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limited by state law. What's

0:36

going on in a whale's throat that allows it

0:39

to sing? It's

0:49

Tuesday, March 5th. Politics folks call

0:51

it Super Tuesday. But we say

0:54

it's Science Friday. I'm

1:00

Sci-fi producer Charles Bergquist. Coming up,

1:02

we'll talk about research into the

1:04

larynx of baleen whales, like humpback

1:07

and minke whales, and how researchers

1:09

MacGyver device using party balloons and

1:11

exercise bands to explore its frequencies.

1:15

But first, why snakes deserve

1:17

our recognition as evolutionary superstars?

1:20

Here's Ira Fladeau. Ever

1:22

since those reported events in the Garden of

1:25

Eden, snakes have been

1:27

given a bad rap. Love

1:29

them or hate them. Turns out that

1:31

snakes are some of the most evolutionarily

1:34

elite creatures on the planet. And it's

1:36

not just me who's saying this.

1:38

A new study in the journal

1:41

Science finds that snakes evolve faster

1:43

than other groups of lizards. Yeah,

1:45

and their ability to adapt to

1:48

hyperspecific diets and circumstances

1:50

make them winners among vertebrates.

1:53

So what do you think about snakes now?

1:55

Well, joining me to share the science of

1:57

serpents is its senior author Daniel Robach. evolutionary

2:01

biologist and curator at the

2:03

Museum of Zoology University of

2:05

Michigan based in Ann Arbor.

2:07

Welcome to Science Friday. Thanks

2:10

so much for having me, Ira. I

2:12

want to get right into this. Why

2:14

are snakes such an evolutionary powerhouse? You

2:16

know that's a really good question. Why are

2:18

snakes such a powerhouse? I

2:20

think that you know at first it's not

2:23

immediately obvious to maybe a lot of

2:25

folks just how different snakes are within

2:27

reptiles but you know you look at

2:29

a variety of traits and you can

2:32

see this really profound shift between other

2:34

groups of lizards and snakes and

2:36

that's something that you know one of the things that

2:38

we document in our study that really carries through to

2:40

numerous aspects of their ways of life and their structure.

2:43

So obviously yes this raises this big question

2:45

of why and in some

2:47

ways we set out to answer the

2:49

question about this evolutionary shifts and sort

2:51

of what drives these kinds of evolutionary

2:54

differences in what different groups of

2:56

lizards do and part

2:59

of our answer that we find is

3:01

that snakes are simply doing things faster

3:03

their sort of evolutionary engine is running

3:05

hotter. What do you mean by

3:07

that? Give me an example. How do we know

3:09

that? That's a great question. So we know this

3:11

because one of the things

3:14

that we are able to do in our study

3:16

for example and within sort of

3:18

modern evolutionary biology more generally is take

3:21

some of these types of data that

3:23

are either we can get from from

3:25

genomes for example and from ecological data

3:27

like what things eat and we can

3:29

we can we can use statistical

3:31

methods to figure out how fast things

3:34

are evolving with respect to those kinds

3:36

of features like the shape of their

3:38

skull or the things that

3:40

they eat. So we can tell you

3:42

quantitatively that snakes for example are are

3:44

evolving new kinds of you know a

3:47

given given lineage of snake is evolving

3:50

essentially faster is exploring this

3:52

diet landscape of potential dietary

3:54

items more rapidly than the

3:56

average lizard for example. statistics

4:01

of it get a little technical, but

4:03

that's sort of the basic idea. Do

4:05

you say there are legless lizards that

4:07

may look a lot like snakes to

4:09

the untrained eye, but they're totally different?

4:12

That is correct. So there are a

4:14

number of sort of fine anatomical differences

4:16

that separate snakes out of a group

4:18

within the lizards. But there

4:20

are many groups of lizards that superficially are

4:22

snake-like. And so let's say, you know, I

4:24

could pick many examples of lizards that have

4:26

evolutionarily lost their legs, where I could hand

4:29

them to someone and say, like, is this

4:31

a snake or a lizard? And

4:33

people would be like, you know, it's a snake,

4:35

but actually it's a lizard and it's distinct from

4:37

snakes. Now, one of the

4:39

interesting things that we find in our

4:41

study is that when these other groups

4:44

of lizards evolve on this snake-like trajectory,

4:46

so they essentially discard their limbs, you

4:48

might say, well, there's something about being

4:50

a long, legless thing that sort of

4:52

predisposes you to maybe evolving faster or

4:54

specializing in the kinds of dietary things

4:56

that snakes do. And that's really

4:59

not what we see at all. For the most part,

5:01

the lizard groups that lose their legs, other

5:03

than snakes, have essentially stayed lizard-like.

5:06

And so it's a really remarkable

5:09

that the things that have gone

5:11

down this snake trajectory haven't done

5:13

what snakes have done, which raises other questions about

5:15

why. So you know, the

5:17

other ones are essentially still specializing on the

5:19

kind of foods that typical lizards would specialize

5:21

on, or they're not doing the same. They're

5:24

not using it as diverse of habitats. You

5:26

know, they're living a burrowing-type lifestyle, for example,

5:28

more often than not. So where

5:31

do snakes have, so to speak, a

5:33

leg up on lizards? In

5:35

what sense do snakes have a leg up on

5:37

lizards? Well, you know, what do we mean by

5:39

a leg up? So In one

5:41

sense, snakes have been tremendously successful. Of

5:43

Course, you know, lizards have been hanging

5:45

around for a long time as well.

5:48

Where Snakes have really shined, though, is

5:50

in terms of their ability to become

5:52

ecologically diverse, especially over the past 65

5:54

million years or so. There are a

5:56

lot of species of lizards, of course,

5:58

but I think snakes have... Have

6:00

managed to exploit a broader range

6:02

of habitats on the surface of

6:04

the earth and a broader range

6:06

of of of ecological ways of

6:08

life and dietary diversity. odd diverse

6:10

dietary strategies and so on. And

6:13

so I think fit in a one of the

6:15

thing that has set snakes up for in the

6:17

last sixty five million years as if sort of

6:19

an ability to take advantage of certain types of

6:21

opportunities that have happened in earth's history and one

6:23

of the things that we seem at as we

6:26

see a signal of after a for example probably

6:28

in the wake of the mass extinction that that

6:30

wiped out. Nine Avian Dinosaurs is

6:32

I sort of a a flourishing of sneak

6:34

diversity. The sort of kicked off and a

6:36

ten million years or so after that. that's

6:39

a pretty strong signal that that that shows

6:41

up in the snake record, and I do

6:43

think that it might have something to do

6:46

with that sort of underlying evolutionary speed. Aware

6:48

that evolutionary potential that Snake South, especially for,

6:50

has let them take advantage of new environmental

6:52

or ecological opportunities or when think about them

6:55

as are empty ecological niches. Give

6:57

give us a couple of of as

6:59

examples of snakes that develop specific nice

7:01

is in the diet's there are I

7:03

mean the catalog is is vast here

7:05

I will just a few of you

7:07

know give you a few of my

7:09

favorite examples that I think that one

7:12

of the things about snakes that really

7:14

separates them from lizards and something that

7:16

we show I think well in our

7:18

study is that snakes are much more

7:20

die utterly specialized than the average blizzard.

7:22

And. So. One. Of the

7:25

things that you see with his

7:27

snakes are these incredibly interesting dietary

7:29

strategies. For example, there are species

7:31

of snakes that specialize on feeding

7:33

on. Essentially. the soft

7:35

bodied mollusks like ah snails and slugs the

7:38

live in trees in their defended by these

7:40

heavy mucus secretions and he snakes him a

7:42

number of specialized adaptations to feed on these

7:44

things and that for the most part will

7:47

be the primary diet of those species or

7:49

the our species of snakes that are sea

7:51

snakes that have these in a long paddles

7:54

shape tail and they can dive down into

7:56

coral reefs and they are specialists on things

7:58

like fishing so they just probe through

8:00

crevices in coral reefs and look for fish

8:02

eggs and essentially scrape them off that coral

8:05

structure down there. There are

8:07

species of snakes that are, there are many

8:09

species of snakes that are specialized predators of

8:11

other snakes. So they are specialist hunters of

8:13

other species of snakes. So the list sort

8:16

of goes on and on. There are species

8:18

of snakes that specialize only on feeding on

8:21

larval termites. There are some

8:23

groups, some species that tend to feed

8:25

quite a bit on tree frog eggs

8:27

and there's some

8:29

interesting issues there with tree frog eggs essentially

8:31

evolving the ability to sense when a snake

8:34

is eating them and starting, and they will

8:36

hatch when they sense a snake starting to

8:38

eat their little clutch of eggs. It's kind

8:40

of remarkable behavior that happens in tropical rainforest

8:42

frogs. She just blew my

8:45

mind on that one. Wow.

8:48

How were you able to investigate

8:50

these interesting dietary habits of

8:52

snakes? I mean, did you just hang

8:55

around and watch them? That

8:57

is a good question. So how do we

8:59

get all this dietary information on snakes and

9:02

lizards? So it turns out

9:04

that for the vast majority of species

9:06

of snakes and lizards, there are virtually

9:08

no or very few observations of these

9:11

animals doing their thing feeding in nature.

9:13

They're very cryptic. They're very camouflaged. They live in

9:15

parts of the world that are hard to get

9:17

to. And so as a result, we are very

9:19

information poor about what these animals do in nature.

9:22

And so what we exploited in our

9:24

study is the spectacular resource in the

9:27

form of our natural history specimens or

9:29

specimens in our natural history museums where

9:31

there might be thousands of preserved

9:33

snake or lizard specimens that come from a

9:35

variety of sources. And you

9:37

might imagine that these things have

9:39

within their stomachs a sort of record of

9:42

what they've been eating. So we were able

9:44

to go to this vast sort of storehouse

9:47

of natural history specimens and look

9:49

inside their guts essentially and figure

9:51

out what these things were eating.

9:54

And I would add that that's really the

9:56

only way that we have about what a

9:58

lot of animals are doing ecologic. in terms

10:00

of diet and nature. So it's a really

10:02

important source of insight into what animals do

10:04

in the wild that frankly is very difficult

10:06

to get in the wild through what you

10:08

might think of as just a zoeing out

10:10

and observing nature. Is

10:12

it possible to watch today's snake

10:14

evolution as it happens quickly? And

10:17

I'm thinking specifically as we have

10:19

our climate crisis and things are

10:21

warming up, getting wetter, getting drier,

10:24

can we watch snakes evolve in our

10:26

lifespan? I would give two parts

10:28

of an answer to that. First, I would

10:30

say absolutely. We can see snakes evolving. In

10:33

fact, we can see

10:35

lots of things evolving in real time. Pretty much

10:37

everywhere we look when we take the time to

10:39

do a careful study that we see evolution unfolding

10:41

in real time within populations. But however,

10:43

I would caution that it's

10:46

really difficult to go beyond that to make

10:48

any kind of projections about whether snakes could

10:50

adapt to the pace of change in the

10:52

world around us today. I would say that

10:54

you're sort of looking at very different time

10:57

scales in terms of rate of evolution. We're

10:59

measuring things that are happening in our study over things

11:02

that are happening over millions of years. And right here,

11:04

we're changing things in the space of decades.

11:06

So it's just not the same sort

11:09

of time scale. I would be very

11:11

cautious about making any projections. I think

11:13

that I would not read into that as

11:15

saying that snakes are gonna be able to manage some

11:18

of these types of environmental changes. Has

11:20

your admiration for snakes increased as

11:23

you study them? Well, I

11:25

don't know. My admiration was pretty

11:27

high going into this. So I

11:30

think I have a newfound appreciation

11:32

for some dimensions of snake biology

11:35

that I would not

11:37

have maybe been aware of prior to

11:39

starting this. I would add to that,

11:41

we have tremendous areas of the snake or

11:43

the lizard, snake and lizard tree of life

11:46

that are very data deficient, where we have

11:48

very little information about the basic biology of

11:50

these animals in nature. And so, well, it

11:52

seems like we have a lot of data

11:54

in our paper and in fact, we do.

11:56

At the same time, it's really clear when

11:58

you sort of look at where the... data

12:00

are across the surface of the earth that we have

12:02

like diet data for like 15% of species. That

12:06

dating data is like with a lifetime of work

12:08

for many, many researchers. And

12:10

we're in a world where we're changing climate

12:12

very quickly and we don't have the most

12:14

basic information about many species of lizard's instincts

12:16

and many other things too. And

12:19

I do think that in 10 years, 20 years, 50 years

12:22

down the road, we are really going to regret

12:24

that we did not go all out at collecting

12:26

some of these information because a lot of these

12:28

populations and many of these species unfortunately are not

12:30

even going to be with us and we're going

12:33

to have a little understanding of what roles they're

12:35

playing within their systems. Well, Daniel,

12:37

I've learned so much about snakes today. I

12:39

want to thank you for taking time to

12:41

be with us. Thanks so much for having me on

12:43

the show. Great stuff. Daniel

12:45

Robosky, evolutionary biologist and curator

12:48

at the Museum of Zoology that's

12:50

at the University of Michigan and

12:52

famous Ann Arbor. This

12:54

week on the New Yorker Radio Hour,

12:57

staff writer Evan Osnos on President Joe

12:59

Biden and his very personal rematch against

13:01

Donald Trump. He feels almost viscerally this

13:03

contempt for Trump and what Trump did

13:05

to the country. And after all, let's

13:08

remember what Trump did to Joe Biden.

13:10

I mean, he didn't just try to

13:12

steal this election from Biden's perspective.

13:14

He tried to steal it from him. Evan

13:17

Osnos on the New Yorker Radio Hour

13:19

from WNYC Studios. Listen wherever you get

13:21

your podcasts. If

13:27

you've heard recordings of whale songs,

13:29

you know that they can be

13:32

both beautiful and haunting. Really

13:52

cool. You know what? The way

13:54

that baleen whales like humpback and minke

13:56

whales, the exact mechanisms whales

13:58

use to make those noises, we

14:01

really never understood, that

14:03

is, as they say, until now.

14:06

A recent study in the journal

14:08

Nature investigates the mysteries of the

14:10

whale larynx and its role in

14:12

whale songs. Joining me to

14:14

talk about it is Dr. Cohen Ellemans. He's

14:16

a professor of bioacoustics and animal

14:19

behavior at the University of Southern

14:21

Denmark in Odense, Denmark. Welcome back

14:23

to Science Friday. Thanks

14:25

so much for having me again. It's always a pleasure. It's

14:27

so nice of you to say that. It's

14:30

amazing to me that we didn't know how

14:33

whales made those sounds. Why is that? Well,

14:35

it's difficult for several reasons. First of all,

14:38

if you put a microphone or an underwater

14:40

microphone, which is called a hydrophone, in the

14:42

water, you pick up sounds from

14:44

very far away because sound travels

14:47

so fast and so far in water. It's

14:49

actually quite difficult to say, if you're

14:52

recording something, that it is a

14:54

certain animal that is in the area because you

14:56

see it. It could come from 10 miles away

14:58

or even further. Since the last

15:00

20 years or so, people started to develop tags you

15:02

can put on a whale. And since

15:04

then, it becomes easier to actually associate

15:07

a certain sound with a specific species.

15:10

So that's one thing. The other thing is

15:12

that it's very hard to study physiology of whales. So

15:14

first, we've hunted them down to near extinction. So

15:17

they're all protected now. And

15:19

the other thing, when there is a whale that's, for

15:21

example, beaches and dyes, then they typically

15:23

rot so fast when they're on the beach

15:25

because you cannot get that fast enough, for

15:27

example, that actually the tissue is

15:29

so rotten, you cannot see so much from it

15:31

or you cannot learn so much from it in

15:33

terms of physiology. Well, then what made it possible

15:35

for you to study them now? So

15:37

we were extremely lucky that we

15:39

have a very active stranding network

15:41

in Denmark and also in Scotland,

15:43

where basically people alerted us to

15:45

a whale that beached. This is the first one

15:48

was in 2018, actually. And

15:51

it beached in very bad conditions for the whale,

15:53

of course, but in very good conditions for us,

15:55

close to a harbor, very cold weather, cold water.

15:58

And so we could get there very fast and get very... fresh

16:00

tissue that. So you

16:02

were able to look at the larynx of these

16:04

beached whales. How similar is

16:06

a giant whale throat to mine

16:08

or yours? Well, it's quite different. And

16:11

that was actually, that was partially known because

16:13

people have studied the anatomy for whales for

16:15

quite a long time and also the larynx.

16:18

What is very different is that the

16:21

little cartilage is that move our vocal

16:23

folds together and as such allow speech.

16:26

They are very different in the whale.

16:28

They've become massive tubes that basically form

16:30

a U shape and this

16:32

U shape is largely immobile and we think

16:35

that's the case because then it opens the

16:37

airwaves when these animals have to breathe on

16:39

the surface. So you have massive flows, air

16:41

flows coming back and forth when they surface

16:43

and breathe. And if you then

16:45

have vocal folds sitting in the way, they would start to

16:47

flap and actually be annoying. You don't want that. But

16:51

they're underwater and they make these sounds which means

16:53

they still have to blow air through their larynx.

16:55

How do they do that? Yeah, so what we

16:57

think is that what they do is they still

17:00

push air from their lungs through their larynx

17:02

and this goes into a sack that's called

17:04

the laryngeal sack. And this sack collects all

17:07

the air and then a big muscle surrounding

17:09

it pushes it basically back through the larynx,

17:11

back to the lungs and this way they

17:13

can recycle the same air back and forth

17:15

without surfacing and actually taking a

17:18

new fresh breath. Now

17:20

you're talking about the baleen whales, right? Do

17:22

the other kinds of whales that don't have

17:25

the baleen in them, do they do the

17:27

same thing? No, so actually last year

17:29

we had a paper where we

17:31

showed how the tooth whales and that

17:33

involves the dolphins, the killer whales and

17:35

for example sperm whales, how they make

17:37

their sounds. And they evolve completely novel

17:39

structures that sit in their nose. And

17:42

so they've made a totally different solution to

17:44

this problem. How do you make sound on the water when

17:46

you hold your breath? Wow,

17:48

okay, so let's talk about the whale

17:51

that washed up that you used.

17:53

How do you go about proving with a

17:55

dead whale that this is how it makes the

17:57

sounds? Tell me about your setup. So

18:00

first we started the anatomy in great detail.

18:02

We first learned this down, we studied our

18:04

anatomy, and then we build a setup where

18:07

we can basically in very controlled conditions

18:09

can blow air through the larynx. And

18:11

that's where you can study the vibrating

18:13

structures that generate sound. Now,

18:16

and if the tissue is fresh, then actually the

18:18

properties are very similar to in the living whale. And

18:20

that means that if you get vibrations, they should be

18:22

the same as what the whale does in vivo. And

18:25

that's what we also saw. So it took

18:27

a while to build such a setup because

18:29

it's not because it's big, but because it

18:31

acquired all kinds of adaptations because the larynge

18:34

is so huge. And we

18:36

could measure very accurately things like flow and

18:38

pressure and with high-speed cameras, we could film

18:40

things that vibrate. And we

18:42

could show that the vibrations were exactly the

18:44

same frequency as you see in the living

18:46

whale. Well, you got to tell me how you MacGyver'd

18:48

this thing. Yeah, there

18:51

was a nice crossover between MacGyver

18:53

and scientific research. So we

18:55

needed a setup where we have very high flows of

18:57

air with low pressure. And that's actually, that

18:59

was a bit complicated. So we ended up using,

19:02

we first wanted to try weather balloons that didn't

19:04

work. And then the end we'd use party balloons,

19:06

basically, that have a really big volume and a

19:09

very low pressure. And then we could

19:11

let the air out of these things

19:13

while measuring pressure and flow very accurately.

19:15

And that powered very accurately the larynge.

19:18

Wow, so you had a really close

19:20

accurate sound of how the living whales

19:22

would do it. Yeah, so what

19:24

we can mimic really accurately is sort of

19:27

the lowest frequencies these animals can make because

19:29

then the tissues are not so

19:31

stiff and they vibrate at the lowest

19:33

frequency. What we couldn't do in

19:35

the lab was to then activate muscles,

19:37

for example, because the tissue is dead. And

19:41

to do that, we made computational models where

19:43

we basically made a full 3D larynge

19:46

in the computer, could blow air past

19:48

it, confirm our first experiments, but

19:50

then we can also start simulating activity

19:52

of muscles, for example. So with these computational

19:55

models, we could now show how

19:57

high frequency sounds you could generate with

19:59

this. This mechanism. Okay,

20:02

lucky for us you have provided

20:04

us with some of the sounds

20:06

you created. so let's listen. I'll

20:27

doctor Elements what are we listening to

20:29

when we have you ever listen to

20:31

his ex year the acceleration of of

20:33

of a part of the vibrating tissue

20:35

and says he made into sound. That.

20:38

Was really low frequency. my son is

20:40

very low frequency. Yes. And

20:42

that's realistic. Daily yes

20:44

it is with of a sigh whale

20:46

and aside will make she's very low

20:48

frequency even sweeps and the and that's

20:50

exactly basically what these animals in. And

20:53

of course the whales often have these

20:55

sounds in a very high higher point

20:57

for higher registers. Does your research account

20:59

for these two? Yes, Oh partially that

21:02

all these baleen whales all sixteen species

21:04

may very low frequency sounds. And if

21:06

we lived in details as anatomy that

21:08

is studies animals we see that this

21:10

discussion where we show know that generates

21:12

the sound. Is there is

21:15

present in all these species? So you think

21:17

that's ancestral? But

21:19

a few species like the well known

21:21

Hum Back but also bowhead whales for

21:23

example there and very well known for

21:25

their song that very high frequency and

21:27

added added and I've found is that

21:29

exceed the earth know targeted as big

21:31

you shape. In these species is

21:34

were able again to come together until

21:36

it again looks a little bit like

21:38

human vocal folds and that makes again

21:40

definitely sounds. And recent death

21:42

with mechanism of responsible for the sky

21:44

high frequencies in indo species. That.

21:47

we were not able to to show because

21:49

we couldn't simulate that in the lab i

21:51

see ah of course there is a big

21:54

variation in in the human vocal range if

21:56

god james earl jones on one side it's

21:58

have an opera soprano the other,

22:00

do whales have a similar range

22:03

like that? Well, actually, I wouldn't

22:05

know. We don't know enough yet about how individuals

22:07

perform. We have tagged individuals and can see what

22:09

they can do. But there's lots

22:11

of mysteries out there. I talked to

22:14

a colleague last week and, for example, a few

22:16

of the whale species seem to go lower and

22:18

lower and lower in frequency over the last years.

22:20

Everybody's really puzzled how this could work. So there's

22:22

lots of open questions there. Your

22:25

research says that there are some sort of

22:27

limits on how and where whales can sing.

22:30

Is that correct? Yeah. So

22:32

we show now that this U-shape

22:34

against the cushion mechanism is

22:36

limited in frequency range. So first, it's really

22:38

cool because it allowed the whales to make

22:40

sound while holding their breath on the water.

22:42

And it allowed them to live, basically, and

22:44

evolve. But it also

22:46

is very limited. And it limits them to

22:49

probably frequencies, let's say, 5 hertz to 300

22:51

hertz. So that's one limit. Another

22:53

limit is that we could now measure how

22:55

much air they need actually to make these

22:57

vocalizations. And because we can estimate

23:00

the amount of air available in a whale

23:02

and also scaling with size and so on,

23:04

we could estimate how deep can you now

23:06

take, basically, the system and still have enough

23:09

volume to make it sound. When we

23:11

did these simple models, it basically showed that about 100 meters

23:13

or so deeper than that, the whales, they don't

23:16

have enough air to basically make sound. So

23:18

there is a frequency range and also

23:20

depth range where these animals are able to

23:22

make sound. It depends on how long the

23:24

vocalization is. But we estimate at about 100 meters, this doesn't

23:27

work anymore. That's not far down, is

23:30

it? It is

23:32

for us. It's very far down. But

23:35

for a whale, it's really not. It's

23:37

really the surface of the ocean. And a

23:40

lot of whales can dive much deeper. But so we

23:42

really now give a

23:44

constraint that the vocalizations are mostly restrained

23:46

to the surface. So when they want

23:48

to talk to each other or vocalize,

23:50

they have to come closer to the surface to do

23:53

that. Yes. And that's also

23:55

actually that's what we predict. And that's

23:57

also consistent with the data that people

23:59

are getting. from these tags where you

24:01

put a tag on a whale. And

24:04

those animals typically sink below 20 meters

24:06

actually or even shallower. And

24:08

what about boat noise? Does that overlap with

24:10

the sounds the whales are making? Yes,

24:13

absolutely. Actually the recording you just played of this

24:15

whale in the lab really reminds you of boats,

24:17

right? And that's also one of the big problems.

24:19

So now that range we

24:21

show where the animals are able

24:24

to communicate is exactly or like

24:26

very tightly overlapping with the

24:28

range where we make most noise on the water

24:30

or a lot of noise on the water and

24:32

particularly shipping. So they can't sing

24:34

higher to be heard over the boats then? There

24:38

is limitations, physiological limitations to how loud

24:40

you can sing basically. That's one. And

24:42

now we also showed us a limitation

24:44

to the frequency range and the depth.

24:47

So all these three together limits our

24:50

physiological limitations to these animals. Okay so tell

24:52

me as I wrap up here, tell me

24:54

what more do you want to know about

24:56

this? Well one thing

24:58

that's really open sales, how the humpbacks, the

25:00

male and also female humpbacks make these very

25:02

high frequency sounds. That would be really fun

25:04

to figure out. Well

25:07

I want to thank you for coming back and

25:09

keeping us informed about whales. Thank

25:11

you so much. Take care. Always a

25:14

pleasure to talk to you. Cohen Ellemann

25:16

is professor of biocoustics and animal behavior

25:18

at the University of Southern Denmark

25:20

in Odense, Denmark. That's

25:23

it for today. Lots of folks

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help make the show happen including

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John Dankowski, Kathleen Davis, Dean Petersmith,

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Robin Kasmer and many more. Tomorrow

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a conversation with a young researcher

25:35

studying Parkinson's disease. I'm

25:37

Sci-Fry producer Charles Bergquist. Thanks for listening.

25:39

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