have slightly different shape bills, but I don’t know how they tell each other apart. I have no idea.

[Lisa Kopp] It’s helpful to know that even you get stumped sometimes.

[Kevin McGowan] Well– if I get a good enough look at a crow, and then I can tell a lot of males from females, but I’m not laying money on that. Not doing that. There are some birds that have slightly different plumages that we can’t detect. That they’re in the– birds can see into the near-UV, ultraviolet light, the near-UV. And so, they’re seeing different colors than we are in some places, like in some of the European chickadee-type. The tits over there– they have the males and females don’t look that different to us, but they look very different to the bird. So sometimes there’s hidden dimorphism there too, because they have a different set of cells in their eyes.

[Lisa Kopp] Another one of those amazing facts about these animals.

[Kevin McGowan] Yeah, cuz they see UV. So, we see yellow and red together, it makes orange. But what’s yellow and red and ultraviolet? I don’t know.

[Lisa Kopp] Right, we don’t know.

[Kevin McGowan] Even– I can’t even– it’s like thinking in another dimension. Can’t do that.

[Lisa Kopp] Wow. I cannot believe it. We are at 12:55 already. Clearly, as we knew it would be the case, there are so many questions we haven’t been able to Answer. Kevin, is there anything that you want to talk about before I get into our wrap up announcements that you feel like we should have covered, or you really wanted to share with people?

[Kevin McGowan] Oh, I was– I just– we’ve covered a lot of points that I did want to share. The main point for me is just that keep asking questions and keep looking at birds. There’s so many fascinating things out there, and it’s– birds are– birds are so cool. It’s– I’ve been doing that my entire lifetime, and I’m not going to have time enough to get to know everything that I’d like to know, so. Yeah, that’s about the only thing I’ve got to say. Too many– everything the birds do is fascinating, again, from the inside out. Their physiology, their behavior. It’s just– it’s a pleasure to be able to learn about them. And one of the nice things about birds is they’re out in the daytime and you can see them. And that’s one of the reasons that they’re so popular. I mean I grew up liking mammals just as well. I got a master’s degree working on small mammals, but you had to trap them to have any actual contact with them. Birds are so much better.

[Lisa Kopp] Well, thank you for sharing so much of your knowledge, and for being able to roll with having all sorts of questions from all over the map asked of you. We’re so appreciative.

And I should say that for people who are interested in hearing more from you, you have an incredible catalog of courses on the Bird Academy website. I know I saw quite a few pre-submitted questions looking for tips on being able to differentiate sparrows and warblers. And you’ve got incredible things about bird behavior. And there’s just– for more from Kevin, specifically, but also just incredible resources. The Bird Academy course catalog is really an excellent place to start. And we’ll put that link in the chat.

So thank you all for your incredible questions and your patience as we try to answer as many of them as possible. Tomorrow, for those of you who signed up over Zoom, we will be sending a recording of this talk. And we will also list a couple of the most requested resources in that email. And then you can always visit or view this and our other recorded talks on the Bird Academy open lectures page. We can put a link to that in the chat as well. You could really while away days looking at the archives of past topics.

And if you’re watching on Facebook, check the comments for some of the links and resources that we’ve shared as well.

This webinar is part of a series. We spotlight programs and research from all around the Lab. And this work is funded primarily by people like you who choose to become a member. So if you enjoyed this webinar. I hope you’ll consider becoming a member too, by visiting

And, that’s all for today. Thank you again, Kevin. Thank you to our audience, and thank you to our wonderful team behind the scenes who have also been sharing links and trying to answer as many questions of yours as possible. I hope everybody has a great day and gets to go and see some birds outside sometime. All right. Thanks, all. Bye.

End of transcript
Kevin McGowan, Ph.D.
Professional Ornithologist, World Series of Birding Champion
Course instructor Kevin McGowan combines deep knowledge about birds with a passion for helping others learn. He is a professional ornithologist at...

Have you ever wondered why birds look different throughout the year, or how you can spot breeding behavior? Join us for an open Q&A session with renowned ornithologist Dr. Kevin McGowan. Learn the answers to your questions before the migration season begins! Submit questions in advance when you register or live during the webinar. We hope to see you there!

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