Spring Birding: Ask an Ornithologist

[Lisa Kopp] A few tech notes, closed captioning is available on Zoom. So if you’d like to turn captions on or off you just go to the bottom of your Zoom screen and choose to either show or hide subtitles. For those of you who are on Zoom, we are going to be using the Q&A question tool.

So if you’ve attended some of our webinars in the past, you may know that we often start out with a presentation or an introduction and we’ll hear from Kevin about his background, but really then we’re going to jump into this being a live Q&A. So the Q&A tool is going to be really valuable.

If you are watching from YouTube welcome, we’re happy to have you here today, you can use the chat function and YouTube. And we have a team of wonderful colleagues Mark, Leanne, and Sarah who are behind the scenes helping relay your questions, and answer your questions, and share what you are curious to learn about. So use the Q&A tool in Zoom to ask your questions and in YouTube use the chat function.

In Zoom, the chat is only going to be used in case something major happens from a tech standpoint and that way you can tell me your sound went out or your video isn’t working and we’re going to be sharing plenty of links there because there’s going to be lots of information we’re covering and we want you to be able to check out that information on your own afterwards. We always get this question, so I’ll just go out ahead and answer it. We are not able to send a list of– we cannot send the chat for privacy purposes. So if there’s a link that you’re really excited about, open it up and make sure you bookmark it or take a screenshot of the chat so that you can save that.

Last, we are recording this video, this webinar. So if there’s something that you miss or you want to make sure you’re following up on you’ll have a chance to watch it again. It will be posted on the Bird Academy Open Lectures page, which we’ll put a link to in the chat.

And we’ll be sending an email out with the recording to those of you who registered over Zoom. So we are excited today to talk with Kevin McGowan and let’s jump into things. So Kevin, welcome. Thank you for being here today.

[Kevin McGowan] Always good to be here. I like to talk words, I love to talk birds.

[Lisa Kopp] I know it’s so fun. And this time of year is pretty magical. So before we get into everyone’s questions, which we got so many great ones pre-submitted would you mind telling us a little bit about who you are, and what your background is, and how you landed getting asked to do this webinar?

[Kevin McGowan] Sure. I’m a professional ornithologist, that is I study birds, and I teach people about birds, and I’ve been lucky enough to do that for a long time now. I got my PhD working at the University of South Florida working with Florida Scrub-Jays looking at the development of social behavior in young jays.

When I moved here to Ithaca to actually be the curator in charge of the bird and mammal collections in the museum, I started studying crows. And I’ve been following a marked population of American and fish crows for 35 years now.

And I’ve tagged over 3,000 individual crows and follow them from nest to doom. We’ve had three birds that have lived to be 19 that I’ve followed that I knew as an egg and got to see them into their 19th year. So that’s been a lot of fun. A lot of my interest is there.

I also am interested in education, I helped start the All About Birds website and I am interested in everything birds there. I’m also a hobbyist birder, a pretty avid birder, so I’m interested in identifying them, and taking them apart, and seeing what’s inside, and knowing who they hang out with and why, and what they eat, and parts and phylogeny, so who’s related to whom, and all that stuff.

My interests are all over the board and so that’s why these things are so much fun that I get to talk to you on this. I should say that my main gig right now is creating courses in Bird Academy at the lab.

And if you don’t know about Bird Academy, look it up because we’ve got over 20 courses ranging from intro birding to university level ornithology course that we have offered for people to take online. And so that’s a fun job for me. And as I say, I’ve been getting paid to talk about birds for a long time and this is a lot of fun.

[Lisa Kopp] Great. And I will put the word Academy link in the chat right now because you are right, it is such an incredible resource, lots of free courses, paid courses, courses with you, courses on everything from nature journaling to sparrows, learning how to ID some of those very tricky birds.

So if you have specific questions related to things that we aren’t able to cover in this 52 minutes that we have left, that’s a great place for you to check out additional resources. So we wanted to make sure that we kick things off talking about migration. We’re into this, this is the time of year where we are, which is up in Ithaca, New York.

And so someone actually pre-submitted the perfect question to get this conversation going, which is, what is migration and why does it happen? They ask specifically is it food that creates the motivation to migrate, is it breeding, other reasons?

[Kevin McGowan] And that’s a great question. Birds move long distances or short distances depending on the species in the part of the world where they’re migrating. But some of them travel incredible distances from the Arctic and in Canada and Alaska down to Argentina and Chile or to New Zealand.

And typically, there are various reasons for it, but almost always the main thing is about food because birds are pretty hearty and there are a few species like snowy owl and willow ptarmigan that actually spend the winter up above the Arctic Circle and all the way in Northern Canada. And they can handle the cold and they can find food. Well, some of them can find food, not everybody can find food and that’s the thing, is that they can handle the cold.

Most little birds they’ve got a down sleeping bag around them the whole time in the winter, and so they can handle the cold but they have to be able to find food. And a lot of birds their main food is insects and I don’t see many insects in the winter.

If you like to eat insects, especially flying insects, well, then you better leave Canada and upstate New York in the winter because you’re not going to find anything. There are few birds that are resident that actually can find it, but they’re the birds that are actually pecking in the crevices and finding things like chickadees, and nuthatches, and some woodpeckers that are finding the overwintering larvae, and overwintering adults, and eggs and things like that.

But the fly catchers and the ones that catch them by seeing the insects move, they’ve got to get out of here and go somewhere else where there are insects or turn to some other food source. And it’s all about the food.

And it’s not just any old food there, we’ll talk a little bit more about this when we get into some other things, but they’re basically three things that birds need to do in a year. They need to breed, they need to change their feathers at least once, and they need to survive the rest of the year.

And sometimes the food you need to raise babies is different than what an adult can live on. Babies can’t drink beer, and eat olives, and stuff like that. Those things have toxins in them that an adult can handle, but a growing youngster cannot. And so its protein, it’s what the kids need to grow and prosper.

So birds move to places where there is heavy intensive protein sources to raise the young. But then after that they don’t need so much protein and they can do other things. And one of the things that some of the birds do is change their feathers.

And some birds actually migrate to a different place than where they breed to change all of their feathers because there’s different food sources that are available, different amounts of things that are available. And so you go where those are necessary and then move on to the wintering grounds where you can get by with whatever you need, no special needs at that point.

So those are the most of it. I mean, certainly some birds would die if they stayed up in the cold they’re not adapted to that, but those are secondary characteristics. Most of the problems that a bird tries to get away from have to do with food.

[Lisa Kopp] So I see one follow-up question Kathy have asked, “I’m interested in the opposite question about migration. Why do birds who live in Jamaica, where Kathy is, for eight months of the year go north instead of staying there?”

[Kevin McGowan] That’s an excellent question and it’s because the, again, food that there’s a huge resource of insects that come out in the boreal forest of Canada and up in the Arctic in North America. Same thing is true in Eurasia and Africa as well, is that there becomes a big opportunity for these birds to go exploit that.

And it’s not that Jamaica doesn’t have nice food, but, boy, again, if you like insects, try going to the tundra or the boreal forest in the summer and there are more insects than you can shake a stick at, in fact, I try to shake stick out.

[Lisa Kopp] Yeah.

[Kevin McGowan] So many of them around. So yes, excellent question. And we used to think of this, I was raised in the northern hemisphere and always felt like the birds were our birds that went down and wintered with you taking a winter vacation kind of thing.

But then I realized that no it could be there just like migrant workers that are going up to take advantage or they really live in Jamaica, but they’re just visiting us for a little bit of time because we’ve got resources that they can exploit. And as it turns out it’s both of those things.

And it looks like a lot of the birds that have radiated into the, I know that Neotropics is best, but some of the things like the fly catchers and tanagers that it looks that there’s so many different kinds in the tropics that we thought that, oh, that’s where they must have come from and we’ve just got a few of them that are expanding their range, I mean, we only have a couple of tanagers in North America.

But as it turns out looking at the history of the genealogy basically of these birds and who’s related to whom and all of that, who came off faster, it looks like a lot of the things were birds that were in fact in the north temperate zone and then discovered the Neotropics and then stayed there and radiated into a bunch of different species.

[Lisa Kopp] How come there are birds like chickadees or titmouse that stay in places like upstate New York all winter long? How are they surviving?

[Kevin McGowan] Well, it’s because they can do it. And that’s because they’re finding food that the other birds can’t exploit. And again, it goes back to how do you find your food? Everybody is aiming for similar foods, but how do you do that?

And there is a bunch of insect prey out there on the trees right now, well, over winter that the chickadees can poke into crevices and find that the warblers and the orioles just really couldn’t and so they go somewhere else. So birds do adapt to conditions in some amazingly harsh conditions and a lot of birds are resident in places where a lot of the year nobody else would want to be there.

[Lisa Kopp] So we’re getting a lot of questions about specific birds and is it safe to summarize by saying that specific adaptations and even preferences around food are what drive the differences between different species moving certain places?

I see a question about, why do ospreys move to South America, but bald eagles don’t even though they’re within a similar subset of birds? Is it safe to say that it’s really just adaptation and food preferences?

[Kevin McGowan] Well, yes. And I will say take a bald eagle and Osprey, they eat a lot of the same stuff, but they do a lot of different things. And one of the things that I’ll probably be bringing up several times today is that there are multiple correct answers for every evolutionary question. How do you do this? How do you solve this? How do you live in this place? How do you eat these foods? There are many, many ways to do it.

I think about this like you want you’re on the corner of a city block and you want to go diagonally to the other corner. Is it better to go right or to go left? And if all things being equal, they’re equally viable options. But in some places going right exposes you to tigers or something like that and going left is clear sailing.

And so then there are selective pressures, there are the ones who go right didn’t make it, the ones who went left did. And so they have that. But if the tigers disappear then that right direction is just fine again. And so there are just millions of ways to solve the simple question of, how do I find enough to eat and how can I breed?

[Lisa Kopp] OK, that makes a lot of sense. So how do we know when migration is going to take place? Does it vary year to year? Are there factors that go into when birds migrate? And how might we get– a little bit of a softball question because I have some advice for people on how to learn more on this, but I want to hear from you. How do we know when migration might be happening?

[Kevin McGowan] Well, migration does vary from year to year, depending on whether variables or other things out in the environment that might be different from year to year. So there’s a little bit of variation about when things might be happening.

But in general, migratory birds are fairly consistent in when they make their movements, sometimes amazingly consistent down to the day for every April 5th for five years in a row somebody gets a phoebe coming back to their place, that stuff happens. So there are general patterns to watch for.

And the lab does have a couple of fun tools that help with that. One of the ones is if you want to know when certain birds come through where you live, anywhere in the world basically, eBird has a tool for that. And you can find a location and find bar charts to that.

Again, you plug-in your location and it will give you a list of all the birds that have been recorded in eBird at your locality and it will show you a diagram where that very thin line means none. If there’s blank, there’s none. If they’re very thin it’s just a few. But if they’re big bars then they’re a lot.

And you can scan through those bar charts and look to see, I know this bird doesn’t stay here and breed, when does it come through? And for here in New York for something like an olive sided flycatcher that breeds up in the boreal forest, they come through here in late May and the 1st of June, then they’re gone, and then they come back in late September, early October and then they’re gone.

And so that’s a visual aid for you right there to be able to say, OK, I’m waiting for– it’s the 1st of May there’s a bunch of stuff that ought to be coming in. As far as year to year variation goes, we have another great tool that, I think, has been already introduced in the chat is BirdCast.

A project based at the lab that looks at migration happening now and can tell you tonight’s going to be a great night, there are going to be a bunch of birds moving where you can get up in the morning and say, did anything new come in?

And it’ll be like, well, we estimated that there were a million birds that flew over your county last night. And so there ought to be a couple of them hanging around. And those are just fun tools from the lab that allow you to do that. And as I said, because eBird is worldwide, you can find it for Jamaica and Sri Lanka as well, so there is some information.

Might not be as much information as there is for the US and Canada, but we’re working on it. And so those are ways to think about things and to get a quick start on, when does something come by my house?

[Lisa Kopp] Yeah, great. I did put links to both the eBird bar chart, and the BirdCast websites in the chat, and then a link to that upcoming BirdCast webinar, which is on May 1st where if you sign up for that webinar you’ll see all sorts of information about how you can use that tool to understand what’s happening most of the time at night.

So then the follow-up question, Kevin, for you is, when are birds migrating in terms of a 24-hour daily cycle? Is there a time of day where they’re most active?

[Kevin McGowan] Absolutely. For the long distance migrants especially most of them migrate at night. And it’s hard to see, you can’t see them very well as you go unless you go like this and find the moon and watch them fly by, which is actually a thing that before we had radar and all these other casts people would go out and do this.

They would put a telescope up and count how many birds would cross the surface of the moon in an hour and that was where they got their data. They called it a ceilometer, watching the moon and watching birds fly by the moon. It’s really cool actually to see birds fly by the moon at night.

But there are a lot of birds moving at night because for various reasons, but one of them perhaps is it’s safer and because they can’t forage at night they can fly higher they don’t have to worry about where they are till they come down.

Now, there are other birds that don’t do that actually migrate pretty much only during the day, some things like the hawks and vultures that they use a lot of sun generated energy, these thermals that the sun heats up the ground and the air gets hot and it rises.

And then the vultures, they can see the hawk making lazy circles in the sky, what it’s doing is using that upwelling of air to keep aloft and so these hawks can travel thousands of miles with very few wing beats because they’re basically finding a thermal and going up and then riding down until they find another thermal that takes them up again, and it’s all with very few wing beats.

And then there are other things like the hummingbirds that in North America that migrate. They need a lot of energy to migrate. And so they do a lot of foraging as they go, so they’re feeding as they go along. Other things are, they fly a long way, stop, and sit at a stopover, and feed for a couple of days, then fly again for a long distance.

And some hummingbirds can do that, but they more typically are moving just a dozens of miles a day as they feed as they go along. So there are a number of birds that are like that. American crows are like that too. The ones that do migrate tend to migrate during the day, and stop, and feed as they go along. But again, different strategies that they all work.

[Lisa Kopp] Yeah. So if birds are migrating at night, how are they seeing where they’re going? How do they know where they’re headed? There are some wild and fascinating theories around how birds know how to get generally where they want to go, but as you were saying sometimes very specific in the way that they might leave on the same day, year over year some birds are going to the exact same location. How are they doing that?

[Kevin McGowan] Yeah. Well, it’s a fascinating thing and as you know, it’s complex. But there are ways that the birds can– they have basically a pattern in their mind that’s genetic that it’s encoded in what we call instinct. But what they do is that it’s like I know when I get so much hormones flowing because of the change in daylight length then I need to start doing something and I’m going that way.

And then how they deal with it is we’ll get into in a second. But I just want to make this so that you can feel it’s not like they have little maps and know exactly where they’re going, they have the need to go somewhere at a particular time, but where they are going and how it works out is variable with the environment.

So for example, humans as animals, we have an instinct, we’re genetically predisposed as babies to look at other people’s faces and to try to learn a language. I mean, we can’t help doing that, that’s as encoded in our genes as anything about migration and birds. But what language we learn, that depends on where we’re raised.

And so how it all plays out in the end is a mixture of nature and nurture and the birds are the same way. A lot of them do learn their roots, they learned the routes that they go, very few follow their parents. But a lot of them have amazing abilities to go to someplace they’ve never been before.

And a lot of it, again, how they do it, they can they have different senses they do watch the sun, and the stars, the movement of the stars. We know that the birds at night navigate by the pole star and following the way the stars move.

They also have some ability to see the earth’s magnetic fields, which is a visual thing that we talked about last year about this where they actually are these pigments in the eyes that in a certain light level they get an electron that gets bumped up into a different shell that puts them into a quantum state where they can actually see lines of force of magnetism and that’s amazing.

And so they have the ability to do some of this. They also can hear infrasound, so they can hear things like the ocean waves potentially and stuff like that. And then they put it all into a little package and make it work. And it’s just incredible, just incredible.

[Lisa Kopp] It really is. And I know that there’s lots of analogies about how birds do the things that they do. I had not heard the language one, but that’s so helpful. I feel like that’s a really clear way to understand that there are just some things that happen, but that the combination of nature versus nurture is then where there are the differences between them.

[Kevin McGowan] So that’s the thing that I’ve always had on that particular argument. It’s not nature versus nurture, it’s nature and nurture.

[Lisa Kopp] And nurture. You’re right, yeah.

[Kevin McGowan] You can’t get away, there’s not an organism. Well, there probably are some organisms that don’t learn anything and are completely successful surviving. But yeah, you can see it could be very difficult to rely on only one of those things.

[Lisa Kopp] Yeah. Wow. So birds are doing a lot. They’re figuring out where to go, and when to go, and how to go. Are there things that we can do to help birds while they’re migrating? We got a lot of pre-submitted questions about, are there ways that I can support them? Or do they need food? Or what can I do to help these tiny creatures on these long journeys sometimes?

[Kevin McGowan] Yeah. Well, one of the things you could do is turn out your lights. And we know this can be a big problem, especially in big cities. These birds learned to fly at night migrate at night before there were electric lights. And so it’s pretty easy to know which way is up when the sky is always lighter than the ground.

And so that’s what a lot of these is the same thing that why moths come into a flame, is that there’s a thing in their brain that says, fly to the light, fly to the light. And when birds get into big cities with all this light they get confused. They literally don’t know which way is up and they keep having this thing attract them that they find it hard to break away from. So the lab is part of a program with– don’t you help me with the name of it?

[Lisa Kopp] Lights Out?

[Kevin McGowan] The Lights Out program to try to get cities, especially big cities in major migration routes like Houston and Chicago that are right on the flight lines of millions of birds moving over in migration to try to get– especially when it’s going to be a big migration night, which we can now predict to some degree that if they can get a program to get the people to turn out their lights, that’s a good thing, it can save the lives of millions of birds that would otherwise whack in the windows because they’re so confused. They don’t know what they’re doing.

Other things are if you’re going to support migration going through plant native plants that will feed the birds as they come through. Hummingbird gardens to help the hummingbirds come through both going north and going south. Keep your cats indoors, that’s always an easy one to tell people. And yeah, providing feeders that certainly the Baltimore Orioles when they come back or are passing through love it that people put sliced oranges out there for them to eat and stuff.

And bird feeders, not a lot of birds will come to, although really migratory birds will come to bird feeders, but they will. It’s like right now the white-throated sparrows are coming through here in Ithaca, New York and the feeder outside my window has got a dozen of them underneath it. So you can provide food, water, resources for birds. And it’s not going to help everything, but it’ll help.

[Lisa Kopp] Yeah. Great. So what about outside factors like weather? What are the things that can get in the way of birds trying to migrate or might help them on their journey globally?

[Kevin McGowan] Yeah. So birds want to save as much energy as they can. They’re going to make some amazing flights and use. I mean, some birds double their body weight in fat and then burn all that fat up while they’re flying in migration and then needed to get more fat. Pardon me.

So anything that can help birds take advantage of. Just as I said, the raptors using the updrafts to gain height so they can fly farther with less effort. The weather fronts are a big deal because birds when they get aloft they’re not just flying, they’re also surfing. And you can think of it that way is that if they have a tailwind that’s so much better than having a headwind.

Some birds will fly against a headwind, but boy, they would so much rather have it behind them. And when these fronts come through you can watch the big fronts that have– suddenly bringing up all this– a cold front coming across Canada and the Eastern US that brings up all that warm air going up north through the center of the continent, that’s– yeah.

Again, they surf that stuff that it’s just an elevator to Canada to get those things going through and that’s why there are so many migrant birds that go through the middle of the continent. It’s easier to see concentrations of migrating birds on the coast because they run out of land and you can find them pushed up against it.

But in the Midwest and the Great Plains, these birds that are going from Central and South America to the boreal forests, they’ve got a great shoot going up that way. And, yes, the birds pay big time attention to what the weather is like aloft and take advantage.

And then just like when the wave ends if suddenly the stars come in from the North, if they’re trying to get into it again then they’ll drop down and feed for a while before they need to move on.

[Lisa Kopp] So it sounds like there’s some natural element to birds migrating in flocks or large groups, but I also see even just in this area huge flocks of red-winged blackbirds, or starlings, or someone wrote in about bushtits, why do some birds seem to stick together in these groups? And then what motivates them to eventually leave the group or set up their own territory? How do those things happen?

[Kevin McGowan] Yeah. Well, there are three basic reasons why we see large social groups of animals, larger groups of animals. One is often about food, that they’re all going and exploiting the same food resource because they can get together like that. The other is about predation that there is safety in numbers. And a big flock of birds isn’t going to attack a predator at least there are more eyes to watch for it.

And if I’m in a group of 1,000 individuals, and a bald eagle comes along, and it’s going to take one of us, I have one chance in 1,000 of being the one that gets taken. So lots of reasons to cluster in groups. And we see this all the time both within species where you’ll see things like Canada geese, snow geese.

We see traveling flocks of hundreds of thousands of snow geese coming through Ithaca in the spring, but you also see mixed flocks of birds like we do see a lot of mixed waterfowl, but also flocks that hang together in the day that you can see foraging through the woods.

And I think in India they call them hunting parties, here we call them mixed species foraging flocks where you have a flycatcher, and a woodpecker, and a chickadee and a nuthatch hanging together and moving through the forest together because they get something out of it.

And again, a lot of protection. And think about it, if you fly catchers flying insects, woodpeckers are pecking into wood for things, the chickadees are moving around and looking for moving stuff, and then the nuthatches are upside down poking in the bark as well.

So it doesn’t hurt them, they’re not competing, they’re complementing each other. And they, again, the may eyes deal works often. In some places there’s a bird, usually the one that’s the aerial predator or waiting for flying insects, So. It’s sitting around watching and they’re the ones that see the predator and make an alarm. And so there are advantages to that.

But there are also times when you want to be alone and you need to concentrate on what you need to do, which is raise a family. They get to certain times of the year where things like bushtits, which get together in fairly large pretty cohesive of groups during the year, but then they need to go and stop moving around a little bit and sit down on a nest of eggs.

And blue jays do the same thing that they travel around in a group of a dozen birds through the winter and then they want to come now when they’re starting to breed. It’s like no, no, I’m not going to hang out with you guys today. It’s like we’re going to concentrate on this over here.

And so a lot of birds have that difference. They have things that they need to do and sometimes they need to be real territorial about it. And I think the red-winged blackbirds are funny because we get them here at the lab that breed around the pond and they’ll come in this monstrous group of 100 birds or so, actually sometimes more than that, and if it’s a nice day then they spread out around the pond and they act all territorial.

And they’re like, yeah, you try to come over onto my territory? Buddy, I’ll beat your red wings up. And then it gets cold and they’re like, oh, let’s all go to the feeders. And then they sit beside each other and they cover up their red, so they aren’t flashy, making anybody hungry.

But it’s just like I remember an old Road Runner cartoon about the sheepdog and the Wile E. Coyote that came in and punched in the, hey, Fred, how are you doing today? Hi, Bob. And they both clock in and then they go to their separate jobs where they’re trying to be an antagonist. But then it’s like, OK, we’ll check it out. Let’s go get a beer or something, that’s exactly what the red wings look like.

They need to do different things at different times and a lot of the external things work on the internal things. So with the change of daylight length and seeing nesting places, those actually change the hormones that are moving through a bird’s body and make their reproductive organs grow in the spring and that sends a whole bunch more chemicals going through that suddenly make the birds do different behavior.

And so that’s it, is the situation comes together at some point where all of the hormones are right, that it’s time to stop being in a group and try to raise them young.

[Lisa Kopp] OK, So that’s a perfect segue into the nesting conversation and how it’s related to migration. So you answered the fact that migration and nesting are often tied closely together, is that fair to say for most birds?

[Kevin McGowan] In some way, yeah. I’m trying to think how of exactly where– most, but not all migration is to go to places where you can breed or to move away from a place where you can breed in, but you can’t survive there. But birds, they also do this molt migration as well where they’re moving to a place.

Again, this is usually after the breeding is done and they go to two different places in the non-breeding season. One of them, so they can molt there and then the other just because they can survive and do what they need to do. So breeding is always in the mix, just isn’t always the only reason that you go to a particular place. There can be multiple reasons to go to multiple places.

[Lisa Kopp] There’s an interesting question here that actually I’m curious to ask related to both migration and breeding, which is success. So Maria has asked, “What percentage of migrating birds survive their treks?” And then I’m also curious to know what percentage? What’s nest success? What’s the average rate? I know it varies across species, but is there a general percentage of success?

[Kevin McGowan] Yeah, there is and it’s scary.

[Lisa Kopp] Yeah.

[Kevin McGowan] So the numbers I know are based on north temperate birds like an American Robin, something like that, the nest in an open-cup, an open-cup nester of a past serene about the size of your fist something like that.

Of all of the nests that are started eggs laid in them go to young, about 75% of them get eaten. So only 25% to 30% of nests in a temperate zone, this is true in Europe as well, produce any young.

And of those young that they produce, and this, again, is for a short distance migrant, about 8% are still left alive the next year. So again, you lay hundreds eggs or make 100 nests, you get 25 that produce young. So you have 100 young that are produced and then there eight that are coming back the next year.

[Lisa Kopp] And then when you add in human factors, those numbers are going to continue to decrease likely.

[Kevin McGowan] Oh, yeah. But I mean, birds have been dealing with these numbers forever and that’s why mourning doves can breed 12 times in the summer, they’ve been dealing with that.

But there is a lot of successes slow along the way and some of that will be– there is this thing called compensatory survival or compensatory mortality, which means that of the 100 robins that headed off, if one of them hits your window, that robin is not like, oh my God, that that’s definitely going to affect the number eight because that robin might have been one that would have died right away.

And so there’s just– this is the thing that allows duck hunting to go on and not affect the populations because they know that they’re going to be a certain number of these young birds, especially that die anyway. And so you can essentially can take a limited number of that up, and you get up to a point, and then you start affecting it.

But you can actually hunt ducks to a certain level that doesn’t have any effect on their population size or growth. So it’s just a mean world out there. And young creatures find amazingly creative ways to die.

[Lisa Kopp] Yeah. So you mentioned cup nests. Nicole submitted a question in advance asking, how and why there’s such an incredible diversity in nest types. Are some safer than others? Do we have any theories around why there’s such a huge diversity among nests?

[Kevin McGowan] Well, again, I’ll say because there are many, many answers to one single question in the right. So is it better to be in a cup nest in than a platform nest? For some birds it’s fine, other birds maybe they couldn’t pull it off.

We do know that wholeness tend to be safer than open-cup nests. But the problem is there aren’t that many holes out there because I mean, if I’m a cardinalogist I’ll just make a cup nest, right?

[Lisa Kopp] Yeah.

[Kevin McGowan] But if I’m a woodpecker, I’ll just make a whole nest. But if I’m a chickadee that likes to nest in holes, I can’t go bang my head against the branch and make a hole that big as big as I’d like to go in. They’ve got to find one somewhere.

And that’s why there’s a huge amount of competition for cavity nesting birds. You’ll see bluebirds and tree swallows fighting with each other because they both want to use that limited resource.

That’s why starlings were a big deal when they were introduced into the North America because they’re a cavity nester, and they’re aggressive, they’re tough as nails, they’re really strong for their– I mean, I’ve skinned a couple and they’re like wow, you weigh like half again more than you should for a bird your size and it’s muscle. Halle sparrows the same way, also competitors for nest sites.

So we know that holes are good, but the holes are limited and that’s why nest boxes work so well. That’s why we have had this whole nest box network for a while and now it’s in the project nest watch that does a lot with nest boxes because they really work because you’re providing a limited resource for a number of species that would– and a safe resource.

Yeah, different nests work for different organisms. For one thing the ones that make the big nests and pretty much the only birds that reuse nests are ones that are too big to worry much about predation. So we see things like the eagles and ospreys and we used to have the heron cam here with these big open nests.

And the deal is that they’re not that much in danger of being eaten, whereas if you’re a cardinal or a song sparrow or a bushtit, that there is a risk of that and you need to hide your nests. And typically birds don’t reuse their nests because it’s already a known location, so they want to mix it up.

And again, you can only reuse your nest if you’re big enough not to get eaten easily. And even American crows weigh 500 grams that’s it’s 2 pounds and they’re pretty good sized birds, but they never reuse a nest except in odd locations like in Urban Seattle where there’s not enough nest sites.

But around here in Ithaca, I’ve never had a crow reuse nest because they’re still risk, they still get deprecated, and so it’s a risk to go back to a place that everybody knows where you’re nesting.

[Lisa Kopp] Yeah. Wow. So if there’s a nest left over from another bird, if a crow abandons a nest would a– I don’t know. They’re pretty big, that’s hard to make a swap. But you know what another bird that’s like, oh, look at this empty nest absolutely. Maybe I’ll do this.

[Kevin McGowan] Absolutely. There are two types of common birds that about that are fairly large birds that do not construct their own nests, they do not make nests and that’s owls and falcons. And so yes, great horned owls will use old American crow nests.

And merlins, the small medium-sized, small falcon that is expanding greatly in the US and Canada over the last decade, they love old crow nests. And here in Ithaca we’ve got fish crows, which are a smaller version of– it’s a Southeastern US endemic that is about half the size of an American crow, and they make really, really good nests.

And they’re expanding up from the south. Now, merlins are actually expanding down from the north. And so we’ve got here in Ithaca pretty much the first time that merlins and fish crows have ever interacted before. And the merlins love fish crow nests.

And they started off using the old ones, the ones from last year, but now they’ve started actually attacking some of the fish crows and some American crows to trying to get them off the nest to abandon it so they can nest in it. And in fact, a sad story. The oldest crow that we’ve ever known, I knew her as an egg and she was a breeder at four and bred for 15 years that we followed her.

So she was 19, and she was sitting on eggs, and a pair of merlins came in and actually harassed her off the nest and took over the nest. And she started to build a new one, but then she disappeared so we never saw her again. I like merlins less than I did before–

[Lisa Kopp] Yeah. Right. So because you’re a crow person I want– someone asked a question about, crows make shrieking at really large mammals like deer. Are they actually worried about that predator or is that just something else going on?

[Kevin McGowan] I’m not sure. Crows do have a lot to say about predators to the predators, to a predator, do a lot of mobbing as we call it. But deer I’m not sure what they would have any interest in deer. They do pay attention to foxes and cats, especially when they’re younger out and are recently fledged, and they worry about a lot of things that they normally don’t pay any attention to.

But I’ve a couple of times been with a companion and heard something out the window and I said, oh the crows are mobbing a fox and we go to the window and there’s a fox running by because it’s not the same thing as they say to a great horned owl, it’s a little more subdued in a different tone, but I’m not sure.

Sometimes crows will also mob places where there’s certainly a dead crow they would mob heavily, but also other large dead birds that they’ll– and so I don’t know if the deer had anything to do with something like that or it’s hard to say exactly because I’m not sure why a crow would be mad at a deer.

[Lisa Kopp] Yeah. I thought it was a fun question I wanted to ask. We have so many questions here. I mean, they’re excellent. I’m so sorry we won’t be able to answer all of them, we only have about seven minutes left.

So Kevin, what do you have any thoughts on– should we cover feathers? Should we talk a little bit about birdsong? Any preferences on– I mean, we could really talk about anything because there are so many excellent questions that really do–

[Kevin McGowan] Well, why don’t we talk about feathers a little bit because there are some interesting patterns in there that most people might not know. Feathers are like our hair and our fingernails, they’re dead substance, but they don’t keep growing. But they’re made of the same material, keratin and they wear out.

Feathers are important for birds for a number of reasons. One is that it helps them fly, it makes them sleek and aerodynamic. The feathers in their wings actually move the air to make such stuff happen and they eventually wear out.

So the birds do have to replace them at least once a year, some birds do it two times a year, other ones like goldfinches have weird, they’re replacing bunches of body feathers all the time, it’s that weird. And so I already mentioned that when they need to molt, they can– some birds go places where the food is really good for them to molt, but not everybody does that.

And somebody I saw in one of the questions asked, is this a big deal? Is this another stress on a bird’s life? And yes, it is, that molting is a very significant portion of a birds life and as I said, it’s one of the three things that needs to be done. You have to change your feathers at some point.

So there are a couple of things that go in with this. One is that it takes resources to do it and the other is that you can make good things out of it. So it’s like, oh, I can change from a dull and camouflage thing into big and showy bird for breeding season. And then you can say, whoops, breeding season’s over, I want to make myself as less conspicuous and then molt into something else.

So you can change your appearance, but it does take resources and it takes time. And when you think about it, a bird’s wing if it has a hole in it, it’s not as effective at moving air. And so how do you do that? How do you change all of the feathers in your wing without seriously affecting your flying capabilities?

Most birds do it by changing only one at a time, so there’ll be one secondary on the back part of the wing and one primary up in the hand part, so they’ll only be a small gap. But that means that it takes time and resources, so you’re going to have to spread it out all over the place but most birds do that.

But sometimes if they’re things with really long wings like vultures or some of the seabirds like albatrosses, they’ve got such a long wing they have so many feathers to replace that they can’t do it all in one molting season. And so they have to do what we call suspend molt.

And you can see on an albatross’s wing, you can see a record through the mostly secondaries, of which they’re I don’t know how many couple of dozen, you can see waves of different colors in the wings. You can see this in a turkey vultures wings pretty easily too, some will be dark and some will be lighter.

And those are older feathers, the lighter ones are older feathers from a previous molt cycle that didn’t get done. And so then when they come back in molting again, they’ll start their molt through those. So it’s a real interesting way to do that.

Now, if some birds don’t mind not being able to fly for a given period of time and these would be the water birds, the birds like ducks, and geese, grebes, and loons that can swim for a month when they do that. And so that’s what ducks do is as soon as the males help the female, the dabbling ducks mostly, find a nest site protector while she’s doing it and then when the chicks hatch the males leave.

And so they go to places where sometimes gather up together and they molt all of their flight feathers all at once. And they also molt all of their body feathers, the showy body feathers into a really dull plumage. And then that’s how they take care of that is, OK, well, I can survive swimming around for a month, I don’t have to be able to fly, and then they can do it all at once. So it’s a different strategy than a lot of other birds are able to partake on.

[Lisa Kopp] It’s incredible. And I can’t actually believe that we’re already at 12:58. So I want to get to some of the wrap up information. There is so much more to learn. Kevin has so much more to share.

And one way to learn some of that is through a link I just put in the chat, which is the Joy of Birdwatching course that Kevin leads on Bird Academy. It’s an online self-paced course with so much information on these and more topics. And so that’s a great way to continue expanding your knowledge.

I also put a link to the sign up for additional webinars. So we have quite a few scheduled over the next couple of months that would talk about things like these and other resources and information to help you learn about birds and biodiversity. For those of you who signed up over Zoom, we’ll be sending a link out to the recording.

I know we covered so much information and so being able to watch it again, pause it, check out a link, go back and do a little research, start Kevin up again. It’s really nice to be able to dig into some of the topics more. And I want to do a huge thank you to Mark, Leanne, and Sarah who are behind the scenes helping answer questions.

There would have been many more unanswered questions had they not been available to help you, to help relay what you were sharing and provide some context for things. So Kevin, thank you so much for taking the time. I mean, you’re so knowledgeable.

I’ve worked with you for years now, but I learned something brand new and I always walk away from these conversations feeling extra excited about birds even though I’m totally in that frame of mind most of the time anyways. So thank you for your incredible knowledge, and your enthusiasm, and for sharing that with so many of us today.

[Kevin McGowan] Yeah. Well, thanks for giving me an opportunity to share it. Clearly I enjoy it and I think it’s worthwhile and fun because people love birds, birds are cool.

[Lisa Kopp] They are amazing. And I hope everybody can enjoy seeing some birds today. Thanks, everyone, and we’ll see you soon.

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