Thumbnail image Brian Calk | Macaulay Library

[BIRDS CHIRPING NOISE] [Alli Smith] All right. Welcome, everybody. Thank you so much for joining. My name is Alli Smith. And I’m speaking today from the Cornell Lab in Ithaca, New York. And today, we’re going to celebrate the incredible milestone of 2 million sound recordings archived in the Macaulay Library. Over the next hour, I’ll be joined by colleagues from the Cornell Lab and from sound recordists from all around the world to give you a tour through the history of the Macaulay Library, learn about sound recording in general, and highlight some of the amazing recordings within this collection and the people behind them. I have a couple of tech notes before we begin.

Tonight, we’ll be streaming this webinar on both Zoom and YouTube. Feel free to use the chat to ask us questions. We will have time to answer them on camera. But we do have moderators from the Cornell Lab who are ready to answer your questions in the chat. And they’ll be able to type out some answers for you.

Closed captioning is available on Zoom. If you’d like to turn captions on or off, you can click the captions button at the bottom of the screen. And then finally, this webinar is being recorded. And we’re going to post it on YouTube later this week if you’d like to watch again or share with anybody else.

To start off this celebration, I want to introduce you all to the current director of the Macaulay Library, Dr. Mike Webster, who’s going to give us some background about why birds sing and about the Macaulay Library. Mike, thank you so much for joining us today.

[Mike Webster] Great. Thanks a lot, Alli. It’s great to be here. And I’m thrilled to see so many people showing up from all parts of the world to celebrate sounds with us. So let me quickly start my screen sharing here. OK, great. There we go.

OK. So I guess the first thing that I want to say is that people have been out there in nature recording the sounds of birds and other animals for decades. And since it began in 1929, the Macaulay Library has collected and curated and preserved those recordings. The size of the Macaulay collection has grown over the years, in particular once we partnered with eBird, which allowed people to directly upload their recordings to the archive.

And thanks to all that growth, the Macaulay collection– the archive has grown substantially. And just this past fall, in October, we hit a very significant milestone, as Alli already mentioned, when we archived the 2 millionth recording. That 2 millionth recording was of a yellow-browed tody-flycatcher recorded by Marcelo Barbosa in Para, Brazil. And tonight, it is my very great pleasure to play that 2 millionth recording for all of you.


OK, great. So a wonderful recording captures the voice of that little, tiny tody-flycatcher. And that recording, along with about 2 million others, are in the Macaulay Library now along with tens of millions of photos and thousands and thousands of videos.

In the early days, the audio recordings were stored on magnetic tape. And this photo here shows some of the Macaulay team in our storage room with some of those tapes showing them off. But reaching 2 million recordings was really made possible by changing technology, technology that allowed people to record digitally and to upload those recordings, and, for us at this end, to store the digital copies.

2 million recordings is an outstanding number. It’s an astounding number. And I have to say, I honestly never dreamed that the collection would grow that large, certainly not in the time that I was here. And thinking about that number probably raises questions for a lot of you, questions like, why do we even need sound archives? What are they good for? Why do they exist?

Sound archives exist because each recording in an archive is an incredibly valuable piece of scientific data. Each recording captures the sounds of a particular individual bird at a particular place and a particular time. And so these recordings capture variation in the sounds of birds over individuals and across space and across time.

And those sorts of data are incredibly valuable to scientists doing research aimed at a better understanding of the natural world. They’re also valuable– oh, sorry. So science– and they’re also valuable for conservation efforts, for example, by enabling acoustic monitoring of threatened habitats.

Recordings like these are also useful for educators teaching science classes at all levels. And they’re even valuable to artists that want to incorporate the sounds of nature into their work. So that’s why we exist.

But another question some of you might have is, why 2 million recordings? Do we really need that many? Does the Macaulay Library really need over 14,000 recordings of a single species, the song sparrow? And after all, once you’ve heard a few recordings of song sparrows, you kind of know what that species sounds like.

But the reality is that the sounds the birds make are incredibly varied. They’re incredibly variable. There’s variation not just between species but across populations and across regions of a single species.

And even within a population, there’s a lot of variation between individuals– so males versus females, young versus old. And even within an individual, most individuals don’t have just a single song. But they have an entire repertoire of song. And they also have– on top of their songs, they have calls or alarm calls, warning calls, contact calls, begging calls.

And their vocalizations might even vary with weather or ecological conditions. So there’s a lot of variation out there. And to study that variation and to understand why it exists, to decipher the language of birds, and to train computer models to identify and monitor birds, we need a lot of recordings.

Then some of you might be wondering, why do birds make sound at all? The answer to that one is actually pretty simple. Birds use sound as well as their plumage color and physical, flashy displays to talk to each other.

They use sounds to defend a territory, to call others to food, to warn of approaching danger, to attract a mate. Birds vocalize for a whole variety of reasons. And birds are really exceptionally noisy animals, much more so than mammals or insects or most other animals you think. Birds make a lot of noise.

And so a large and growing sound archive, like the Macaulay Library, is central to deciphering the sounds that birds make. It’s central to understanding why and how birds make the sounds that they do. And it’s central to helping preserve birds so that they continue to sing.

But there is also one other reason why the Macaulay Library exists. The Macaulay Library exists because those of us who can’t actually travel to Brazil can still go to the Macaulay Library and hear what a yellow-browed tody-flycatcher sounds like. The Macaulay Library and other sound archives– we are here to share the sounds of birds and other animals. We’re here because the sounds the birds make are simply amazing.


And so what I want to do just for a couple of minutes here before we move on is to share and celebrate some of those amazing sounds the birds make. For a lot of people, it’s fun and sort of educational to see the songs, see the sounds, as well as listen to them. And scientists do that with something called the spectrogram.

And so here’s a photo of a song sparrow and a spectrogram of a song sparrow song. And a spectrogram is just a visualization of sound where the x-axis, along the bottom, is time. And pitch or frequency is along the y-axis on the side. And each blob in this picture, the sonogram– the spectrogram here is a note that the bird’s uttering.

And so I look at the spectrogram. I look at a lot of these things. And so I can look at this. And I can see it’s– this bird sounds like high note, low note, high note, low note, high note, trill, buzz, whir. And so let’s hear what it actually sounds like.


So high note, high note, high note, trill, buzz, whir. To really appreciate it though and help train your eyes and your ears to work together, it’s useful to slow that song down. And so I’m going to play it again at half speed. And follow along and listen to the high note, high note, high note– or low note, high note, low note, high note, trill, buzz, whir with both your eyes and your ears.


So that’s the song of the song sparrow– a song of a song sparrow. And what I want to do now is just play a few more songs of different birds. I’m going to show a moving spectrogram.

So it’s a moving spectrogram. And you can follow with your eyes as you’re listening with your ears to each of these birds. So we’ll start with a wood thrush.

So this is a common bird that sings up here in the Northeastern US during the spring. And it has a beautiful flute-like . Sound and so here is the song of a wood thrush.


And again, to really appreciate it, we’re going to slow it down now. And you can see how intricate and otherworldly the sound really is.


So if you’re practicing– listening with your ears and watching with your eyes.


I love that one. So another bird, a crested oropendola– oropendolas have a soft spot in my heart. I did my PhD dissertation work on oropendolas. I love them for many reasons. But one of the reasons is they just have amazing voices. They make sounds like no other bird can. So here is the sound of a crested oropendola.


Amazing. It doesn’t even sound like an animal. So to really astound you, I’m going to slow it down. And just pay attention to what this sound is– what this bird sounds like.


Utterly amazing. So I hear that. And I wonder not only what is the bird saying, what message is it conveying, but how does it make that amazing sound? It’s like plucking down a harp. OK, one last one. We can’t talk about birdsong without talking about the new world wrens. They are true songsters. They make amazing sounds. Here is a Pacific wren.


And again slowed down.


That is just utter jazz improvisation. It’s just amazing that that little bird can make those kinds of sounds so rapidly. So listening to those amazing sounds, that was made possible by just a few of the very many dedicated recordists that have recorded the birds that they see and then have submitted their recordings to the Macaulay Library.

And in closing, I just want to extend my very, very heartfelt and sincere thanks to those many contributors. And with that, I’m going to stop my screen sharing and turn it back over to Alli. Thanks, Alli.

[Alli Smith] Awesome. Thank you so much, Mike. That’s really cool. I love seeing those spectrograms in slow motion. That really shows how incredible these birds are.

So we made it to two million recordings. And that’s an incredible milestone. But it’s taken a really long time to get there.

And right now, I am physically in the Macaulay Library in the collections room. You can see all the shelves behind me that are filled with thousands and thousands of physical tapes of sound recordings, going all the way back until the 1930s. And this room really represents the full history of the collection.

And over here, we have Glenn Seeholzer, who is going to join us today to talk a little bit–

[Glenn Seeholzer] Oh, hello.

[Alli Smith] –to talk a little bit about the history of sound recording. Take it away, Glenn.

[Glenn Seeholzer] Yeah. Hey, everyone. Welcome to the Macaulay Library or at least the physical side of it. The question that we should be asking ourselves is, what’s the oldest sound recording in the archive? We have two– there’s two actually. It’s a tie for first place for the oldest.

Here, we have a song sparrow. That was recorded by Arthur Allen and Peter Paul Kellogg on 18th of May 1929 in Stewart Park, right here in Tompkins County, New York. And let’s listen to this because that take us back almost 100 years back in time.

SPEAKER: LNS catalog number 16737.


[Glenn Seeholzer] And then recorded shortly thereafter or in the same outing is this rose-breasted grosbeak. Let’s take a listen to that.

SPEAKER: LNS catalog number 169168.

[Glenn Seeholzer] Imagine what it was like to record this bird.


[Glenn Seeholzer] The faculty is recording on film.


Thanks, Alli. So that really takes us back. And what we’re going to do for the next couple minutes is actually talk a little bit about the history of sound recording. And I’m going to tilt this up so you guys can see me a little better.

And so these recordings were made not by one person but by a team of people because the equipment at the time was so heavy and bulky that you really needed a team to operate it. Here’s an example of what a team might have looked like. That’s actually Peter Paul Kellogg there, the older gentleman on the ground doing playback for one of the other key contributors to the ML collection, Randy Little.

And they were using equipment much like this reel to reel– where they’d spool reel to reel magnetic tape, often hand-cranked to get it started, to make these recordings. And so these two men were some of the pioneers of the field of bioacoustics. Oh, yeah, and they’re using things like this. So you can definitely imagine how you need two people to get these recordings back in the day. I’m going to throw that over there.

And so that was the start of the Macaulay Library, which was at the time the Library of Natural Sounds. And Arthur Allen and Peter Paul Kellogg went on to found the Cornell Lab of Ornithology. And they were really some of the pioneers of bioacoustics, basically popularizing the field that we all now is used in so many different contexts.

And so thanks to their efforts, we now have a representative– thanks to the efforts that they started, this basic field of bioacoustics, we now have representative recordings of nearly all bird species in the world. And we all have them now right at our fingertips in the Merlin Bird ID app.

But now we’re going to think about how we got to that point, how from a century ago we’re getting our first recordings of a song sparrow and a rose-breasted grosbeak, to now having representative recordings of all the birds of the world. What was that process like? And what was it like trying to build that collection?

And so think back to a time not too long ago when the vocalizations of almost all species outside of North America and Europe were unknown except, in some cases, the local inhabitants of a region. But they’re almost certainly undocumented by recordings. And so there’s not any living memory of what it was like to– what the experience was like of learning the soundscape of the North American avifauna with no resources or references like we have today.

But today, we’re going to be joined by Mark Robbins, who was a key contributor from the generation of neotropical ornithologists who document the sounds of the South American and Central American avifauna for the first time. Mark is the outgoing collections manager of the Department of Ornithology at the University of Kansas Biodiversity Institute and one of the most prolific contributors to the Macaulay Library audio archive, with almost 14,000 audio recordings representing 2,728 species from 31 countries.

He spent a lifetime in the field sound recording, using all generations of technology. And so he’s going to share some of his memories from that time, when he was just getting started. So, Mark, why don’t you join us? You can turn your video on.

[Mark Robbins] Yeah. Good evening, everyone. Thank you for the introduction, Glenn.

[Glenn Seeholzer] Yeah, thanks for joining us. And so to get the conversation started, we’re going to listen to a recording you made in 1983 on the Rio Manatee on the South bank of the Amazon River in Peru. And I believe I need to share a screen. Desktop 2. OK. So let’s listen to this.

[Mark Robbins] LNS catalog number 37513.


We’re listening to is that distant, repetitive slow mo sound. You can also hear a wall of insect noise, some of the feedback from the microphone.

[Glenn Seeholzer] And so, Mark, could you tell us a bit about this recording– when it was made, how it was made, what was it like making the recording?

[Mark Robbins] Well, as you noted, there was quite a bit of background noise– a number of insects, frogs. And at the time, that was made free dawn. And all I knew at that time was this bird was up in the subcanopy. And I had no idea what it was.

And as you pointed out, at that time, there was no Merlin. There was no online. There were no resources. And so you had sometimes spend days attempting to determine what a species was until you could actually see it.

In this particular case, I left the field there in Peru in August of 1983 not knowing what that vocalization was. And I sent my recordings to Ted Parker, who was one of the experts at that time. And he goes, well, that’s a collared puffbird. And that’s how I figured that out because I could never track the bird down in the canopy because it was always singing when it was fairly dark.

[Glenn Seeholzer] And so who’s Ted Parker? Can you tell us a little bit about him? He’s a super important figure in the field of neotropical bioacoustics and ornithology.

[Mark Robbins] I wish I had a couple of hours to answer that. But I’ll try to do it in just a few minutes. He was a legendary neotropical ornithologist.

At the time of his untimely death in August of 1993, when he died in a plane crash surveying birds in Southwestern Ecuador, he could identify as many as over 500 species of birds at a single site in places like Manu National Park, explorers in Eastern Peru, along the base of the Andes. So that’s phenomenal.

When you think about it, identifying over 500 species, and many of those species have multiple vocalizations, that’s extraordinary. And he learned that all pretty much on his own. And at that time of his death, he had contributed over 10,000 recordings to Macaulay.

And up until just a few years ago, that was still the most by any individual in the Macaulay Library. So up until just a handful of years– and he died in ’93– 10,000 audio recordings– extraordinary contribution.

[Glenn Seeholzer] So, yeah, let’s put that in context too for what it was like to record back then because we didn’t have– right now, a modern piece of recording equipment is about this big.

[Mark Robbins] Wow.

[Glenn Seeholzer] Right? And he was using this massive reel to reel maybe 20 pounds of lead and steel. And that’s not even including the eight D cells that you have to put in the back of it.

[Mark Robbins] Right.

[Glenn Seeholzer] And you also record on similar kind of technology. And so what was it like recording with this kind of technology?

[Mark Robbins] It was a pain in the ass. As you mentioned, it was so heavy. It was awkward, cumbersome. And things changed in the early 1970s, when Sony produced this– called a TCM 5000 cassette recorder.

It was much lighter weight. It took C batteries, had a counter on it. You didn’t have to exchange those magnetic reel to reel tapes. You could just stick in another cassette. And so that revolutionized recording in the field because it was truly a portable machine, unlike what you showed earlier, which was– it was limited where you could carry that, particularly if you were in difficult field conditions.

[Glenn Seeholzer] And what was it like– and so now we can– when we make a recording on our phones or with these digital recording devices, we have a really easy, fast pipeline for uploading the audio to Macaulay Library, through the eBird, like Manage Media tools. But in the 1980s, 1970s, what was the process like for archiving and recording, that is, sharing that recording with the world?

[Mark Robbins] Well, the first thing we would do is you would listen to each cut. And you would fill out a form from the Macaulay Library. And it would probably take you three to five minutes to fill out that paper form.

And then once you’ve done that for every cut on that cassette, you would send the cassette with a summary of what was on each cassette and those data forms. And then that would be all processed at the library. And you can imagine how time consuming that was for everybody on both ends of that.

[Glenn Seeholzer] Yeah. At some points, we had, I don’t know, up to 15 staff dedicated audio engineers working here, helping manage the recordings that were mailed physically on reel to reel cassettes here duplicated to create the recordings– the archive that we can see back here. And so it was a really different time but still kind of what connects us– what connects all these generations is essentially how much fun it is to record bird sounds, how beautiful they are, as Mike mentioned, and the kind of thrill of discovery. And I guess– I mean, in your words, Mark, what’s beautiful about sound recording to you?

[Mark Robbins] Well, every aspect of it. But you don’t have to go to an exotic place to appreciate the thrill of recording something as common as an Eastern wood pewee in Eastern North America during the summer. I get a thrill out of recording a nice recording of that and then uploading that on your eBird checklist, that you’re making a contribution.

It doesn’t have to be in some remote jungle, in some remote place of the world. You can make a valuable contribution to science. And as we all appreciate, the world is changing so fast. It’s important that we document everything, whether it’s birds, amphibians, mammals. And Macaulay Library is much more than birds.

[Glenn Seeholzer] Yeah. So what’s a good example of the ways bird sounds have changed through time?

[Mark Robbins] Well, there was a study published very recently about how the song of the white-throated sparrow– it’s a species found in Eastern North America. And it looks like its winter range distribution is moving North with climate change.

Some researchers took recordings from the Macaulay Library and showed that this common species– its voice had changed across the entire continent from a three-noted song to a two-noted song in just a few decades. So that’s just one example of what these recordings can do in a short amount of time.

[Glenn Seeholzer] Yeah. Thanks, Mark. And for those interested, you can look– there’s actually an all about birds article about that very study. And for people in Eastern North America or the Midwest, it’s likely you can go out and hear both those song types of white-throated sparrows as they begin the call this spring. They should be calling on their wintering grounds as they start moving farther North. It would be really cool to go out and document where those individuals are on their wintering grounds, for instance.

So, yeah, lots to do. Lots still to do. We now know what all the birds sound like. But we don’t know what they’re going to sound like in 50 years, 100 years. And so it’s really important that we’re documenting these things consistently to understand. This is an amazing experiment we’re all running as a community, just collecting these data through time.

Well, Mark, thanks so much for joining us. I’m going to pass it back to Alli. And we’re going to continue on with the rest of the celebration. All right. Bye, y’all.

[Alli Smith] Awesome. Thank you so much, Glenn and Mark. That was a really fascinating look at some of the history behind sound recording. So Glenn and Mark spoke a little bit about how important older recordings are for our understanding of how birdsong changes over time.

And this room that Glenn and I are sitting in right now is full of thousands and thousands of recordings from the last century. But they’re all on physical tapes, like this one here, rather than– yeah, they’re all on these physical tapes. And one of our goals here is to make these older recordings, all these tapes accessible online so that anyone in the world, any of you watching right now can access these and learn from them.

And we do that by digitizing these tapes. And the process of digitizing is pretty fiddly, kind of complicated. And it can be a many hour or even many day long process from start to finish in some cases. So to show it to you here, we put together a short video that shows that process that I will play for you now.



– We’re in the collections room in the Macaulay Library at the Cornell Lab in Ithaca, New York. The shelves in this room contain thousands of physical tapes in many formats of sound recordings of birds and other animals. Today, we’ll be digitizing this open reel tape that was recorded in Kenya in 1981 by ornithologist Jennifer Horne.

According to the data sheet associated with this tape, this is a recording of a black-collared barbet, a medium sized bird found in the forests of Southern Africa. We bring the tape into a digitization studio, which has the specialized equipment that we need for this task. The tape gets loaded onto the machine. And a strip of white leader tape is spliced onto the end of the magnetic tape.

The tape is currently on the reel backwards. So we need to rewind it before digitizing it. To do that, we thread the tape through the machine and onto an empty reel and rewind.

Next, we clean the machine. This is an older tape that’s beginning to degrade. And it shed a little bit while rewinding. This part of the machine is responsible for reading the tape. So it’s important to keep it clean to minimize interference.

Now we’re ready to digitize. We thread the tape back onto its original reel, set the speed of the tape, press a button to engage the rollers and maintain a constant tension, and play. As the tape rolls over the play heads, it’s turned into an electrical signal, which is then converted to a digital signal by an A to D converter and then sent to a nearby computer.


This tape is 24 minutes long. So we wait for the whole tape to finish playing before moving on to the next step. Once it’s finished, we can archive the recordings that were on the tape. A single tape may contain many recordings. So let’s edit and archive the one that we’re interested in.

We apply archival edits of trimming and normalizing and adding silence to clarify where segments of the same bird start and stop. We can then enter the important metadata that describes the recording. This data came from a form that the recordist filled out in the past. But data can also come from field notes, other spreadsheets, or even from voice announcements on the tape itself.

The final step is to upload it to the Macaulay Library. Now this recording is part of our digital archive and is available online to anybody in the world who wants to listen.



[Alli Smith] Awesome. So right now, if you were to go on to the Macaulay Library’s website and look at those 2 million recordings, about 8% of them, around 150,000 recordings total, came from these tapes behind me that went through that process that we just saw. And the rest of those recordings, the other 92%, are digital recordings. And most of those came from people like all of you who are watching right now who recorded either on their phone or with a microphone and submitted those recordings to us through their eBird checklists.

Because recording is so much more accessible today than analog recording was in the past, we’ve really seen a major increase in the number of people recording in the last several years, which is what’s led us to reaching this 2 million recordings in our archive, this milestone. And these two million recordings are having a really incredible impact both in research and in education. And, Glenn, as the curator of the Macaulay Library, part of your job is to keep up with the scientific research that uses the collection. Could you talk to us a little bit about what some of that research looks like?

[Glenn Seeholzer] Yeah. So there’s so much happening. It’s actually really hard to keep track because we send out recordings to researchers. They use it for the thing that they said they were going to use it for. And then they go off and use it for something completely different. And it’s really exciting to see all the different ways that recordings can be repurposed and the new questions that people come up with them– for them.

So recordings are used in a wide variety of fields– taxonomy, evolution, speciation research, the field of, bioacoustics and bioacoustic monitoring for conservation. And I think at the heart of bioacoustics is behavior. This is essentially an animal behavior.

And today, we actually have with us a avian behavioral expert, Dr. Karan Odom. She’s an assistant professor at the University of the Pacific in California. And she uses the ML archive in a really interesting and fascinating way.

And she’s really one of the leaders of an area of research concerning female birdsongs. And so she’ll be updating us on her progress documenting, understanding this really under-appreciated but extremely active vocal lives of female birds. So, Karan, thanks so much for joining us today. And, yeah, I’m looking forward to hearing about your work.

[Karan Odom] Thank you, Glenn. Thank you for having me. I’m excited to be here today to tell you about my research on female birdsong. But I am especially excited to be here to tell you about the exciting research that can be done with collections like Macaulay Library.

And so first off, why are female birdsongs interesting? Why do we want to study them? Well, historically, birdsong was thought to be primarily a male behavior.

So when people were originally recording or observing birdsongs or studying birdsongs, they were often recording or studying the songs of males. And birdsong, for quite a while, was thought to be primarily a male behavior. However, in recent decades, we have started to realize that female birdsong is a lot more common than we previously thought. And specifically, my colleagues and I have been able to show that female song is fairly widespread, that this is a behavior that occurs in not just a few species. But it occurs throughout the songbird family tree and a lot of really different and diverse species.

And then something else interesting that we were able to show, which I think really emphasizes why it’s important to study and understand female birdsong specifically, is that we think that females sang is the ancestor of all songbirds. We were able to use phylogenetic reconstruction to–

[Glenn Seeholzer] Were you going to share your screen? I think you were.

[Karan Odom] I was. Sorry. Thank you for pointing that out.

[Glenn Seeholzer] Yeah, you made some beautiful slides. I just want to make sure everyone can see them. Thanks.

[Karan Odom] OK. So here we go. Thanks for stopping me now before I got too far. OK, sure. So there you go. Can you see that?

[Glenn Seeholzer] Yep, that looks good.

[Karan Odom] OK, great. So as I was saying, we were able to show that female birdsong is not only widespread but that probably the ancestor of all songbirds females were singing in that ancestor too. And so what this means is that female song evolved really early on and that female songbirds have been singing for millions of years alongside male song. And their songs have been diversifying. And there’s a wide array of species with female song today. And so it’s a really very interesting behavior and, I would say, really relatively underexplored.

And so the other thing that I really love about female birdsongs– and this goes for birdsong in general. But female birdsong can be really diverse. And so I want to show you a few different examples of female bird songs.

So this ranges from everything like species, like this white-crowned sparrow, where males and females both look the same. But it turns out males and females actually sound the same too.


This is the song of the female.


And if you know the white-crowned sparrow, you can tell it sounds really similar to the male.


However, there are species, like this canyon wren, where both males and females sing. However, the female song is really quite different. The females kind of have their own song that’s different than the male song. And so I’ll play that for you here.


First off, it’s really buzzy.


And it’s also this rising song.


And comparatively, the male song is this really pure tone, descending song. So this female song is really different than the male song. And then we have species like the scrub jay. And actually, a lot of members of the scrub jay genus, females give this rattle call. And this is interesting because the male actually has nothing like a rattle cal. There’s nothing in his repertoire. Like that and we think that it’s a call that females specifically use for their own form of territory defense.


And so that’s the scrub jay calling.


And that clicking sound is the rattle.


And again, only the females do that. And then last but certainly not least, I want to play for you a few different songs by these neotropical wrens. I think it was– Mike mentioned earlier– somebody mentioned that wrens in general just have really, really beautiful songs. But then in some species, the males and the females actually combine their songs into these duets.

And in some species, they can be so highly coordinated that it can sound like a single bird species– sorry, a single individual or a single bird singing. And so first, I’ll play for you this rufous and white wren. This is sort of a simpler duet, where the male sings first. And then the female is going to overlay and sing her higher pitched song. So the male starts slower and then the female sings.


But then we have the buff-breasted wren, where the male is going to sing two lower notes. And then you’re going to hear this series of high to low notes. And the female sings the high part. The male sings the low part. But it’s in almost perfect unison. And it happens really, really fast.


And then lastly but certainly not least, I’ll play for you the happy wren, which similarly the male sings these lower parts. He finishes his song with two fast lower notes. And then the female chimes right in, almost seamlessly going from high to low notes such that it’s really difficult to even tell where the male song ends and where the female song starts.


And so what I was interested to do as a postdoc at the Cornell Lab of Ornithology is I was interested to look at, how complex are female songs? And how do they vary across a wide range of species? And are they as complex as male songs? And how do they compare to male songs?

And so to do this, I used Macaulay Library, and I’m in all of the wonderful songs available in that collection and, specifically, focusing on species where there were male and female songs in the collection. And so I ended up with a data set of 138 species covering 40 different songbird families. And it took me and a whole army of Cornell undergraduates or Cornell students in order to label all of these songs so that we could extract measurements in this Raven sound analysis software. And so in the end, we ended up with over 100,000 bird song notes that we labeled so that we could extract measurements from those songs.

And so here is the outcome of what that data looked like then when we put it in statistical software. So we have species, like I told you before, where the canyon wren male and female songs differ. And when we plot the measurements taken from all of those songs, we can see that these measurements differ as well and that they fall into a different acoustic space versus if you have a song like the superb fairywren, where the male and female song is really very similar, the male and female songs overlap statistically in this acoustic space.

And so using that kind of process, we can actually measure songs and song variation across a wide range of species and then plot them on phylogeny. And in the end, what we were able to conclude from this study is that male and female songs are actually really similarly complex. Male and female songs may not be exactly the same. But male and female songs are really diverse and complex in many songbird species.

And so, so far, I’ve told you a lot about what we already know about female bird songs. But this information really only comes from about a quarter of songbird species. And there are about 73% of songbird species that we don’t even really know what the female singing behavior or female vocal behavior is like. So there’s still a ton to learn.

And so to try to get at this my colleagues, and I, in collaboration with the Macaulay Library, have created this female birdsong project, a citizen science project, in order to encourage people like you, people who really love and enjoy recording bird songs to contribute to the discovery of female birdsong by contributing their recordings to these collections. So thank you, everyone, for listening.

[Alli Smith] Awesome. Thank you so much, Karan, for joining us. That’s fascinating.

[Karan Odom] Yes, thank you.

[Alli Smith] So we have 2 million sound recordings. And that alone is incredible. And we’ve shared with all of you tonight just some of the things that we’ve been able to do with these recordings so far.

But we want to keep doing more to help birds and to help people learn about them. And that means the next thing we want to do is to get to 3 million recordings next and then 4 million and beyond. And we can do that with your help even if you’ve never recorded a bird in your life before.

So here with me today is also– in addition to Glenn, we also have Jay McGowan, who is a project leader here in the Macaulay Library and an incredible sound recordist. So, Jay, could you tell us and the audience here just some advice on getting started with sound recording?

[Jay McGowan] Yeah, absolutely. So, yeah, it’s really not that hard to get into sound recording. We live in a really cool time right now, where pretty much everyone is walking around with a microphone and a recorder in their pocket in the form of a smartphone. You’re not going to make maybe like professional grade recordings with a smartphone. But with good technique, you can make some really decent and really valuable recordings that can be part of this archive, this initiative.

So the first thing you need is an app for making a recording, something that records uncompressed files– so not like MP3’s or M4As ideally but WAV files. We recommend just using Merlin, the built-in sound ID feature. Even if you don’t necessarily care about getting the suggestions for the birds you’re hearing, it makes really good recordings. So you can use it just as a recording app to record and save those, share those, and ultimately upload those to the Macaulay Library.

So then in terms of technique, just a couple of quick tips. First, get close to the bird. The closer you are to the bird, the better the recording is going to be, the louder the bird will be, and the less background noise there will be. Obviously, try to avoid disturbing the bird or scaring it off. But if you can start by approaching a little bit, that’ll definitely improve the quality of the recordings.

And then the second thing is to try to stay quiet. You’re going to be closer to your microphone than any bird is. So any noise you make will really get picked up by the microphone, whether you’re using a smartphone or some other kind of recording device.

So try not to wear swishy clothes. Try to stay still. Try not to talk during the recording. And then record for a minute or two. The better the situation is, the longer it might be worth making that recording.

So that’s the simple tips. If you want to get more into sound recording, kind of take them to the next level, there’s a number of specialized equipment that you can use. You can use a directional microphone, like this.

This is a shotgun microphone that’s going to pick up more of what it’s pointed at than the sounds coming in from the side. So that’ll really help kind focus your recordings and make them sound nicer. This one has an adapter that you can actually connect directly to your smartphone.

But you can also invest in a dedicated recorder, like one of the ones that Glenn was showing before. And actually, we have kind of good news on that front. We actually have a really preferred recorder right now that works really well. It’s this. It’s a Zoom F3. I’ll post a link to some gear recommendations in the chat here in a minute.

But this is kind of a top of the line recorder, honestly, right now. It’s a lot to– it makes really nice recordings. And it’s a lot cheaper than other recorders in the past were of similar quality. So really exciting there.

And then if you really want to take the next step and be a sound recording pro, then you can invest in a parabola. Now, this is a bit more cumbersome. It’s a bit more of a commitment to go out in the field with this.

But it’s really worth it if you’re able to because it really helps focus in. It amplifies the birds that it’s pointed at and not the background sound. And so you can really kind of lift those birds out of the background noise and get a really, nice, clean recording with that. So not for everyone but something to aspire to potentially if you’re interested in taking recording to the next level. So, yeah, those are just a couple ideas. And we really look forward to having your help getting to 3 million and beyond, like Alli said.

The last thing I’ll mention is we want to share today– we developed a sound recording course with the Bird Academy department here at the Cornell Lab a couple of years ago that goes through– it’s called How to Record Bird Sounds. And it really goes more in depth with all of those things I just mentioned very quickly in terms of learning about birdsong, finding a place in a bird to record, selecting equipment, and the field technique and post-processing afterwards. That’s really important too, obviously, to share your recordings, upload them to your eBird checklists. They’ll automatically become part of the Macaulay Library and help us all achieve this collective goal.

That sound recording course is on sale for half off, specifically for this event this week. So jump on that. They’ll a post a link in the chat here too. And otherwise, search for how to record bird sounds on Bird Academy. And, yeah, we look forward to having your help.

[Alli Smith] Awesome. Thank you so much, Jay. Yeah. So the Macaulay Library really is a resource built by birders, just like all of you watching today. And I and Jay And Glenn and everyone else here at the Cornell Lab want to give a huge thank you to all of you to more than 30,000 sound recordists from all around the world who have contributed to the Macaulay Library and to this resource that makes learning about birds more accessible to everybody. Thank you all so, so much for sharing your work and helping us better understand birds.

And before we go, I want to end with a couple of things. I have two different videos I want to share. And the first one is just a little bit of inspiration with a video that we put together of a couple sound recordists sharing some of their work with us. So I’m going to share that first video now. And then we’ll come back for one last goodbye.



– My favorite recordings was from 2021, when it was at the Amazon forest and a pair of redfin parrots leaning on a tree in front of us.


–like the most about this recordings are not just the vocal calls they perform but also the little notes and whistles they give in between. I also enjoy that the target species has the vocal attention. But you can also hear other species in the background– the little tinamou, the crested oropendola, and the Amazonian antpitta, giving a sense of the rich soundscape. The opening to that recording takes me right back to that amazing encounter.

– Hi, my name is Ramit Sinagl. And I love birding by ear. And sound recording allows me to delve deeper into that aspect of birdwatching and birds themselves and be able to understand their sounds and their behavior a bit better.

A few years ago, on my birthday, we went to this remote corner of South West, Tasmania. We watched these birds called the orange-bellied parrots, of which less than hundreds remain in the wild. And I was able to make a few sound recordings that, to this day, remain some of my favorites ever.


– So I really love recording for quite a few reasons. But the main reason is because when I’m recording, I feel like it’s so intimate. It’s just me and the bird at that moment in time.

And I think there’s no better feeling than to have that– your headphones on and you’re recording a song or a call. And it’s just this wonderful moment that you’re sharing with this bird.


– Hi, I’m Simone Dena. I’m from Brazil. And I love recording animal sounds because it’s a type of documentation that can really evoke emotions and memories of natural environments and different places. It enables us to connect sounds with the animal behaviors. It can spark communication about evolution, ecology, and every other topic. The recordings serves as a passage that can transport us through time and space.


– Hello, my name is Wil Hershberger. And I love recording birdsong. There’s nothing like getting a bird focused with your microphone and listening to all the intricacies of what the bird is doing. And then it’s really special to be able to take those recordings home and look at the sound spectrograms and see exactly what the bird is doing. That’s just magical.

One of my favorite recordings is that of a brown thrasher. It appeared to be a female. The male was singing nearby. It was late in the day on a spring evening. And as the light faded, she continued to call, worked her way down into the multiflora rose bush further, and tucked her head under her wing and went to sleep.


And then I thought to myself, now what do I do? I don’t want to disturb her and wake her up. So I had to back off super slow and carefully so as not to disturb her. Recording the sounds of birds is a life changing endeavor.


[Alli Smith] All right. A huge thank you again to all the recordists in the video, to everyone watching tonight, and to all the other Cornell Lab staff and guests that spoke on camera today. We’re going to turn our cameras off now. But I’m going to leave you all with one last video, this time of just some of our personal favorite bird sounds. And then the webinar will end after that. So have a great night, everybody. And thank you all for watching.

I’m sharing the wrong screen. My bad. My bad. One moment please. We’ll get there. Hold on. I promise have a video. All right, here we go.


End of transcript

Join us for a virtual celebration as we mark the milestone of 2 million sound recordings archived in the Cornell Lab’s Macaulay Library. We’ll pay homage to the contributions of the global sound recording community and explore the diverse applications of these recordings in research, conservation, and public engagement. Learn about the pivotal role of sound in understanding and preserving our natural world, and be inspired to contribute your own sound recordings to this invaluable archive.

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