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[Chelsea Benson] So we’re going to get started. I want to welcome you all to today’s webinar from the Cornell Lab of Ornithology. We’re going to be discussing how to identify common backyard bird nests and eggs. And we’re also going to be learning about birdhouses and how to participate in NestWatch, which is a citizen-science project.

So my name is Chelsea Benson. I’m on the Visitor Center Team at the Cornell Lab. And I’m going to be facilitating today’s conversation. And with me are the two experts from the NestWatch program. First up, I want to introduce, Robyn, who’s our project leader with NestWatch. So, hey, Robyn. Thanks for joining us.

[Robyn Bailey] Hey, Chelsea. Thanks for hosting.

[Chelsea Benson] And also with us is Holly Grant. And she is the project assistant with NestWatch. So thanks so much, Holly.

[Holly Grant] You’re welcome. Good morning. Excited to start this today.

[Chelsea Benson] Me too. So before we jump in to our conversation, there’s some announcements. So bear with me. There’s quite a few announcements. Closed captioning is available. You’re probably seeing a transcript go across the bottom of the screen. I’m going to be asking Robyn and Holly a few questions to kick off our conversation.

But there’s other ways that we’re going to be interacting with our audience today. And one of those is with the Q&A feature in Zoom. So if you look at the bottom of your screen, there’s a Q&A window. And you can add your questions there. If you like somebody’s question, and you’d like for us to answer it, please click the thumbs up icon. And that will make sure that it comes to the top of the list and gets our attention.

We’ll also be typing in some answers. I have a colleague behind the scene who’s going to be answering your questions. And look for those typed answers in the answered column within that. You can also use the chat. And I see a lot of people are using the Zoom chat right now, which is awesome.

We’re not going to be monitoring it for questions. It’s more for tech help or to chat back and forth with each other. And if you want to change it from to panelists to panelists and attendees, that way everybody can see what you’re chatting.

And we’re also streaming to Facebook right now. So if you’re watching on the Cornell Lab of Ornithology or the NestWatch Facebook pages, you can add your questions to the comments. And one of my coworkers is monitoring those and will be sharing those questions with us.

I just want everybody on our Facebook audience to be aware. There’s a lot of spambots on the pages right now. Please don’t click any links that aren’t from the Cornell Lab of Ornithology or from NestWatch. So don’t be drawn into their trap. Don’t click the links unless they’re from us.

All right. That was a lot of announcements.


So let’s get started. Robyn and Holly, I’d love if you could introduce yourselves and give us a little bit about your background and your role with the program. So let’s start with Robyn and then Holly.

[Robyn Bailey] Great. Thanks, Chelsea. Hi, everyone. I am Robyn Bailey. And as Chelsea mentioned, I am the project leader for NestWatch. And I’ve been with the NestWatch team for about 10 years now. So really enjoy working with this wonderful project and the wonderful citizen scientists that support it.

A little bit about my background. I come from a wildlife biology background and have studied various things from bird’s nest to rattlesnakes. So I really enjoy thinking about ecosystems and how we can work to best support them. So that’s me.

[Chelsea Benson] Awesome. Holly.

[Holly Grant] And I’m Holly. I am the project assistant for NestWatch. So actually, Chelsea was the assistant a few years ago, and I took over for her. So I’ve been at the Lab for about five years working at a few different areas. Right now, I am project assistant for NestWatch and for Project FeederWatch, which is wrapping up its season in another month here.

So you could email us or call us. I’m usually the one that will answer. And I’ve got a whole bunch of experience answering all those questions that you guys have. So I’m excited to start that today.

And in terms of my history, I have a biology degree with SUNY-ESF. And I’ve done a lot of fieldwork with birds and all that kind of thing after I graduated. So plenty of experience there.

[Chelsea Benson] Awesome. Thank you so much for sharing. So, Robyn, could you tell us a bit more about the history of NestWatch? From my understanding, it’s one of the Lab’s longest-running citizen-science programs. And over its lifespan, how has it evolved and changed?

[Robyn Bailey] Yeah, that’s a really good question. And I think someone did do the math and figure out that it is the longest continuously running citizen-science project here at the Lab. And it got its start back in the mid-1960s– in about 1965– when a program went national called the North American Nest Record Card Program, which is a real mouthful and very difficult to say. So over time, it changed names a few times. And the scope of the project has changed as well.

As I mentioned, it was the North American Nest Record Card Project. So people would mail in these physical index cards with bird nest information on it. And we have cabinets full of decades of that data. And somewhere in the 1990s, the project modernized and became– it was the Bird House Network, and then eventually became NestWatch as the scope changed from just birdhouse nesting birds to any nesting bird.

And with that change, we’ve been able to welcome a wider variety of participants from various places around North America, and eventually, around the world. So international audience is growing as well as the project opens up and changes scope over the years. So it’s not solely a US project. In case you’re curious, we can have participants report any bird nest from anywhere in the world.

[Chelsea Benson] That’s really great to know. I know our audience– we do have a lot of representatives from the US and Canada, but we do have people from all over the world. So it’s really helpful to know that this project can support them as they go out and find bird nest as well.

So, Holly, could you talk a little bit more about how people could get involved? And if there’s any special training? I know we’re working with baby birds, and nests, and eggs, and that’s a really sensitive time in a bird’s life? So could you talk a little bit more about that?

[Holly Grant] Yeah, sure. So anybody who’s interested in submitting data to NestWatch is more than welcome to do so. It’s a free project. All you have to do is create an account on our website. And then we ask you to go through our code of conduct, which is just a short list of guidelines, that we ask you to follow while you’re monitoring these nests.

So those guidelines help prevent too much disturbance to the nest. So we use our research methods for checking these nests. So that you can gather enough data for us to make sense of it and use it in our analyses. But also, not checking so often that you’re going to cause the bird to abandon its nest or something like that. The safety of the birds is of the utmost importance.

So going through that, it’s a super easy little quiz there. We say quiz, but it’s really read through the instructions. And we just ask a few questions to make sure you’ve taken in that information. And then you can just get started entering data.

So we do recognize that monitoring birds can be– like you said– sensitive, right? Even if we do everything right for them, there are still chances of things going wrong. So just as a forewarning to everyone. It’s not all sunshine and daisies. But it can be very rewarding. And it’s really great to watch those birds fledge.

[Chelsea Benson] Yeah. So it can be any nest anywhere. And then can it be like, OK, I saw those eggs in it? I start monitoring it now. Like how does that work? Can you just check in on the nest periodically? Or what happens if you only see it once or twice? Is that meaningful to NestWatch?

[Holly Grant] Yes, absolutely. So even partial data is useful to our database. So let’s say, you find a nest and the chicks have already hatched. You can still report on that nest until whatever outcome the nest has. And that data is useful to us.

So start at any point in time. If you can only visit it once a week, that’s OK too. We do ask about one to two times a week is ideal. But if you’ve got some things you have to work around your schedule, it’s all right to move that around a little bit.

[Chelsea Benson] Yeah, cool. So, Robyn, it seems kind of funny. We’re talking about NestWatch right now. Because like Holly said, here in the northeast, there’s snow on the ground. It’s 20 degrees. But NestWatch isn’t just where we are here. Could you talk about how the nesting season is starting in some places around the country? What birds might people be seeing nesting already?

[Robyn Bailey] Yeah, that’s a really great seasonal question. Because we are actually already seeing– as we do in every year– birds starting to nest in February. From our friends down in Florida, in Texas, Virginia, out West, California, New Mexico, birds are starting to nest for their regular nesting season.

There are some birds that will nest very early, like owls, can start nesting in January and February. Even here in Ithaca. So depending on the species, it could be normal for them to start in the winter. But as it’s now approaching spring. And we are starting to see some onset of nesting in the southern states, I would say that nesting season is definitely here.

We have had already some participants sending footage of bluebirds making nest in Florida and Virginia. So they’re definitely checking out those boxes. Other birds are starting– if they’ve not started nesting yet, they may already be starting to establish their territory, singing to attract a mate, engaging in some courtship behaviors.

So there are some things that birds will do to get ready for the actual building of the nest. So if you’re not seeing nest building yet, just keep your eyes open. You might see mourning doves flirting with each other. You might see some singing behavior as the daylight increases. So it’s definitely coming. And I’m seeing some signs of spring here even with snow and ice on the ground.

[Chelsea Benson] Yeah. People have been emailing me in the buildup to this webinar. And one of the things they’ve been saying is like, I’m seeing birds sitting on the nest boxes. It must be getting close. And so as you’re saying, you’re seeing those early nesting behaviors, which is really, really cool. When is the typical peak nesting season across North America?

[Robyn Bailey] North America is a big place. The peak–


[Chelsea Benson] It’s really a narrow window, sorry.


[Robyn Bailey] The peak kind of starts in the southern latitude, and then it rolls up. So we’re starting to see the early nesting, as I mentioned, in February. So peak for our friends down south, it’s going to be– March, April, May. As you move north, for example, up here in the northern states– April, May, June, July is peak nesting season.

And then our tail end will start to taper off in August. Whereas most of the nesting down south is finished before August. But up in Canada, it can start a little bit later as well. And also go a little bit longer because the birds didn’t start as early.

So it really depends on where in the country you are. But we’re right up on the crest of peak nesting season. So this is just about the time to get those nest boxes up. Or if you’re going to make some improvements, this will be a great time to do that.

[Chelsea Benson] Awesome. I know that last year was a really different year for all of us. And one thing that was a phenomenon that happened is a lot of people were spending more time in their backyards, exploring their local parks, just staying local but becoming really attuned to things that were happening. Did you see any changes in data from NestWatch during the last year? Or last nesting season?

[Robyn Bailey] We certainly did. As was common with some other projects at the Lab, we saw a boost in the number of people that were participating. And the last that I looked at it, we had about nearly a 40% increase in the number of people that were reporting to NestWatch, which is great. And an equivalent boost in the number of nets that were submitted.

So we did see a lot of participation in terms of people reporting this. But also– and maybe Holly can speak to this– an uptick in emails, and questions, and people finding things, and asking questions about it too. So we really saw the increase in people noticing.

And I know personally. I worked from home and spent the summer, looking out my window at home, and definitely saw more birds than I did. Well, not more birds. But I saw more birds nesting around my home. That I might not have noticed the year before.

So I was seeing many more species checking out my boxes at home and the nooks and crannies around my garage. So I was able to be a part of that as well.

[Chelsea Benson] That’s really interesting. So as you pointed out, Robyn, people and yourself are seeing more bird behavior. And one of the things that I really wanted to focus on during our talk today is how do we learn what our common backyard birds are? And the nest and eggs that we might find?

So, Holly, I would love if you could spend a few minutes helping our audience learn where even to look for bird nests. We’re going to talk about nest boxes in a minute. But let’s focus on open cup nests. And where should we look? What clues should we keep in mind as we’re exploring?

[Holly Grant] Yeah, absolutely. So as many of you may know, nests are notoriously difficult to identify. But finding them– the birds are trying to find a spot to put their nest where it’s going to not be seen by predators. It’s going to be hidden. So sometimes, it does take a little bit of effort to find them.

Some of the most common places you can find a nest around your house are on porch eaves. If you have a front porch, and you’ve got some nice flat areas up near the roof, you might see a phoebe or barn swallow nesting up there.

If you’ve got planters, might see a bird nesting in the planters or nearby bushes or shrubs. So those are pretty common for around houses. But each bird has its own habitat that it prefers to nesting. So that can be a really good clue when you’re starting to narrow down the species.

Combine that with the region of the US that you’re in. Or region of the continent or wherever you are. Where are you? What kind of nest it is? Is it a cup nest?

Or like Chelsea said, later we’ll talk more about cavity nests that could be found in nest boxes. And then also the surrounding habitat. Not just where the nest is located, but what is it like in the surrounding area near that. So a bunch of really good things to look for.

And then another way to help you find nests is by just observing the birds in your backyard. So during the springtime, when a bird has a nest, it’s going to be going back and forth from wherever it’s grabbing food and bring it back to the nest to feed its young.

So if you’re just watching the birds, and you happen to see one that keeps going back to this one spot, that might be a good spot to start looking for a nest. Because that bird is very likely bringing continuous amounts of food back to its hungry nestlings.

But we also have another– I can show you on our website here a spot that’s got more tips on how to find nests. But I think we want to take a look at our common nesting birds tool too, right?

[Chelsea Benson] I would love– yeah. Could you pull that up? Because I think this is something our audience is going to find really helpful. As we’re seeing people from all over, it’s helpful if you have some way to narrow down. And this tool from NestWatch really helps you narrow down and pinpoint what you might have found. So if you could share that with us, that’d be great.

[Holly Grant] Yes. I will share my screen. All right. So can you guys see this, all right?

[Chelsea Benson] Yup.

[Holly Grant] All right. So this is the NestWatch website. We’ve got a ton of resources. So what I’m going to show you right now is under our Learn tab. It’s called common nesting birds. So when we go here, this just shows a nice list of possible species that would be nesting around you.

So it’s not going to cover every single species in the continent. But it’s going to be the ones that are most likely to be found near– the easiest to find I should say. Not necessarily, near humans, but the ones that are most easy to identify for us.

So what you can do is use these four filters at the top. Again, it’s region, nest type, habitat, and substrate. So let’s start on the first one here. So if we were, let’s say, on the East Coast, and we saw a cup-shaped nest. And click Cup.

And then the surrounding habitat, let’s just say, you’ve got a lake nearby. Maybe you’re at your lake house. You have seen a cup nest. You’re near your lake house. And– oh, well, there’s only one that pops up there. But you can also look at the substrate. And let’s say it was built on a building.

So you’re on your porch of your house that might be next to a lake or a pond. And the most likely species that we have is a barn swallow. And if you look into the species page, we’ve got a whole bunch of helpful information. So we’ve got a nice picture.

On the right here, we’ve got examples of the nest. So if you saw a nest that looked really similar to this, this is probably the species that you saw. You can scroll down. See examples of eggs. With a nice little ruler so you can estimate the size.

And we’ve got I think more. This one’s got quite a few examples here. You can see what a general barn swallow nest looks like. It’s, well, made with mud and bits of straw. It can be sometimes lined with feathers.

And lower on the page, you’ve got when to look for the bird. So barn swallows generally start nesting– it looks like– from May through mid-September. We’ve got a map showing where they nest. And then the different kinds of habitats and substrates that they’re most likely seen on.

And then down here, we’ve got the typical clutch size. What height you might find that nest– most normally find it at. And then how long it’ll take for those eggs to hatch. And how long it will take for the young to fledge. And more useful hints in the bottom. So chock full of information.

Now, if we go back, I’ll show you how to get to a few others here. So eastern phoebe is a really common one that people find on their porches, or back decks, usually, up under the eaves. They normally live in the east. They have cup nest. You’ll find them, I think, it’s near grassland or open habitat, and then on a building.

So you’ll see eastern phoebe pops up right here. Again, if I click on it, you can see it’s got nice white eggs, and a few examples of the nest. I think this one is a really good example. They normally have this outer layer of moss, which makes them very identifiable.

Let’s see. I think we wanted to go through a few more. Right, Chelsea?

[Chelsea Benson] Yeah, if you want to do one more. Maybe pick a western species?

[Holly Grant] Yeah, absolutely. So we’ll start with western here. And like you can see on these nest types, so we have cup nests as well as platform nests and cavities.

So let’s do a cavity species here in the west. And maybe you’ve seen it near some open woodland. And maybe you found this one on nest box. And here, you’ve got all of these possible choices.

And for folks that might not be completely sure, you can click on to each of these. See those pictures, compare to the one that you’ve seen in real life, and whittle your choice down from there.

So in this case, I was thinking of a western bluebird. So you can see we’ve got more information here. They make nice grassy nests and have pretty plain-looking eggs. And there’s a nice little picture of the nestlings. All right. So I’ll stop sharing now.

So it’s a really great tool for people who are stuck at square one. They’re not sure where to go. You can use our common nesting birds tool to whittle down your choices. And then if your nest still isn’t matching something that’s on that tool, feel free to take a picture and send it to us.

We’re more than happy to help you identify a nest. And including information, such as where you found it, what the eggs look like, if you happen to see the adult nearby. Those are all really helpful attributes that can whittle our choices down even further.

[Chelsea Benson] That’s great. Thank you so much. And that’s really a good segue because you ended on cavity-nesting birds. And I would love it, Robyn, if you could talk about nest boxes and our typical inhabitants of nest boxes.

[Robyn Bailey] Great. So with nest boxes, I think you’ll find that it’s a little bit easier to use that same process of elimination to get to what the most likely species is in your particular nest box. Because the number of birds that will nest in a cavity or a simulated cavity, like a nest box, is much smaller. So we don’t have as many options to whittle down and that’s a great place to start for the process of elimination.

I did create a slide that I would like to show you that just has some common examples. Again, it’s by no means, every possible nest box bird. But I have some common ones that you’re likely to encounter. And I’ll just pull them up here.

And hopefully, you can see. I’ve got a slide here for Common Nest Box Occupants. So that’s not a piece of our website. This is just a slide that I made. Give me a thumbs up, Chelsea, if it’s showing up for everyone now. Great.

OK, so the first thing I do when I find a nest and a nest box– or occasionally I find them in a tree cavity– is to think about the nest material and the color of the eggs. Those two things alone can be really diagnostic for which particular species might be in your box.

If you find a nest that is packed full of twigs and has some feathers, and maybe even a little piece of snakeskin or cellophane plastic in it, that’s a really good sign that you’ve got a house wren nest. They have these wonderful, very small eggs that have these nice cinnamon-colored spots. Often, some spotting around the larger end of the egg is more common.

That’s a pretty good indication of a house wren. It’s a tiny little bird that sings a really loud song. And they usually start nesting after other birds have started nesting. So if it’s later in the season, and the box is packed full of twigs, I go to a house wren as my first choice. And then from there, I can think about other diagnostic factors.

Speaking of the box being either packed or not so packed, that’s a good thing to keep an eye out for as helpful as the nest box. Eastern bluebirds and tree swallows typically only build a nest that’s a few inches deep. It rarely fills the entire box. I have seen that happen where they build it right up to the top.

But generally speaking, I don’t see that as much. So it’s a shorter nest. A little bit easier to see into. And we’ve got very different egg colors. The grassy nest underneath can look pretty similar, but the egg color is very different.

Bluebirds– whether it’s a western, mountain, or eastern bluebird– they’re going to lay blue eggs for the most part, unless they have a genetic mutation that causes them to lay white eggs. And there’s no feathers in the lining of that bluebird nest.

Tree swallows, on the other hand, will always lay white eggs and have that beautiful fluffy, feathery appearance to the nest. And again, we can generalize this tree swallow nest to other species like the violet-green swallow, which makes a very similar-looking nest and lays very similar eggs.

I’ll move down in a clockwise direction. Chickadees on the other hand, if I open a nest box, and I see a packed full of green moss– and again, it’s a pretty shallow nest– I know right away it’s a chickadee. Up here, it would be a black-capped chickadee.

In the south and out West, it would be different species of chickadees. But their nests look very, very similar– always a green, mossy, cozy, cushy-looking nest. Kind of feel like you want to stick your fingers in there because it’s almost always lined with deer fur or rabbit fur, something really soft. So it’s the one that I think I would like the most if I was a bird.

And, of course, the funny thing is that the babies really look like chickadees. They look very much like the adults. So they’re not as difficult to identify. The egg color on those chickadees is going to be pretty similar to the house wren– a creamy base with some reddish, brick red, cinnamon-colored spots.

Moving on, another common occupant is the house sparrow. They will usually fill their nest all the way to the top of the box and tuck their eggs deep in there. That’s why this photo is so dark because it’s hard to look into a house sparrow nest. Because they’ve usually built it up pretty high, and they stuff it full of things.

It looks messy because they tuck in bits of feathers, garbage, dried leaves. I’ve seen landscaping mesh, all kinds of things in there. So it doesn’t have that tidy look that you would see with some of the other birds that make a more compact cup-shaped nest. It almost has a dome over the top.

And then just for fun, I threw in this mouse nest. Because this is a question that we get asked a lot is– what bird made this nest? And you’ll notice with mice, it’s very common for them to fill the entire box with material and create this entrance hole through the side.

Most birds will not enter their nest straight in through the side. If you can imagine, if the door was on this box, that would be like flying right into the side. Usually, these are a top-down entrances. But the mouse will almost always put its entrance hole through the side of the nest and create a dome over the top.

And there’ll be many different kinds of materials in there, not usually one consistent material. Often, it’ll be very fluffy whether they found some goldenrod seed heads or pieces of a muff that was nearby. They’ll chew off little fibers from something that they found like an outdoor rug and stuff it in there. So something usually that looks cottony or soft will be in that nest.

And if it’s already been fairly well used, there’s usually a smell of ammonia. So I would always go in and clean the box after a mouse has used it to get rid of that smell. So being careful with mouse nests, you want to be wearing a mask and not breathe in any of that material.

But these are just the common occupants. There are others. So certainly, this is not an exhaustive list. But as you can see from the slide, the things you want to take into account are egg color, the height of the nest, the predominant material, and the nest lining. So it’s often easier to look at in a static nest box than it would be to find that in nature.

[Chelsea Benson] Great. Thank you so much for sharing those tips with us. And I agree. The chickadee nest is the coziest-looking nest.


They’re just so fluffy and soft. So we spent a little bit of time here talking about nest boxes. And when we’re talking nest box and birdhouse, those terms are interchangeable for our audience. A lot of times– when we’re talking– we mean the same thing.

But we know that not all nest boxes were created equal. And there’s some things that make nest boxes better than others. And I know our audience is really curious about what makes a good birdhouse, like what should they be looking for. Holly, could you walk us through features of a good birdhouse?

[Holly Grant] Absolutely. Share my screen?

[Chelsea Benson] Yeah, if you could. There’s a really great graphic that I just love.

[Holly Grant] OK, and before we go to that too, I just want to put in a quick note. Just to clarify too. I think I saw one of the comments come through.

These cavity-nesting species are going to nest in nest boxes. And other species prefer to nest in cup nest. You’re not going to see very many species that will nest in both of those.

So I know there’s a lot of folks that might ask about if they can buy a nest box for hummingbirds, or cardinals, or other birds that most normally nest in cups. So nest boxes will not attract those species that normally build cup nests. Just to clarify that because I know that’s a question that we get a lot.

[Chelsea Benson] Yeah, that’s a good point.

[Holly Grant] Yeah, so let me–

[Chelsea Benson] Thank you.

[Holly Grant] So if you are going to build a nest box, let me walk you through our features of a good birdhouse tool here. That come through, all right?

[Chelsea Benson] Yep.

[Holly Grant] All right. So this tool is not necessarily a tool, I guess it’s the infographic here. We’ve got some really nice tips for keeping in mind when you build your nest box.

So first and foremost, we recommend using untreated wood. So sometimes, wood is pressure treated with fungicides or some other chemicals. It’s really best to just use the untreated, very plain wood. Often, cedar, or pine, or cypress are really good examples.

So for some of the larger boxes, like for owls, use a non-pressure treated, CDX, exterior-grade plywood. It probably doesn’t have to be exactly that kind. But again, just keep in mind this pressure treatment can sometimes imbue some chemicals that could be harmful to those nestlings that have just such delicate skin.

So again, galvanized screws. There’s some other options here. Make sure that the box has good drainage and good insulation. So as you can see here, we want to make sure that the roof is sloped. If your box design doesn’t have a sloped roof as part of that construction plan, you can mount the box at an angle.

So if you’re mounting it on a pole, just tilt it just a little bit. So that water and snow don’t build up on the roof there. And here, most of the non-pressure treated pine wood that you can find in big-box stores– it’s usually pretty affordable– it is that standard.

About 3/4 of an inch thickness, which is important for regulating temperature. If you go much thinner, those extreme temperatures can creep into the box and make it harder for that bird to survive. It’s really hot or it’s really cold.

Scrolling down further, we’ve got predator guards. So I’m not sure. I think we might go into this a little bit more later. But predator predators are a really great option. You want to make sure you don’t have a perch on your box.

That’s a very popular feature for boxes that you can buy from stores. And the perches actually make it easier for predators to reach inside. So we don’t recommend having those.

There’s several types of predator guards that you can choose. These prevent climbing predators from accessing the box. So snakes, squirrels, even chipmunks. Chipmunks are a surprising nest predator as well.

Let’s see. Farther down, we’ve got– making sure that the entrance hole is the correct size. For those who want to prevent European starlings, you want to make sure that that entrance hole is smaller than 1 and 9/16 of an inch. So that we’ve got here in this little brown half-circle. So anything smaller than that will attract things like bluebirds and swallows.

And then if you want to keep away house sparrows as well, it has to be smaller than 1 and 1/4 inch, which really only leaves you room for house wrens and chickadees. But those are some great ways to eliminate the chance of those species accessing your boxes.

But again, you want to make sure that the box is big enough to fit the bird that you’re trying to target. You don’t want to provide a hole that’s too small. And then these larger species can’t access it.

[Chelsea Benson] Could you just briefly mention why we might want to discourage starlings and house sparrows. Some people might not know about those species.

[Holly Grant] Yeah, sorry.

[Chelsea Benson] No, it’s OK.

[Holly Grant] Yeah so, European starlings and house sparrows are invasive species. They can usurp other bird’s nests, meaning, take over them while the other bird– like your bluebird or your swallow– might be in the middle of nesting, which can be harmful to those birds.

It is a good idea to prevent them from nesting. We have several different options on our website, which maybe we’ll talk about later. We’ve got some ideas for doing that other than this exclusion technique. We’re almost to the end here.

Another good thing to add in a nest box is a fledgling ladder. And that for a lot of boxes can just be a roughed-up area on the wood that’s just beneath the entrance hole. You can make some shallow cuts.

Or even just add some hardware cloth to the inside of the box. This is just going to give those nestlings a little bit of perches. So that they can get up and out of the box when it’s time to fledge.

And finally, you want to make sure that your box is easy to maintain. So we usually recommend about every fall, you want to clean out your nest box, get it prepped for the next year. So having a box with a door will allow you to clean it out a little bit easier. And completely take it apart.

And then I think we’ve got this tip here about having an extended back. Just makes it easier to mount on metal poles, which can– mounting it on a pole versus on a tree trunk can provide a better– Let me rephrase this.

A pole will be able to host predator guards better than a tree trunk. So if you’re looking to prevent predators from accessing those nestlings and eggs, it’s going to be a better idea to mount your box on a pole rather than on the tree trunk.

Because on a tree trunk, pretty much the only thing you can do is wrap some sheet metal around it. And that might not even prevent all of the predators that a predator guard normally would.

So we’ve got a lot of these. You can check it out on our website. Again, this is going to be under that Learn tab we’ve got here. Sorry, Learn tab.

[Chelsea Benson] Actually, while you have your screen open, just leave it there for a sec. One thing that people are asking like, is it too late to put up a nest box?

[Holly Grant] Oh, no. Absolutely not. So nest boxes– Do you want to go into the right bird, right house tool? Because —

[Chelsea Benson] Yeah, I would actually love it if you could share– So some people are now like– Oh, man, it’d be great to put up nest boxes. Is it too late? And how do I decide what nest box to put up? If you could help people just learn a little bit more about where to put nest boxes and what size of nest boxes. That’d be really great.

[Holly Grant] Yeah, so. Let me see. I think the best way to answer this is that it’s not too late to put up a nest box. But the best time to put them up is going to be in the fall. Because that gives them a chance to– the birds to get used to the box over winter. And then it’s going to provide a better chance of birds actually taking to those boxes this spring.

If you put a box up right now, it’s still possible you’re going to get a bird. But it’s less likely. It sometimes takes up to a year for those birds to really fully feel comfortable, and get used to the box, and consider it as a nesting space.

Anecdotally, we’ve heard too that when boxes are more weathered– they’ve kind of survived out nature for a while– somehow, that is something the birds like too. Maybe it mimics more what their natural cavities are like. So let me bring you to the right bird, right house tool. That’s all right on your end there?

[Chelsea Benson] Yes.

[Holly Grant] Because some of this information is on here. So this is similar to our common nesting birds tool. But this is just for cavity-nesting species or species that you can attract to a nest structure. So for example, mourning doves. They nest on this cone-shaped nest. And you can build a little cone out of some wire mesh to attract a pair.

So let me just explain this a little bit. Again, you just need to pick your region. So we’ve got Canadian and US regions right now. Hopefully, we’ll expand this in the future. But right now, this is what we’ve got. And I’m just going to go to, let’s say, the mountain prairie. And we’ll go to a grassland.

And if I click See Results, I’ll have– it looks like I’ve got nine possible species that could nest in my area, if I lived in the mountain prairie states, and had grassland near my house.

So I’m going to click here on American Kestrel. This will have a nice construction plan. You can download that for free. And use that to build a nest for the species. It’s got all the right measurements and everything all ready to go.

You scroll down on the page, you’re going to find a lot more helpful tips. So here, we’ve got a species in decline map. And for those that are familiar with this tool, you might notice we now show Canada as part of this tool.

That is a recent update from last week, actually. So pretty new. And we have updated this species in decline data to reflect– it’s a more recent data now. So it’s up to date.

Unfortunately, it’s a sad one, right? Kestrels are in decline over a lot of the continent. But one of the great things you can do for these species in decline is provide a nest box.

So as you scroll farther down, you’ll see more detailed information on where the ranges. You’ll see what kind of habitat you can place that box in, what it can be attached to, and there’s a known nesting period. Which goes back to that question you had, Chelsea about when did these birds start nesting, right?

So and even earlier, we talked about how owls are already starting nesting. Some of them already have eggs right now. But birds like kestrels, they’re not going to really start nesting until the end of this month. So if you want to try for it, you can build a nest box, install it next week, and then you might get a pair this year.

Again, it might take up to a year. But this is a really great section of this page here. They can help you estimate when you can expect to see birds using the box that you’ve put up, what time of year that they’re most likely to use it. In other words, let’s say, you put up this kestrel box, and it’s June, and you still haven’t seen a bird in it. You might have to wait until next year.

And then just scrolling down, a few other features here would tell you the best height to place nest box, the minimum spacing. I actually got several questions about this today, about minimum spacing. This is the distance between two boxes meant for the same species.

So if you put two kestrel boxes right next to each other, only one of them is going to get used. You have to put them at least a half a mile apart in order to get two pairs to use them. So that can require a lot of land cover. And I think that might be one of the contributions to why it’s in decline. Because they need so much space.

And again, we’ve got what direction the entrance hall should be facing. For kestrels, it’s anywhere. Southeast is usually good. And then we’ve got some general measurements. So ideally, the entrance hall should be about 3 inches in diameter, should be about 14 inches tall– the box. And then 10 by 11 and 3/4.

And then we usually have a list of helpful tips here. But there’s just one for kestrels. A little bit more advice on where to place the box. So this is a nice quick summary of it. And then I’ll just say too, at the top here, you can select another species from this list very easily. You don’t have to go back and search with the filters every time.

[Chelsea Benson] And then as you’re looking at that, there’s the big green button that says download the plan. So as you’re looking, if you’re like, oh, I’d love to build this one. Or I just want to see what it looks like, you can enter that, download the plan, and there it is.

[Interposing voices]

[Chelsea Benson] How many species? 59 or something like that?

[Holly Grant] I think we actually got it up to 60.

[Chelsea Benson] All right.

[Holly Grant] We just added a little shelter for common terns. So 59, I guess still. But it’s around that number.

[Chelsea Benson] That’s great. Well, thanks so much, Holly, for sharing that. We’ve been talking about a lot of resources on the website. And, Robyn, I would love if you could share some tactile resources. What are things that people could pick up and take out with them and use while they’re outside exploring?

[Robyn Bailey] Yeah. If you’re a person like me who really likes to just have something to reference on hand, I definitely recommend these two guys. They’re very light reading. So it’s not too intense. And the idea is that it would get you down to the relevant species a bit faster.

So this is our guide to nests and eggs. I know that’s a little bit hard to read. But we’ll pop the link into the chat. And this one is just some common species that you’re most likely to find. We have a similar one called, Right Bird, Right House, which shows a lot of the same information that Holly just shared.

And then if you think you’re really into finding nests that are a little further afield or you have some unusual birds, I have other two physical books that I like to turn to. There’s a Peterson guide– this is eastern, but there’s also a western one– to birds’ nest. That’s a great resource

And I also like– this is a bit of a heavier read. But this is Nest, Eggs, and Nestlings of North America. And I really like that one for identifying trickier nests, like maybe grassland species that we really need to pay careful attention to the egg color, and the nest material, and placement. So those are some physical resources.

And we do have a fun surprise for you. We are going to be giving away 10 copies each of these laminated guides, which are great for you to stick in your pocket or backpack while you’re birding. And there will be a follow-up email– after the webinar– explaining how to enter, and the restrictions on entering the guidelines– for the giveaway. And that’ll come in an email. So watch out for that. And I hope that you’ll enjoy those if you’re one of the winners. So keep an eye out for them.

[Chelsea Benson] Oh, I’m excited. Can I enter? I think that’s a restriction.


So, Robyn, I see a lot of people are asking about cleaning out nest boxes. So Holly kind of touched on. It’s best to do it in the fall. But we forget to do it. And now it’s spring, can we do it now?

[Robyn Bailey] Yeah, that’s a really good question. Whether or not the birds have already started nesting near you, it’s going to be the key thing to think about when you approach a nest box. If you feel that you haven’t really kept a close eye on it, I would say give it a check and keep an eye on it.

If there’s a nest in a box that seems flat– as if the weight of several nestlings has compressed that material– and there are some fecal material in there, it’s a good chance that it’s a very old nest. And you can go ahead and clean it out.

If you find a nest that looks fresh with eggs in it, I would say don’t clean it out, leave it alone, keep an eye on it. And make sure that’s not a brand new nest before you clean it out.

Up here in New York State, I know we’re pretty safe. And I plan to clean mine out relatively soon. Because I know the birds don’t usually start this early in the year. So it comes a little bit down to where you’re located and what your birds are doing.

But always approach any nest with caution. And before you clean it out, make sure you feel like you know what’s going on inside. But it’s not too late up here for us, for sure.

[Chelsea Benson] Yeah, yeah. So it seems like check it for activity, and then you can look in the box. And if it looks like old, soiled, yank it. But if you’re seeing new material on top, best to leave it because that’s probably an active nest. OK, that makes sense. Thank you.

We’re going to jump into Q&A real quick but before we do, I just wanted to touch on predator guards because Holly had mentioned that it is important to add a predator guard. And she talked a little bit about what common nest predators are. But are some guards better than others? And what’s NestWatch tell us about guards?

[Robyn Bailey] Great question. So we looked at this recently with data submitted from NestWatchers all around the US and Canada. And we had thousands and thousands of wonderful citizen-science observations that we drew on to answer that question. And the answer– to make a long story short– was really that predator guards are beneficial. They can help a nest get from nestlings to fledglings and succeed when there’s a predator guard on there.

The reality check for me was that they were really all about the same. I didn’t expect that. I thought there might be a clear winner. Instead, what we saw was that they were all relatively effective.

Of the three that Holly pointed out and which are available on our website, I would recommend either the stovepipe baffle, which is a cylinder, the cone, or that little wooden block that you can put over the entrance hole to make the entrance hole a little bit deeper that’s going to help keep raccoons and other birds from reaching in through the entrance holes.

So those are all available on our website. And thanks to NestWatchers, we were able to show that they can give your birds about a 7% boost in likelihood of that nest fledging. Which is pretty big. It doesn’t sound like a lot. But it’s actually a pretty good boost.

[Chelsea Benson] That’s really great. And I think it’s a good example of how people, like our audience, has contributed to this research. So people were reporting cavity-nesting birds, and whether or not they had a predator guard. And with that, you were able to get this data set. Is there any other new and outcoming research that has come from NestWatch that you’d like to clue us into?

[Robyn Bailey] We’ve been working on a number of different things from invasive species to supplemental feeding of nests. I can’t give anything away right now. But one thing I’ve been working on in the last couple of weeks is our study that we’ve been undertaking for several years.

And looking at feeding bluebirds and chickadees, does it actually help their nest survival? Does it help increase the number of eggs that they lay? Or does it make them nest any earlier than they would if they weren’t being fed?

So there are many questions related to that that are up and coming. And I’m really excited to be working on. But nothing on fresh ink yet. It’s all still in production. So–

[Chelsea Benson] Well, the nice thing is–

[Robyn Bailey] –lots of good question.

[Chelsea Benson] The NestWatch website has a blog. And I know that you and Holly both do a really good job of sharing the latest research on that blog. So for our audience, if you go to NestWatch there’s a whole link for the blog. And I encourage you guys to follow that. Because I find all kinds of great info from those post. So thanks for doing those for us.

All right. We have so many audience questions. And my co-worker, Leo, is behind the scenes frantically trying to answer as many as he can. Some of our audience live in really warm climates. And they’re asking about like, is it OK to paint a nest box? So does it absorb as much heat? Or are there any tips for reducing the heat within a nest box for birds?

[Robyn Bailey] That’s a really great question because there actually are not many studies. I can’t think of any really broad studies that have been replicated a number of times that would answer that. So as a precaution, we say not to paint nest boxes. If you do paint them, paint them in neutral color that helps them blend into their surroundings and use the least VOC or the least toxic paint that you can find.

But generally speaking, we prefer that they be unpainted. With the exception of purple martins, which do almost they are very attracted to artificial housing and these bright white structures that people place for them to nest in. And they seem to be attracted to that white color. So with the exception of purple martins, we best to leave them natural.

Another thing you can do to help cool the nest box is to place a really broad roof on the box. Maybe bigger than you would think is necessary. And that can help shade the box. And then not place it in direct sunlight. If you can find a shadier part of the yard, the school campus, or the golf course to put it, that can certainly help keep that direct sunlight off of it.

[Chelsea Benson] Great. Another question that’s coming up. We did talk about cleaning out nest boxes. And for the most part, good idea because it can build up like well, birds are not messy in the nest when they get older. So they get a little soil. So good to clean those out. And sometimes they can have parasites in them.

But what about a phoebe nest? Or a barn swallow? Or a robin? Those open cup nests that we find, do they reuse those? Should we leave them be?

[Holly Grant] This is–

[Robyn Bailey] Go ahead, Holly.

[Holly Grant] OK. Just going to say, this really does depend on the species. Some species will readily reuse their nests. And other species won’t. So generally, in the season right within that same summertime period, you can probably just leave those nests as they are.

In the fall is a good time to remove nest that are in areas that maybe you don’t want to continue to encourage that bird to nest. Or if the nest is maybe over a lights off it, or something like that. You want to make sure you wait until after the breeding season is over with. Just in case– whichever bird species that is– comes back to do more broods.

It’s not the end of the world if you remove it in the season. But it’s really important to make sure that that bird is done nesting. There’s no breeding activity at the nest when you do remove it. So that’s why we usually say err on the safe side. Wait till the end of the season

It won’t necessarily hurt the bird. In terms of let’s say, for a nest box, you want to clean the nest in between broods. That’s possible, again, as long as you’re making sure there’s no breeding activity.

And, for example, eastern bluebirds. It doesn’t matter to them whether the nest is cleared out or not. But that is more time that they have to spend rebuilding that nest. When they might have otherwise just laid eggs in that nest that they’d used just a few weeks prior. Do you have anything to add, Robyn?

[Robyn Bailey] Maybe just I’ll chip in that a few other species are more inclined to reuse their nest year after year. We see that very commonly with American robins, barn swallows, eastern phoebe, and out West states phoebe.

In fact, I’ve had robin nesting on a kiosk at a trail that I visit frequently for the last several years. And you don’t think that they’re going to reuse that nest. And then you peek in there, and sure enough, there’s eggs in it again.

So it can be a good idea sometimes to leave those nests and just see– if it’s in a spot where it’s not in harm’s way, go ahead and leave it. And see if the birds come back to it the next year. And if they do, then you can more easily nest watch it.

If it’s in a bad place, what I suggest is creating like a little nest shelf or structure that you can create– we have plans for on the website– to encourage them to go a little bit further away. Maybe from your front door or over the staircase that you use. That you can help guide them away from a bad location if they’re in an inconvenient spot for you.

[Chelsea Benson] And I think something that’s really important for us to point out is if it is nesting, and it’s in a bad location, and there’s eggs in the nest, then what’s the advice from NestWatch?

[Holly Grant] Ideally, you want to leave that nest where it is until those young fledge. Once eggs are laid, those nests are federally protected. So moving a nest at that point, not only is against the law.

But it’s because moving the nest can cause the adult bird to abandon it. They may not see where you’ve moved it. They might not be able to find it again. So that results in just a failure of the nest.

So it’s really unfortunate, especially if you’ve got a building project that you want to start up and there’s a bird nesting. But probably best to leave it as is.

[Chelsea Benson] Wait a few weeks.

[Holly Grant] Yeah.

[Chelsea Benson] Are there any tips for checking nest that maybe we can’t see? Do you have any tips for whether it’s way too high or just in a crevice? What do you suggest?

[Robyn Bailey] I always have a mirror handy when I go looking at nests. Whether it’s just a little pocket mirror that I can reach the nest and peek into. It’s really good to just hold that mirror up and count eggs or young in the reflection. I also have a little mirror that extends several inches for those nester. Just out of reach. This is something that is very inexpensive to use.

I can also use my phone with the camera feature and the flash turned off to snap a picture of a nest that’s just over my head. If it’s really far out of reach, and it seems like it’s just going to be difficult to nest watch it, we suggest just grabbing your binoculars or a camera and trying to monitor it from the ground.

Don’t try to climb a tree or do anything extreme to monitor a nest. Your own safety and that of the bird’s is the first priority. And data on, for example, an osprey nest where you can see that a female is incubating and feeding young. That’s just as good. So don’t feel the need to do anything extreme to get to a nest. So we have a couple of tools in our tool belt. And there are some suggestions on the website. Maybe Holly has some more.

But if you can’t reach a nest with the tools that are available to you, certainly, don’t put yourself on a stepladder, doing something precarious to try to get to it.

[Chelsea Benson] Some people are saying that they live near a nest box trail. Is there any way for– what’s the best way to monitor those nest boxes that are spread out amongst the field?

[Robyn Bailey] Hm. I’m going to interpret that question as those boxes are–

[Interposing voices]

[Chelsea Benson] They know who owns them. Is there any specific way, that–


That’s a good question. That is also something we should cover. But is there a way for groups to participate that are monitoring a trail? That’s how I should ask that question.

[Robyn Bailey] Yes. Of course, making sure we have permission to access the land of a nearby nature center, or golf course, or school ground, wherever the nest box trail happens to be. If you’ve got permission and you know whose boxes they are. Certainly, can join NestWatch with your account that you may already have. Talk to the person that is stewarding or responsible for the nest boxes and find out if they’re willing to help monitor them.

People can nest watch as a group. We have nature centers all over North America and bird clubs and hobby groups that are nest watching as a group. And they split the responsibilities. So for example, if you can’t possibly check all 50 boxes or however, 100 boxes– some of them are quite large– split those responsibilities with several other volunteers or staff people. And you can nest watch as a group. It’s called our NestWatch Chapters Program. And that’s available if it really is a large nest box trail.

And sometimes, you just take ownership. I’m on a couple of trails here in upstate New York. And we’ve just got permission. I put boxes out and monitor them. So you can take ownership to and put up your own trail if you don’t have one nearby.

[Chelsea Benson] That’s great. And so one thing I want to remind people is if they’re finding nests or they’re monitoring nest box, to enter that information through the NestWatch website. Or you guys have a mobile app– a free mobile app. They can download the mobile app and enter their nest boxes. It does require a username and password to login.

But if they’re already a member of any project at the Cornell Lab of Ornithology, they’ll use the same login. Right, Holly? Is that how it works? Holly is like the tech guru.

[Holly Grant] Yup, yup. So if you are a member of eBird, or FeederWatch, or any other Cornell Lab projects, use that same username and password. It’ll get you right into And then you can use your data tab to start exploring ways to submit your data to us.

[Chelsea Benson] Great. Thank you so much. We are right up at 1 o’clock. So I want to thank Robyn and Holly for taking the time to share this information with us. That was really fabulous.

And then, I want to thank– yeah. I want to thank our audience too. We have such a great audience, very active. And I apologize that we barely dipped into all your questions. If you have lingering questions about the Lab of Ornithology or about birds, in general, you can email And if you have questions about NestWatch and nesting birds, Holly will take your questions–

The webinar today that we’ve done is it’s part of a series. We’ve been highlighting Lab programs, and helping you– our audience– learn about the birds around you. The webinars are free. And they’re available to anyone. And if you’ve enjoyed today’s program, I really encourage you to participate in NestWatch. And also become a Lab member. Our Cornell Lab members support NestWatch and they support all the programs that we feature during this webinar.

For everybody that’s been watching, I’m going to be emailing out a recording of today’s webinar. I’ll include all the great resources that Robyn and Holly walked us through on the website. I’ll include the link to enter the giveaway. And a link to download your own nest box plan. Lots of great stuff will be sent your way, probably, by tomorrow afternoon.

So again, Holly and Robyn, thank you so much. Good luck with the nest watch season.

[Holly Grant] Thanks so much.

[Robyn Bailey] Thanks.

[Chelsea Benson] And thanks to our audience. And have a great day everyone. Bye.

End of transcript

Have you ever found a bird’s nest you couldn’t identify? It’s both an exciting and puzzling moment! On March 2 at 12 p.m. Eastern, join our conversation with NestWatch Project Leader Robyn Bailey and Project Assistant Holly Grant as they share tips and tricks for identifying common backyard nests and eggs. We’ll discuss how to safely monitor nests and baby birds and reveal features of a good birdhouse. Discover how you can turn your observations of nesting birds into scientific data with NestWatch.