Chirp chirp, y’all! Ever wondered what birds mean when they’re singing their little birdy hearts out? This week, Molly and cohost Bessie explore the kinds of sounds birds can make, and how those sounds are used. Birdsong researcher Kristin Brunk breaks down some sweet tweet science, and we learn how human noise has affected our feathery friends. Plus, a groovy new Mystery Sound!

Bird sounds in this episode came from Xeno-Canto:

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CHILD 1: You're listening to Brains On! Where we're serious about being curious.

CHILD 2: Brains On! is supported in part by a grant from the National Science Foundation.


SCOTTIE WARBLER: We're coming to you live backstage at The Chirp, the nation's only bird song competition. I'm your host Scottie Warbler. Everyone is looking fantastic. Sleek feathers, shiny beaks, flocks of talent all in one room. I'm here now with beloved judge, Wren Stefani. Wren, what are you excited to see from our contestants tonight?

WREN STEFANI: Well, last week Doja Cat Bird absolutely killed it with her pop version of "Tweet Child of Mine." She's going to have to really fly the extra mile to top that. And I think Alvin and the Cherpmunks will do well if they can stop squabbling and work together as a group. They've been fighting over the bowl of bugs in their dressing room all afternoon.

SCOTTIE WARBLER: Oh, well, we'll see if those birds of a feather can pull it together. Thanks, Wren. And now over to fan favorite Tweeter Aura. How are you feeling about competing tonight?

TWEETER AURA: Oh, my gosh Scottie, I was so nervous this morning. I thought I was going to totally barf worms. But I got the best pep talk from my coach, Kelly Larkson. She's been such an inspiration to me. She reminded me that I was born to sing.

SCOTTIE WARBLER: Amazing! Well, we're all excited to hear you knock your performance out of the nest tonight. And here are Meg and Jack Shrike of the White Shrikes. Great to see you both. I loved your version of "Rocking Robin." It was a totally rad remix.

MEG SHRIKE: Thanks so much, Scottie. We were inspired by classic squawk-and-roll groups like the Tweatles, the Moody Bluebirds, Cheep Trick. And, of course, The Birds.

JACK SHRIKE: We love giving the audience something they can really shake a tail feather to.

SCOTTIE WARBLER: Well, all my tail feathers are ready to rock. And now it's time for--



MOLLY BLOOM: You're listening to Brains On! from APM Studios. I'm Molly Bloom. And my co-host today is Bessie from Hudson, New York. Hi, Bessie.

BESSIE: Hi, Molly.

MOLLY BLOOM: Today, we're talking about songbirds and the sounds they make. And you had a question about that, right?

BESSIE: Yeah, I wanted to know how songbirds communicate with each other. Do they have a certain chirp for every word?

MOLLY BLOOM: This is a great question. And I can't wait to answer it. So let's get pumped up by starting with some bird facts.

BESSIE: Chirp, chirp, y'all. Bring on those facts.



--not all birds are songbirds.


--songbirds have special toes that help them perch on branches.


--they have cool muscles in their throats that give them really precise control of their tweets.


--and that's why they can produce such cool sounds.

MOLLY BLOOM: Whoo, those were great facts. You really know your stuff. So, Bessie, I'm wondering, do you have lots of birds singing where you live?

BESSIE: Yes, a bunch of different kinds.

MOLLY BLOOM: Can you recognize the different kinds by the songs?

BESSIE: Yeah, a couple of them.

MOLLY BLOOM: So what is your favorite one that you can recognize?

BESSIE: The morning dove. I actually know how to do that.

MOLLY BLOOM: I would love to hear that.

BESSIE: Whoo-hoo, whoo, hoo, hoo.

MOLLY BLOOM: Oh, yeah, I've heard that one before. I love that. That was really good. My favorite one to do is the chickadee.

Chickadee dee, dee, dee, dee. That one's fun because you just say chickadee and then say dee a lot. Do you try it?

BESSIE: [CHUCKLES] Yeah. Chickadee dee, dee, dee, dee.

MOLLY BLOOM: Nice, very good. So if you were a bird, what do you think your song would sound like?

BESSIE: I don't know. [CHUCKLES]

MOLLY BLOOM: Well, OK, here's an idea. So since the chickadee, its call is its name, is there a call based on your name? Like the Bessie call? So mine is Molly.

My name is Molly. I think I have a loud laugh sometimes. So I think it would be Moll-- he, he, he, he, he. Moll-- he, he, he, he.


MOLLY BLOOM: How was that?


That was silly. OK, now your turn.

BESSIE: I think I'd just say my name.

MOLLY BLOOM: OK, let me hear.

BESSIE: Like, Bessie, Bessie, Bessie, Bessie, Bessie.


MOLLY BLOOM: I love it. That's great. Well, to help answer your questions, we have Kristen Brunk here. She's a scientist who studies birds and their songs.

BESSIE: Hi, Kristen.

KRISTEN BRUNK: Hi, Bessie. Hi, Molly.

BESSIE: Do songbirds have a different chirp for every word?

KRISTEN BRUNK: Songbirds, when they interact it's not exactly the same way that humans have a word for everything that we want to say. There's a lot of information that's contained in bird songs, but they're not necessarily using words like people do. Birds make all kinds of sounds when they're communicating.

And there's two main types that we split them into. The longer, more complex ones we tend to call songs. And the shorter, simpler really quick rapid fire ones, we tend to call calls.

MOLLY BLOOM: Oh, OK, so the noises that this water thrush is making would be a call.


BESSIE: So what's something that a bird can say with a call?

KRISTEN BRUNK: Calls are used for such a wide variety of things. It might be mates communicating with one another about where they are while they're foraging. It might be an alarm call, where a bird is trying to indicate that there's a predator nearby or some other sort of danger.

MOLLY BLOOM: OK, let's hear what a gray catbird sounds like when it sees a threat.


KRISTEN BRUNK: So calls are used for a much wider variety of things than songs are. Calls are year-round, any time because birds are always communicating with one another, with other members of their species, or potentially with members of other species.

MOLLY BLOOM: So bird calls are a little like text messages. Very cool. What about their songs?

KRISTEN BRUNK: Songs tend to be-- at least in the northern hemisphere, they tend to be really focused in the breeding season. And so in the northern hemisphere, that's in the summer, some of the birds down in the southern hemisphere will sing year-round. They'll sing their songs year round because they're defending those territories all throughout the year. So it really just depends what they're trying to say and who they're trying to say it to.

MOLLY BLOOM: This yellow warbler sure has a lot to say. Let's hear it.


BESSIE: So if bird calls are like texts, then bird songs are like male birds advertising all their best qualities to the lady birds, right?

KRISTEN BRUNK: Absolutely. Yeah, that's exactly what they're doing. They're indicating their quality to all of the females in the area.

But there are times off-season that birds are singing as well. And there's a couple of ideas about why they could be singing in the non-breeding season. One of them is just that they're potentially practicing and trying to get better for the next year because practice makes perfect as we all know.

And another rising idea about why this is happening is that some birds actually in the non-breeding season when they're singing. And a lot of these are social birds. Things like European starlings.

MOLLY BLOOM: Ooh, let's hear a starling.


KRISTEN BRUNK: They're actually singing because it's fun. They're getting a rush of chemicals to their brains when they're singing that is signaling them to continue singing. And so in the same way that when you sing in the shower, it's fun for you, these birds are having a good time out there singing. Not really directed at anyone, they're just singing off on their own. Which is pretty cool and, I think, pretty relatable.

MOLLY BLOOM: Like this collared towhee keeping its tune fresh.


BESSIE: Aw, singing makes me happy, too. But how do songbirds know what songs to sing? Do their parents teach them?

KRISTEN BRUNK: That's such a great question. And it really depends on the birds. So some birds are hatched and they innately-- we call it innate, which means it's preprogrammed into them. Some species innately know their songs when they hatch.

And others, most of them in this really large group of birds that we call the passerine. So they're the songbirds or the perching birds. And this is over half of the bird species that exist. These guys actually have to learn their song through this whole four-step process throughout their lives.

BESSIE: They're learning what their voices sound like?

KRISTEN BRUNK: So even within an egg and soon after hatching, birds are listening to their parents singing or potentially making alarm calls. And just like when a human baby is born and they're listening to their parents speaking, this is when the nestling is learning the song template and the cadence of the song and what it sounds like. And then pretty soon after that, once young birds start to get a little bit bigger, once they start to leave the nest, they'll start singing their own songs.

And as you expect, they have almost no practice. So they don't sound that good. They're really just making noise, kind of like a human baby babbling. They're starting to make noises and learn what their own voice sounds like while still continuing to listen to their parents.

MOLLY BLOOM: Here's what a baby blue jay sounds like babbling.


Wow, that baby bird was trying out a lot of different sounds. That's amazing.

BESSIE: Thanks, Kristen.

KRISTEN BRUNK: Thanks, Bessie. Thanks, Molly. It was great chatting with you guys.

MOLLY BLOOM: Bye, Kristin.

BESSIE: Bye, Kristin.

MOLLY BLOOM: Speaking of sweet sounds, Bessie, how about we tweet ourselves to the--


Bessie, are you ready to hear this mystery sound?




Do you want to hear it again?



MOLLY BLOOM: OK, what do you think?

BESSIE: Maybe-- part of it kind of sounds like a zipper.

MOLLY BLOOM: Ooh, I can hear that, yeah. Yeah, sounds like something's going up and down. What else do you hear happening?

BESSIE: Something like loud.


BESSIE: Kind of like banging.

MOLLY BLOOM: So we think maybe zipper is a possibility. Any other possibilities you think?

BESSIE: Maybe a drill?

MOLLY BLOOM: Mmm, interesting. Well, we're going to hear it again. Get another chance to guess and hear the answer after the credits.

BESSIE: So stick around.


MOLLY BLOOM: Hey, friends. We're working on an episode about birthdays. And we want to hear from you. We all know the birthday song.

It's great, it's everywhere, but imagine it was your job to come up with a new song to sing to everyone on their birthdays. What would it be? Bessie, what would your new birthday song be?

BESSIE: I don't know. I like the original one.

MOLLY BLOOM: I do, too. I am a fan of that one. Well, maybe it could just be your birdcall. You just go Bessie, Bessie, Bessie, Bessie, Bessie when it's someone's--

BESSIE: Oh, yeah, Bessie, Bessie, Bessie, Bessie, Bessie.

MOLLY BLOOM: [LAUGHS] People will look at you like, huh? And be like, yeah, blow out your candles now. It's the Bessie song. [CHUCKLES] How do you feel when people are singing happy birthday to you?

BESSIE: Um, I like it.

MOLLY BLOOM: Yeah. Do you look at the candles? Do you look at the people? What do you do with your eyes when people are singing to you? Because I always feel like I don't know where to look.

BESSIE: Yeah, I just look everywhere.


BESSIE: Mostly at the candles, though.

MOLLY BLOOM: Yeah, yeah, me too. Have you ever changed the lyrics to the birthday song?

BESSIE: We do like, are you one? Are you two? Are you three?


BESSIE: Then they say stop one and three.

MOLLY BLOOM: Oh, I like that. That's awesome. Do you do it at the end of the song?


MOLLY BLOOM: Cool, I like that little twist. Well, listeners, we want to hear your new birthday songs. Record yourself and send them to us at While you're there, you can also send us mystery sounds, drawings, high fives, and questions.

BESSIE: Like this one.

KATE: Hi, my name is Kate, and I'm from Texas. And my question is, why do some people sing better than others?

MOLLY BLOOM: You can find an answer to that question on our Moment of Um podcast. It's a daily dose of facts and curiosity you can find wherever you listen to Brains On! Again, that's

BESSIE: And keep listening.

You are listening to Brains On! from APM Studios. I'm Bessie.

MOLLY BLOOM: And I'm Molly. So it turns out you can't quite translate birdsong like you could another human language. Specific chirps aren't like specific words. They're more of a general feeling or vibe.

BESSIE: But even so, can different species of birds understand each other's chirps? Can they get the basic idea of what another bird is communicating?

MOLLY BLOOM: Well, yes and no. Sometimes when different bird species live in the same habitat, they learn to recognize specific kinds of sounds. So let me give you a human example to help me explain. So let's say you're in a new place and you don't speak the same language as the people around you, but you hear this. [LAUGHS] What would that tell you?

BESSIE: That someone's happy.


BESSIE: That someone's happy.

MOLLY BLOOM: Totally. And what if you hear this? [SCREAMS] What would that tell you?

BESSIE: That they're hurt or scared.

MOLLY BLOOM: Mm-hmm, exactly. So birds can understand each other in that kind of basic way. For example, they remember the alarm calls of other bird species. So if a robin heard this from a blue jay--


--the robin might know that the blue jay is sending out an alarm call. Maybe the jay saw a hungry cat prowling around. Or maybe it saw a snake. The robin wouldn't know for sure what scared the jay, but it would know to be careful.

BESSIE: Are there other kinds of calls they might be able to recognize?

MOLLY BLOOM: Yeah, there are things like, hey, that's my branch, go away! Or, ooh, some tasty bugs are over here. Since birds don't have a language like we do, they aren't exactly translating one another, but they can remember what happens when they hear a particular sound.

BESSIE: So birds can understand some bird calls from other species if it's useful to them?

MOLLY BLOOM: Yes. Like how I know when Mark goes [GROANS], it means someone ate the last of his queso. And that someone was me.

BESSIE: Does that come up very often?

MOLLY BLOOM: More than you'd think.


MOLLY BLOOM: Oh, got to go. Ha, ha!


So birds can make sounds to let other birds know danger is nearby, to attract mates, or just they can make beautiful songs that make them feel good.

BESSIE: But there are also some birds who are incredible mimics. They can sound like other things.

MOLLY BLOOM: Scientists have found that nearly 300 bird species imitate sounds they hear. Some are songbirds, but other birds do it, too. Mockingbirds can mimic all different kinds of sounds, like a lawnmower or a chainsaw.

And there's an Australian species called the superb lyrebird that might be the champion of copycats. I mean, copybirds. These cheeky chippers can imitate more than 20 different bird species in a single song.

BESSIE: Sometimes mimic birds use their powers in super sneaky ways.

MOLLY BLOOM: For example, there's a songbird called the fork-tailed drongo that lives in sub-Saharan Africa. And it's really good at imitating other sounds.

BESSIE: It uses its trickster abilities to score a quick meal.

MOLLY BLOOM: These drongos will listen to other songbirds and learn their alarm chirps. Then they'll wait until they see another bird about to pounce on a tasty bite, like bugs, worms, or lizards. That's when the drongo will sing a false alarm.

BESSIE: When the other bird hears the alarm, they'll think there's danger, so they fly away, leaving their snacks behind for the drongo to scoop up.

MOLLY BLOOM: Mimics pick up all sorts of sounds, including ones made by humans. But that's not the only way we've affected the way songbirds communicate.

BESSIE: Bird songs are actually changing. And humans are part of the reason why.

MOLLY BLOOM: Humans are noisy. We use machines with loud engines, we do construction work with loud tools, we have loud concerts.

BESSIE: And over time, cities have gotten noisier and noisier.

MOLLY BLOOM: Scientists have found that this noisiness has caused some songbirds to change the way they talk to each other.

BESSIE: In one study, researchers listened to recordings of white crown sparrows in San Francisco.

MOLLY BLOOM: These were first made starting in 1969. The researchers recorded sparrows living right in the middle of the city.

BESSIE: Then in 2005, they recorded the same type of sparrows living in the same parts of the city.

MOLLY BLOOM: And they discovered something amazing. In 1969, the sparrows sang at a lower pitch.


BESSIE: But in 2005, the birds were singing the same song, but at a higher pitch.


Low pitch.


MOLLY BLOOM: High pitch.


It might sound like a small change, but the songs are definitely different.

BESSIE: Scientists think that this is because of us. The city got much bigger in the 36 years since the first recordings.

MOLLY BLOOM: More buildings were built, more people moved in, more cars and buses on the road.

BESSIE: The birds had to change their song to be heard above all the ruckus.

MOLLY BLOOM: The scientists also discovered that the sparrows were not only singing higher, they were also singing louder.

BESSIE: Just like you might have to shout to a friend to be heard over a busy street, the sparrows have to shout, too.

MOLLY BLOOM: Many city noises, like traffic, are lower pitched. So by singing at a higher pitch, it's easier for the sparrows to cut through the noise.

BESSIE: Some songbirds have even changed their tweets to work around our schedules.

MOLLY BLOOM: The researchers noticed that some sparrows would avoid singing during rush hour because the cars were too loud. They compared their findings to white-crowned sparrows who lived out in the country. And they found that since 1969, these birds barely had any changes to the volume or pitch of their songs.

BESSIE: So the quiet country life is really good for the songbirds.

MOLLY BLOOM: Yeah, I bet it's exhausting to shout all the time.

BESSIE: I feel bad for them. Maybe we could get them some little bird-sized microphones.

MOLLY BLOOM: Then they might start a bird podcast. I would love to hear that.

BESSIE: Me, too. So there's one more really interesting thing about this. Researchers found something cool in 2020.

MOLLY BLOOM: When most places shut down at the start of the COVID pandemic, scientists had a rare chance to see how songbirds behaved when cities suddenly got quieter. They collected information on the same white crown sparrows in San Francisco that were part of the earlier study.

BESSIE: And they found that without all the traffic on the roads or people gathering in the city, the sparrows didn't have to shout anymore.

MOLLY BLOOM: The sparrows in the city began singing softer and at a lower pitch. Some of them even sounded incredibly similar to the country songbirds who never had to deal with city noise.



BESSIE: While songbirds don't have a tweet for every word, they do use sound to communicate.

MOLLY BLOOM: Bird calls are short sounds that could mean a bird sees a predator or has found a tasty snack.

BESSIE: Songbirds sing longer songs when they're trying to attract a mate or sometimes just for fun.

MOLLY BLOOM: And just like human babies try to copy their parents, chicks usually learn most of their singing skills by imitating their parents.

BESSIE: Songbirds can't understand everything the birds of other species say, but they can sometimes recognize alerts for food or danger.

MOLLY BLOOM: And we humans are changing how birds sing, too. They're learning to imitate our phones or machines. And some birds are singing louder and higher to be heard over all the noise we make. That's it for this episode of Brains On!

BESSIE: This episode was produced by Molly Bloom, Anna Goldfield, Molly Quinlan, Rosie duPont, [INAUDIBLE] Anna Weggel, Nico Gonzalez-Whistler, Ruby Guthrie, and Marc Sanchez.

MOLLY BLOOM: Our editors are Sanden Totten and Shahla Farzan. This episode was sound designed by Rachel Breeze. Beth Perlman is our executive producer. The executives in charge of APM Studios are Chandra Kavati, Alex [? Shafford, ?] and Joanne Griffith. We had engineering help from Roberto Chacon and Michael Osborne.

BESSIE: Brains On! is a nonprofit public radio program.

MOLLY BLOOM: There are lots of ways to support the show. Head to

BESSIE: While you're there, you can send in your mystery sounds, questions, and drawings.

MOLLY BLOOM: You can also subscribe to our Smarty Pass.

BESSIE: Super fun, ad-free episodes and bonus stuff just for you.

MOLLY BLOOM: OK, Bessie, are you ready to listen to the mystery sound again?


MOLLY BLOOM: OK, here it is.


BESSIE: Yeah, I still think that's a drill.

MOLLY BLOOM: It's a drill? Yeah, it does kind of sound like construction stuff. All right, you ready for the answer?


MOLLY BLOOM: All right, here it is.

DIA: Hi, my name is Dia.

[? ALIYAH: ?] My name is [? Aliyah. ?]

DIA: And we're from Millburn, New Jersey. That was the sound of us opening and closing our blinds.


MOLLY BLOOM: Yeah, that's a tricky one.


MOLLY BLOOM: So I guess the zippy noise was the sound of the string being pulled up and the blind going up?


MOLLY BLOOM: And then the big noise was it coming down again, I think.

BESSIE: Yeah. Yeah, probably.

MOLLY BLOOM: Probably. Do you have blinds at your house?

BESSIE: Yeah, but they're not that noisy.

MOLLY BLOOM: [CHUCKLES] You have quieter blinds, yeah.


MOLLY BLOOM: I get it.


Now it's time for the Brain Honor Roll. These are the incredible kids who keep this show going with their questions, ideas, mystery sounds, drawings, and high-fives.



SINGER: Brains on!

MOLLY BLOOM: We'll be back next week with more answers to your questions.

BESSIE: Thanks for listening.

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