Nature’s best vibrators - ABC News & Headlines – Australian Broadcasting Corporation

We have been listening to insects vibrating (or rubbing themselves) our whole lives. But what do WE sound like to them? How does our noise pollution impact nature's vibrators? 

Dr. Perry Beasley Hall, Adelaide University.

Ernesto Caliari Pinheiro, Acoustic biologist, Brazil.

Professor Mario Vallejo-Marin, University of Uppsala, Sweden. 

Lisa Schonberg, Ecological sound artist, New York.

Professor Link Olson, University of Alaska Museum.

Dr Andy Reid, University of Strathclyde, Scotland.

Dr Ying Luo, Australian National Insect Collection. 

Son of a Bee by Dusty Dubs, David Rentz and Vicki Powys.

This episode of What the Duck?! was produced on the land of the Wadawarrung and Kaurna people.

Find more episodes of the ABC podcast, What the Duck?! with the always curious Dr Ann Jones exploring the mysteries of nature on ABC Listen (Australia) or wherever you get your podcasts. You'll learn more about the weird and unusual aspects of our natural world in a quirky, fun way with easy to understand science.

This content was transcribed automatically and may contain errors. Read more on how the ABC is automatically creating audio transcripts .

Speaker 1ABC Listen, podcasts, radio, news, music and more.

Speaker 2Nobody really knew what was going on.

Speaker 3More than 100 people fall ill after visiting a new aquarium. A dangerous infection emerges, but no-one can find the source. And in another outbreak, there's a controversial theory involving mozzies, possums and flesh-eating bacteria. I'm Belinda Smith. Join me for outbreaks. Search for science fiction on ABC Listen or wherever you get your podcasts.

Speaker 4Oh, hello you. Thank you for clicking on me. I'm in it. I don't make it weird. Speaking of, I'm Dr Anne Jones and in this episode I have taken the what-the-duck search for fantastical animals to new depths, finding the bottom of the barrel and still digging. We are going to be talking about naked mole rats. These are tiny, savalloy-sized, pink, fleshy rodents that live underground in Africa. They don't feel pain. They inbreed. They survive almost without oxygen and sing when they go to the toilet. Same. Oh, and they might just hold the key to being forever young. And they're also the animal that holds the prize for most resemblance of a human phallus. So if you have young, sensitive ears with you or perhaps you are of sensitive disposition yourself, please know that I go through many creative ways in this program to describe an animal that looks like a penis. It is very funny, but only if you're up for it. So proceed with your appropriate caution or jump right in. You're outside on a warm night. You feel the breeze and you wave away a stray mozzie and notice that the insects are squealing. They're absolutely catawalling their guts out. You imagine hundreds of small green things, mouths open like opera singers, just screaming. And I've got bad news. They're not screaming. They're rubbing themselves. What the Duck is going there. I'm Anne Jones and I make this program which meanders into the wildest places to find out the wildest facts that make you spit out your tea. And the tea? The tea is there's a lot more self-stimulation going on in the natural world than I ever imagined.

Speaker 5We also have grasshopper stridulation.

Speaker 4Peri Beasley Hall is an evolutionary biologist at the University of Adelaide. So there's quite

Speaker 5a different call sound because the crickets are rubbing their wings together whereas the grasshoppers are rubbing their legs onto their wings.

Speaker 4Grasshoppers and crickets were not really blessed when it came to vocal cords, but they do have a good set of legs and they've learnt how to use them to advertise to mates.

Speaker 5So stridulation is just one type of noise that insects can make, but stridulation specifically refers to rubbing two body parts together to make that vibration and make that chirping sound.

Speaker 4But it's not always quite so pleasant. Take the loud green shield-backed katydid from Newcastle, recorded by legendary entomologist David Rents. Or even better, the winged marauding shield-backed katydid from Dark Peak in South Australia, a description which absolutely sounds like Australia Gothic come to life. And look, whether it's pleasant or not to our ears is inconsequential.

Speaker 5Stridulation is just another form of what we would call intraspecific communication, so communicating with other members of your own species. That can be to attract a mate, so if males are saying, hey females, I'm here, you know, come and mate with me. Or they're telling other males, go away, this is my territory.

Speaker 4That's not radio interference, it's a katydid from Coffin Bay.

Speaker 5There are some species in which both sexes will stridulate, but normally acoustic communication is almost entirely a male trait. We do know that all crickets have had the ability to produce some degree of noise, at least the males in those species, for about 300 million years, so it's a really old trait that they've always had.

Speaker 4That's around the same time as modern humans appear in the fossil records, so we have potentially been lulled to sleep by this sound for as long as we have existed. I wonder what we sound like to them. Yeah,

Speaker 5sure, sure. So crickets have hearing organs not on their bodies or their trunks, but actually on their front legs. Sorry, what?

Speaker 4Their ears are on their legs.

Speaker 5Yeah, so they'll place their front legs on the ground, and then they'll hear those noises through the vibration in the ground or directly in the air. They're very sensitive to vibration. If you stomp on the ground, for example, and a cricket's calling, it will almost always stop because it's been startled by what it can feel from your feet.

Speaker 4And if my stomping can produce that impact, then what about other human noises?

Speaker 7Oh, OK. So my full name is Ernesto

Speaker 4Caliari Pinheiro. Ernesto Caliari Pinheiro is an acoustic biologist from Brazil.

Speaker 7We would try to figure out if the noise from mining trucks, from one of the largest open mines in the world, how it would affect species of crickets.

Speaker 4So we need to get rid of these Australian crickets and get some Brazilian ones. Ernesto studied three species of crickets near the Brucatul mine in Brazil, which had something like 30 million tonnes of iron ore extracted from it every single year it was open.

Speaker 7Using some acoustic analysis software, I could see an audio cut from five in the afternoon to five in the morning. And sub-sample those to see the times where the trucks passed and then analyse the spectrogram of the cricket's calling.

Speaker 7We could see that one of them, it would interrupt its calling activity in 90% of the events that a truck passed nearby. Others would try to chirp while the truck was passing, but its sound was completely masked by the sound of the truck passing.

Speaker 4Some species would stop calling completely, and others would still be rubbing away, stridulating their little hearts out, trying to find a girlfriend, but not being heard at all.

Speaker 7Basically means the whole energy the animal invested to the calling behaviour was gone to waste. Stridulation is very high intensity energy-wise activity. So the animal basically loses most of its energy to emit some sound that won't attract any female crickets, because the whole sound was masked by the truck passing.

Speaker 4It's one of those things, right, where you're like, what does it matter, it's just some crickets. But when it comes to anthropogenic noise pollution, could crickets be the canary in the gold mine?

Speaker 7The impact of anthropogenic noise should be considered while making conservation efforts in general. But I think the most correct way to go forward with this is making some changes to, I guess, legislations about the processes for constructing open mine near wildlife. Should be considered the amount of noise that is emitted before, during and after the implementation of these construction sites. So that doesn't happen anymore. But I guess that's really a topic to hope.

Speaker 4Cheese and crackers, this isn't what I was thinking of when I pitched an episode on nature's vibrators, everyone. Son of a bee. Welcome back to Antenna Radio, where we bring you the insect hits. Oh, and that's Dusty Dubs with Son of a Bee. I hope it's vibrating your spermothecas, Queens.

Speaker 8It turns out that bees produce different types of vibrations. Mechanism responsible of these bee vibrations is the thorax, specifically the muscles that normally activate the wings during flight.

Speaker 4This is Mario Vallejo Marin, professor of ecological botany at the University of Uppsala. Well, actually, that's not, that's a buff-tailed bumblebee. But this, this is Mario.

Speaker 8Most basic is buzzing is sort of a byproduct of the bee flapping its wings up and down. But bees in particular are also able to deploy buses without moving the wings. And this sort of opens up a whole repertoire of behavioral tools that the bees use for different purposes.

Speaker 4Bees can use vibrations to thermoregulate, to communicate, to search for mates, or even as an alarm to warn off predators. So it's not just, you know, buzzing around.

Speaker 8And of course, and this is my favorite, some bees use vibrations to forage for pollen from certain types of flowers. What happens is that the bee lands on the flower and grabs the flower, usually with its mandibles and legs, and then curls the body around the flower parts that contain the pollen, the anthers, and then it begins vibrating very vigorously.

Speaker 4It's called buzz pollination.

Speaker 8And these vibrations are sort of transmitted from the body of the bee onto the flower and eventually making the pollen grain inside these floral structures to shake and bounce up and down.

Speaker 4Okay, this is sounding like a sex thing.

Speaker 8And this bouncing up and down of the pollen grains transfer energy to them, and eventually the pollen grains come shooting out.

Speaker 4My God, it is a sex thing.

Speaker 8Shooting out of small openings at the tip of these floral structures. And so the bee receives on its belly, on its ventral side, a rain of pollen, and then they can collect it from there.

Speaker 4It's a literal ejaculation of pollen, if the internet is to be believed. So buzz pollination is a sort of efficiency tool. If you buzz pollinate, you can get what you want quicker. A vibrator is a bit quicker, so it makes sense.

Speaker 8Yes, absolutely. It's a very effective and efficient method of pollen extraction if you can vibrate that flower.

Speaker 4Now, if you go on the internet, you might find a reference to the fact that buzz pollination needs to happen exactly at the frequency of middle C for it to work. But is that actually broadly true, even for Australian bees? Wildlife recordist and researcher Vicki Powers risked severe hay fever by investigating this on her bush block in the Kapiti Valley. She found all sorts of wonderful things, including that bee size was not related to the pollination buzz pitch, nor was the flower size, and it didn't have to be middle C. In fact, the buzz pollination she recorded ranged across a full octave in musical terms. This one is a carpenter bee, and if you can hear, it's got a lower flying buzz as it zooms around, and a higher pollination buzz where it's shaking the pollen from the flowers. And though it might sound as if it's the actual wings which were to make the bee sound, it's not.

Speaker 8What happens is that the large muscles inside the thorax of the bee start contracting, and bees have sort of two pairs of muscles that contract antagonistically, and these contractions cause the thorax of the bee to deform.

Speaker 4Think wobble board, but where the board is a tiny exoskeleton of a bee clicking inwards and outwards.

Speaker 8And this compression and relaxation of the thorax is what produces the mechanical vibrations. One cool thing about these thoracic vibrations by bees is that they are able to contract them at a very high rate, several times higher than the rate at which the bee can fire the neurons telling those muscles to contract.

Speaker 4The bee's muscles work faster than its brain. Epic. But how do you actually measure and study tiny little bee thorax vibrations?

Speaker 8Very recently we have begun using miniature-sized robots that produce vibrations.

Speaker 4Ah yes, small vibrating robots.

Speaker 8Yeah, it works surprisingly well, because the basic mechanism of buzz pollination is really simple. You just need to shake the flower. So the robots have been very useful in making these shakers to go from what we used to use before, which was a heavy machine that weighed a kilo or two kilograms, to these bee-sized shakers that we can clip on flowers and use to study the consequences of those vibrations on pollen release. Sometimes we want to study how the pollen jumps out of the flower. So what we do is that we use these mechanical shakers and high-speed cameras to capture frame by frame the trajectory of these pollen grains as they are ejected from the flower.

Speaker 4Excuse me as I just step outside for a moment. I've been working in the garden a lot lately, which involves moving around rocks. And look at what is happening here. This is maybe a hundred bull ants who are very, very, very angry with me. That's a rufous whistler, ignore that for a minute. Because that ant sound is the sound of them swarming out of the nest. I inadvertently made a hole in the side of it when I was moving a rock, and they sound like static, or like water trickling.

Speaker 4There are tens of thousands of species of ants in the world, but only a few of the sub-families have stridulatory organs, that is, an apparatus that makes sound by rubbing. Lisa Schoenberg is an ecological sound artist. With

Speaker 9ants, they generally sound like... ... They're kind of like that.

Speaker 4It sounds a bit as if you're trying to get a really stuck-on bit of bird poo off your windscreen with one of those scrapers, but I don't think that's how the ants are making the sound.

Speaker 4abdomen. That's the back segment of the body, the butt.

Speaker 9And they move the abdomen up and down generally to make those sounds happen.

Speaker 9I never thought of it that way. It's working for ants. In general, these sounds, you can't hear them without the aid of technology.

Speaker 4And what are they trying to communicate?

Speaker 9It's been demonstrated that ants use stridulatory sounds for purposes of alarm or defense. They also use it for recruitment purposes. If an ant finds food, she is generally going to tell other ants to come and join and to get that food. You'll see one ant show up, and then you'll see many ants there soon after.

Speaker 4Next time you're horrified by a swarm of ants coming for your bathonged feet, remember that actually they may be making a sound like a horde of tiny kittens learning how to use their feet for the first time. It's just you can't hear it. And when I think about the vibrations of the animal world, I do think about purring. But that's not stridulation. It is vibration. Apparently it's because domestic cats have an extra layer of fatty tissue on their vocal cords that they can draw air over. But there is a mammal that can stridulate.

Speaker 6They are about the size of a gerbil or a hamster, but otherwise entirely bizarre looking.

Speaker 4That's Link Olson, curator of mammals at the University of Alaska Museum, and he's talking about the lowland street tenrec. Imagine an elephant shrew that got its little schnoz stuck in an electric socket and absolutely looks like it's done a cartoon poof. It's about 14 centimetres long, and if you want to see one, good luck, you'll have to go to Madagascar.

Speaker 6That's one of the oddballs that really doesn't look like any other living mammal on earth. They are characterized by the very striking black and white quills and hair that give them a striped appearance. And those barbs mean that when a quill gets into a predator, those quills come out relatively easily. And then they go deeper and deeper with every muscle contraction of whatever it is that has the quill in it. So they're very effective anti-predator mechanisms. I learned the hard way to use leather gloves when handling hemicentres.

Speaker 4Good to know. But the quills are used for more than just warding off predators or researchers. There's

Speaker 6a very specialized group of quills in their lower lumbar region, so in their lower back, that are shorter and fatter. They're not as barbed, and they don't detach as easily. And underlying those quills is a special muscle that is used to vibrate those quills together very quickly, and we call that stridulation, of course. And they seem to use that to communicate to one another as family groups when they're foraging. It is very poorly known, and it is even more poorly studied.

Speaker 4And that's probably in part due to the fact that a lot of the sound of the tenrec stridulations are ultrasonic, that is, above human hearing.

Speaker 6They are just so fascinatingly weird, and that's just one of the weird things about them. As far as I know, Hemicentides is the only mammal to truly stridulate. It's a pretty unique form of communication in mammals.

Speaker 4Again, learning heaps today, it's super unusual for a mammal to stridulate, but for invertebrates, that's another story. Even when they're underwater, where the water boatmen rule, carnivorous, propelled by specialized legs that move like oars and have hairy paddles on them, water boatmen grasp a bubble of air like a bear hug and dive down underwater, using that bubble to breathe while they're down there. Andy Reid is in engineering at the University of Strathclyde, and he was interested in water boatmen making sound underwater, which is apt because Andy actually sounds like he's underwater thanks to the Internet. It's

Speaker 1got the loudest meeting call for its body weight of any animal. I think it's slightly quieter than a pistol shrimp.

Speaker 4Which apparently get up to 190 decibels. That's much louder than your co-worker's phone conversation on speakerphone.

Speaker 1But it makes this noise by a stridule which is attached to the right palimere of its penis, essentially. Did

Speaker 4that wonderfully accented engineer just say that it makes the noise with its penis?

Speaker 1To the right palimere of its penis, essentially. Oh

Speaker 1Which it rubs against its abdomen.

Speaker 2Perfect. The water boatmen are producing their sounds by rubbing their penis against their abdomen.

Speaker 4Ah, there it is confirmed. Ying Law is an entomologist based at the Australian National Insect Collection.

Speaker 2So their penis has these ridges on it. There are also ridges on their abdomen. So by rubbing those two things together, they can create sound. So

Speaker 4it's got two ridged surfaces that it rubs furiously together. And like, okay, this may be too much detail, but does it rub its penis on its abdomen using an arm, or is it a penis-led activity?

Speaker 2This is unconfirmed. Based on my brief period of research, unknown. I think it's a penis-led activity. I don't think insects use their legs to do that.

Speaker 4Think of the water boatman sound like rock hard abadabas, like one of those old washing board stomachs getting scraped, but with a penis. Simple.

Speaker 1So, I mean, generally with stridulation, when you're making a pure call, you are trying to make the call as efficiently as you possibly can. The most efficient thing to make the noise with is something you can just move back and forward.

Speaker 4Right, it's all about efficiency. And would you like to hear the product of the water boatman's self-congratulatory, very efficient penis waggling? Yeah, it sounds like someone has left a phone off a receiver in another room, and you can just hear the tiny, tiny voice coming through.

Speaker 1But it doesn't make the sound entirely of this noise. What it does is it uses the stridulation of his penis to resonate the bubble that it uses for its air supply, and it's this bubble resonance which carries this incredibly loud meeting call out into the world.

Speaker 4This is a way of getting around the fact that you're a tiny little animal that needs to make a big noise. The species of water boatman that Andy and his colleagues studied was less than a millimetre long. A millimetre. Tiny, tiny. So it used the bubble not just to breathe underwater, but as an amplifier for its stridulation. It's ingenious. A tiny little penis that is capable of very big things. And what do all the females actually think of all this penis play anyway? Nobody's

Speaker 1actually found the ears on the female of this particular species.

Speaker 4They haven't found the female's ears. Oh, jeez. Yes, I've got an idea of where I

Speaker 1think they are. But no, I haven't found them.

Speaker 4I'm not even going to go there.

Speaker 2There's also a moth that does it, and excitingly, it's an Australian moth.

Speaker 4I found an article online about this, and the subtitle of that article is Good Grief. That gives you an idea of what it looks like in action.

Speaker 2The scientific name is Synctonaca eris... Let's see. Maybe I should find its common name.

Speaker 4It's called the wanky moth.

Speaker 2Wanky moth? We'll just give one right now. Singing genitalia moth. So these moths, what they do is the males, so it's always the males trying to perform for the females to get them to know that they're there. So the males dilate and expand their genitalia.

Speaker 4They literally dilate one bit out into a taut little tent, and the other bit of genitalia is used as a stridule to rub it like hell. They fly to the top of a gum tree, they spread their wings, raise their erect genitals to the heavens, and go hell for leather.

Speaker 2As with the water boatmen, they're stridulating, so they're using their genitalia to produce sound. However, unfortunately, we can't actually hear it with our ears. The sound range that they're producing it at is kind of like a bat call. We can't actually hear it, but you could hear it if you had, you know, like a bat detector, which can be used to hear ultrasonic sounds.

Speaker 4Challenge accepted. And that's where you leave me, dear listener, out in the bush in the middle of the night with a bat detector, trying to see if I can find a moth that's rubbing its swollen genitals so hard that it's making an ultrasonic sound. What the Duck is an ABC Science podcast. I'm Anne Jones, and I produce the podcast with Petria Ladgrove. We make this program on the lands of the Wadawurrung and Kaurna people.