How The Humpback Says Hello
A humpback whale makes two kinds of noises. The first are songs, long, elaborate, patterned and rhythmic vocalizations made by mature males, with some connection to the mating ritual. Within any given pod, every male sings the same song, but the songs themselves are different in pods around the world.
The second kind are calls, short sounds made by every whale, that seem much more consistent across populations and over time. Of around 50 documented kinds of calls, scientists have settled on the meaning of one for sure: the sound the whales make when feeding on one specific kind of fish.
In the decades since scientists first began to investigate the calls and songs of humpback whales, the exact function of these noises has been a tough mystery to crack. Humpbacks’ watery habitat makes researching them difficult and expensive, and the whales themselves live on slow time scales that make leaps in understanding a process that can take decades.
Now, the new documentary Fathom tells the story of two researchers working to further understand what humpback whales are saying, and why they say it. Cornell University researcher Michelle Fournet investigated a call—the ‘whup’ call—that seems to be a greeting, and found when she played the sound underwater, the whales responded back to her. And University of St. Andrews scientist Ellen Garland scoured recordings of South Pacific humpbacks to find out how pods will suddenly adopt new songs despite little contact with other populations.
Ira talks to Garland and Fournet about their work, the complexity of whale communication, and how understanding it better could help save them from human threats.
Michelle Fournet is a biologist And postdoctoral fellow in the K. Lisa Yang Center for Conservation Bioacoustics of the Cornell Lab of Ornithology at Cornell University in Ithaca, New York.
Ellen C. Garland is a biologist And Royal Society University Research Fellow at the University of St. Andrews in Fife, United Kingdom.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. Let’s say you’re a whale, swimming around, and you want to say hello. Well, if you’re a humpback, your howdy might sound a bit like “whoop”.
MICHELLE FORNET: I think the book is a kind of hello to them. Possibly, hello, I am. If each whale has their own whoop, could they use it to identify each other?
IRA FLATOW: That’s bioacoustics researcher Michelle Fornet talking about her groundbreaking work to identify the function of a small piece of the known vocabulary of humpback whales, a call that may be how they say hello. But what if you, not a whale, find whale music more your style?
ELLEN GARLAND: They have rhythm. Timed breathing. Rhyming and repetition.
Then maybe you would be interested in the work of Ellen Garland, who has been scouring the complex songs of humpback whales for evidence that whale songs may spread, across hundreds of miles of ocean, and be adopted by other whales. Their research is featured in the new documentary “Fathom”, which aired at the Tribeca Film Festival.
It’s now available on Apple TV Plus. And both of those scientists are here with me today. Ellen Garland is a Royal Society University research fellow, investigating the cultural transmission of humpback whales at the University of St. Andrews in the UK. Michelle Fornet is a postdoctoral researcher in bioacoustics and behavioral ecology. That’s at the Cornell Lab of Ornithology K. Lisa Yang Center for Conservation Bioacoustics. Welcome to Science Friday.
MICHELLE FORNET: Thank you so much for having us.
ELLEN GARLAND: Hello.
IRA FLATOW: Nice to have you. Ellen, let’s start with digging into your work first. Tell us about humpback whale songs, and the patterns and the themes there.
ELLEN GARLAND: Absolutely. So it’s only the males that will sing, and song functions in something to do with sexual selection. So either the males are singing to try and attract a mate, or they’re singing to other males saying, I’m big, I’m strong. Or it could be both. We’re just really not that sure at the moment.
But what we do know is that all males within the population will sing the same song. So this song is quite complex. It’s got many hierarchical levels in it, but they will all sing the same arrangement of the song each year. And it’ll change, and they’ll all make the same changes to their song. And this song progresses and evolves from year to year within a population.
And what we’ve been finding is that these songs are then passed between populations. The song on the east coast of Australia will then be passed to the next population over, which is New Caledonia the next year. And it will take over that whole song display. This whole new song will appear, and all the males will switch to these completely different songs. And that happens over and over again across that ocean basin. And this takes one to two years for a song– what we call revolution– to spread across.
The changes are revolutionary. It has happened with multiple different song types being passed from one population to the next, over and over again. Let’s listen to an example of the changes you observe. Here’s a clip from a song first observed in 2002, and then you watched it move eastward.
And here’s a sample from a song first observed in the same place in 2003, and then you watch that move to whales east of there.
IRA FLATOW: So these two songs are really very different. I mean, how easy is it for you to tell how different they are?
ELLEN GARLAND: So the differences are really striking. With humpback song, it’s a nested hierarchy. So single sounds I would call units. And we name these how they sound. So moans, groans, whoops, purrs. Croaks, I think you might have just heard.
And what you heard just there was a couple of sounds. So there’s a few sounds that will get organized into what we call a phrase. And so you heard a snippet of a phrase. And then these phrases repeated over and over again to make a theme. And then there’s a few different themes which are sung in a stereotyped order to make a song.
So it’s these multiple levels within this complex hierarchy. And so when a completely new song type comes in, it has a completely different arrangement of things, of sound types, within this.
And the differences are absolutely striking. And even if you’re not a researcher, you can hear how we have these different sound types present that different arrangements are present. So it’s a really striking change when these song revolutions come through the region
IRA FLATOW: And why are they adopting the new song? Is it something they hear through the water, and then they say, hey, let’s join in on that?
ELLEN GARLAND: Absolutely. So they’re hearing these new songs at different points within the year, but we’re not entirely sure exactly why they adopt these novel songs. Clearly, they like these novelty songs.
And we think it’s something to do with, of course sexual selection, so maybe the females are choosing males with novel songs. So it’s a pretty good idea to switch to something that’s slightly new, and we think that this may be driving the system. But we’re just not that sure at the moment.
IRA FLATOW: Would you say then that the whales are passing their culture from their pods, their families, to someone else’s culture?
ELLEN GARLAND: Absolutely. It’s these big cultural revolutions. So there are population wide cultural changes that are then passed from population to population. I like the analogy of, OK, so you’re singing your national anthem, right? You’re singing along, it’s all good, and then the next year you abandon your national anthem to what your name is singing. So insert whatever nation that is that you’d like to do there.
It makes no sense. And no other animal does these kind of large, population level changes at such a fast and rapid pace. Because it only takes one to two years to spread across most of an ocean basin. The only other animal that does that is humans. So we draw analogies with a lot of pop culture, how pop songs will spread across America, or if you know, you’re into the Beatles.
IRA FLATOW: Great analogy. Michelle, let’s move on to what you do. Because you’re not looking at the song spreading, but you’d like to eventually be able to talk to the whales, to communicate with them. So you’re learning how they speak to one another.
MICHELLE FORNET: Exactly. I’m learning how they speak to one another, and the best method for doing that is by talking to them ourselves. Being able to acoustically engage with a humpback whale is fundamental for understanding what the function of these calls are, what they mean, and how they’re used.
Through our speaker, we will project the sound of a humpback whale whoop call, which we believe is a contact call, and we will listen to see whether or not the whales are calling back to us. And we believe that if they call back to us, that that is evidence that this call is used to maintain communication, potentially maintain relationships, but certainly to make contact with other whales.
Let me play an example of that whoop call for our audience.
[WHALE WHOOP CALL]
IRA FLATOW: So what’s the big whoop about the whoop call?
MICHELLE FORNET: This call is possibly one of the foundational units of sound for all humpback whale communication. So Ellen explained to us that song is produced by male whales. Whoop calls are produced by everyone. Male whales, female whales, juvenile whales. All whales produce this sound.
And unlike song, which sort of shifts rapidly, and changes, and is unique to populations, and is very sort of complex, this whale call is stable for generations. So we’ve actually documented, in Southeast Alaska, this humpback whale whoop call persisting from generation, to generation, to generation. 40 or 50 years. But we’ve also found that this whoop call has been documented in populations.
So humpback whales that don’t interact with each other. And in fact, they’ve been genetically and geographically isolated for anywhere from two to three million years. And yet, they produce the same call. So all of that is evidence that, in strong contrast to song which is culturally transmitted, that this call is probably innate. It is something that these animals are born with, and rely on for basic communication.
IRA FLATOW: Well, when you played that whoop call on your microphone underwater to them, did they recognize you as another whale, and try to communicate with you?
MICHELLE FORNET: It certainly appears so, yes. Yeah. I mean, the ink is still drying on the final results, but I can say with high level of confidence that, when we went to Alaska, provided we set everything up just right, when we played a wolf call to the whales, the whales called back to us. Which was extremely, extremely, exciting.
IRA FLATOW: Michelle, the whoop call is the second humpback call of something like 50 that researchers have identified the function of. Why has it taken so long to begin to decipher these sounds? [LAUGHS]
MICHELLE FORNET: That’s a great question. I will remind everyone, and myself at times, that these animals do spend 80% of their life living underwater. So most of the time, we can’t see them. We are using every resource at our fingertips to try and understand what they’re doing when we can’t see.
And so, whereas for the whoop call we were able to experimentally test what the function is, you have to have some hypotheses about that first. And because the repertoire is so extensive, and their communication system is so complex, we are literally shooting in the dark when we first start to guess as to what these calls might be for. And as recently as, I guess, 10 years ago, we didn’t even have a catalog of the sounds that humpback whales in Alaska made. We didn’t even know, when we dropped a hydrophone in the water, if what we were listening to was a humpback, or was it rocks rolling down the side of the beach?
And so, we really were starting from a large unknown, and have been building up ever since on trying to figure out what these call functions are. And unless the call function is something that is observable by our human scale, forming hypotheses about it can take many, many years. Because we have to look at the data, and try and imagine the world from the perspective of a whale, instead of imagining the world from the perspective of a human.
IRA FLATOW: Interesting. And Ellen, how many years of data did it take for you to observe the shifting of humpback songs?
ELLEN GARLAND: So, these are decadal processes. And it’s only because I have the most incredible collaborators, and they have been recording for years, and years, and years. And I’ve been allowed to work on these recordings in collaboration with them. But you need these long term, multiple location data sets to try and piece these broad scale dynamics together.
And that takes years. But there’s a number of groups around the world where these big data sets are starting to come to fruition. And it just takes so much time and effort. And then analysis to do this. The work that we do, the analytical work. It is absolutely painstaking to piece these transmission dynamics together.
And so it starts on the water. Getting the recordings, observing the animal. And then back in the lab, and analyzing the sounds, and getting the sequences, and doing the statistics. And then trying to step back, and understand why these things are happening.
IRA FLATOW: I’m Ira Flatow, and this is Science Friday from WNYC Studios. Between the both of you studying the calls and studying the songs, at what point do you say, hey, this is language?
MICHELLE FORNET: Well, I would argue, never. Humans use sounds to represent concrete ideas. A thing, an action, an emotion. Animals don’t. There’s a handful of very discrete examples in nature where animals use representational sound, but generally, when an animal makes a sound, it’s because it’s trying to elicit either information, or a change. It’s trying to make something happen.
If an animal feels threatened, a mammal might growl. Now, we interpret that as saying stay away from me, but the animal doesn’t make that translation. The animal is trying to push something away.
And so when we think about whales, whales aren’t using a sound to represent an idea. They don’t have a call that means fish, but they do have a call that herds fish. And so language is this idea of symbolic sound use, whereas animals seem to have a functional sound use. So I don’t know what the right word is for it, except to call it communication, but I don’t know that I would go so far as to call it language.
IRA FLATOW: Interesting. Good point. Last question I have, because we’re running out of time. Humpback whales, like other whales, are at risk from climate change and human activities. Can understanding their communication and culture help us protect them, and in what way?
MICHELLE FORNET: I certainly think so. And conservation is at the foundation of my entire research program. In order to demonstrate quantitatively that these calls are essential for the survival of the animal, we need to know what they mean. And until we can demonstrate that they’re important, they’re hard to conserve. Anthropogenic noise is a real threat to marine organisms, as humans continue to put noise into the ocean.
Humpback whales reduce their calling rates when it gets noisy. They can’t hear each other when it gets loud. They have to exert extra energy, or they might get stressed when it gets noisy. And if these whoop calls are as essential as I think they are, and we have a noisy ocean, we might be doing is changing how these humpback whales function.
We might be altering their social structure, and that might have implications for how will they forage, or how will they breed. And so ultimately, the more that we understand about the basic behavioral ecology of an animal, the better job we can do of adjusting our human behavior so that we can find balance. So that we can successfully ship goods where they need to go, but we can do so in such a way that has a minimal impact on these animals.
IRA FLATOW: Ellen?
ELLEN GARLAND: Basically, if you think– well, they can’t see very far, so it’s all going to be about the sound. How are you going to find a mate if you can’t hear them? How are you going to continue this population if they can’t hear each other to actually breed?
So it’s so important, the conservation aspect. And even the cultural aspect is starting to feed into conservation management. So managing different cultural units is now happening, even with citations. So culture is feeding into some of the conservation efforts.
IRA FLATOW: I’d like to Thank my guests. Ellen Garland is a Royal Society University research fellow at the University of St. Andrews in the UK. Michelle Fournet is a postdoctoral researcher at the K. Lisa Yang center for Conservation Bioacoustics at Cornell University. Thank you both for such fascinating conversation.
ELLEN GARLAND: Thank you so much.
MICHELLE FORNET: Yeah, absolute, absolute pleasure to be here. Thank you.
IRA FLATOW: You’re welcome. And just a reminder that their research is featured in the new documentary “Fathom”, which aired at the Tribeca Film Festival, and you can now see it on Apple TV Plus. And believe me, the film made me wish I had their jobs.
Christie Taylor was a producer for Science Friday. Her days involved diligent research, too many phone calls for an introvert, and asking scientists if they have any audio of that narwhal heartbeat.
Ira Flatow is the host and executive producer of Science Friday. His green thumb has revived many an office plant at death’s door.