Welcome to Creature Future production of iHeartRadio.

I'm your host of Many Parasites, Katie Golden.

I studied psychology and evolutionary biology, and today on the show, I'm answering your questions.

That's right, your questions about animal behavior, about biology, about sometimes pets.

Uh.

You can send me your questions at Creature featurepot at gmail dot com and I do my best to answer them.

Got some really good questions this time around, so let's get right into it.

Here is the question.

I've been breathing here since shortly after I was born, so maybe it's hard to think about having gills.

We can't smell anything without drawing air through our nostrils.

How to fish smell?

And how do shark smell blood in the water for miles away?

Do they smell with their gills or something?

This is from j T.

And I do want to point out the title of the email because it's very funny.

It is do fish smell fishy to fish?

So very good question, and yes, so fish do smell fishy to fish in the sense that fish can smell other fish and other things in the water, So this is a great question.

Smells work a little differently under water.

So up here in the air, molecules are carried by the air.

We inhale them and they go up in our nostrils and they bind two olfactory receptors in our nasal cavity, and so that is how we will smell something.

The molecule will lock on, that'll trigger a chain reaction of neural cells to our brain, and then we identify something as a smell.

And obviously the strength at which we can detect smells depends on our species.

Humans are decent smellers, We're not amazing.

Something like a dog is really really good, and you can see with a dog they have a lot of techniques that involve the passage of air in terms of smelling things.

So you see a dog kind of sniffing the ground and then exhale like snort out.

That doesn't mean that the dog doesn't like the smell.

Means the dog is trying to get a better whiff of it, with the air going both into the nostril and then those molecules binding to receptors and then forcing it back out of the nostrils once again, the air carrying the molecules passing over these sensitive receptors once again, and then they have a second pass at picking up even more molecules, and they have really really sensitive sense of smell.

So all of that is enabled by the air carrying these molecules.

But underwater you can have a very similar thing happening.

So in the water, obviously you don't have molecules carried by the air.

You have them carried by the water.

So fish receive chemical information through the water.

It's a very good hypothesis that there might be olfactory receptors in their gills, given that the waters they have to have water pass over those anyway, so it's a good spot to have some receptors there.

In fact, they do have receptors there.

Technically they're not considered olfactory receptors.

They are taste receptors in their gills.

In effect, it's a very similar result where these receptors are picking up on chemicals in the water, chemicals being any kind of like compound, any molecule, and are sensing that.

It's just like they're the way that we've mapped sort of the fish brain.

Some we categorize as olfactory receptors and some as taste receptors, just like in humans.

But yeah, taste and smell are very very much connected, very similar in terms of how it works in terms of things binding to receptors.

So technically the receptors that they have in their gills are taste receptors.

But they do have noses.

I know it doesn't look like it, but if you look at a fish or close up, they have nostrils and those open up to olfactory chambers.

Their nostrils, unlike ours, are only used for smells.

They do not breathe through these nostrils.

Their gills they use for breathing, as in, they take in water and the water flows over these gill structures that collect oxygen molecules from the water that the fish can use.

The nostrils don't do that.

The nostrils collect water solely for the purpose of smelling it by the water flowing through, and again they pick up these molecules, but instead of it being oxygen, they're picking up any kind of like small molecule that combined to these olfactory or scent receptors in this nasal cavity.

And then since what that is, so water containing molecules of things like amino acids or other chemicals enter into this old factory chamber and bind to the receptors in there.

This exact same thing goes for sharks.

So sharks are a type of fish.

They have a similar situation with their nostrils where the water goes in and carries these molecules with it and then binds to the olfactory receptors.

So they may pick up on say, amino acid proteins from blood which flow into their nostrils and bind to their receptors, allowing them to follow its scent from up to around a quarter of a mile away.

They're very, very sensitive to this.

But it's not true that they can smell a drop of blood a mile away.

The scent would be too diffuse before reaching them, because you think about it, the physics of it, the molecules from that blood droplet have to diffuse use far away enough that the shark can get, you know, some amount of the molecules, these little proteins from the blood up in its nostrils.

So if it's too far away, just mechanically speaking, it's not feasible.

But the sensitivity of a nose can be that it picks up on a very small number of these molecules, where for maybe other fish or other animals, it would be way too low of a concentration for them to pick up on it, but they can smell it.

So like the difference between say, humans and dogs, we need a higher concentration of these molecules to actually like have it trigger a response in us, whereas with dogs they have more receptors, they're able to pick up on lower concentrations of molecules in the air.

So a similar thing with sharks, who are very sensitive smellers, but not maybe as much as the sort of internet or old wives myths have about them being able to like smell a drop of blood from miles away.

So there are other animals in the ocean aside from bony fish, and they have different methods of smelling, but it follows the same principle of picking up molecules from the water that then bind to receptors.

So, for example, sea slugs have a rhinophores, which are these horn like protrusions that pick up on chemicals in the water and it binds to them and it's you know, sort of a form of taste or form of smell.

Octopuses have dimples in their mantles, so the mantle is the main part of the octopus and they have these little these little indentations, very very tiny pores where they can detect smells and you know, so like the water will flow over their mantle and it'll pick up on these molecules and they'll bind to these receptors.

Their tentacles have taste receptors to further explore their environment, so like they have to for their tentacles to pick up on tastes and stuff like, you know, it's more of a tactile thing.

They can like touch things and that will help them to pick up on the taste of an object or the chemicals that are coming off from it, and then other like all sorts of different animals have sort of different organs or places upon which these receptors are, but the mechanics of it are pretty similar, where it's like a molecule binding to a receptor.

So for example, starfish have olfactory receptors all over their skin, but it's the same technique where the water passes over it, molecule binds to a receptor and then that they perceive that they have the feedback of like oh, here's something, and they can move towards it or away from it, depending on what it is so great question.

Yes, fishes can smell, both smell as in being smelly and smell as in detect odors.

Onto the next listener question.

Hi Katie.

Recently I've seen a post circulating online claiming that hyenas can grow a winter coat when exposed to colder climates.

I cannot find proof one way or another and was hoping you could help me find some evidence.

Thank you for the help, longtime listener and zookeeper.

This is from k Ewart and there is a Reddit post that they sent as well.

And I'm looking at a fluffy hyena who appears to be sort of buy some rocks and also buy some snow.

So this is a This is a great question.

Always, if you have there's like some kind of internet claim about animals and you're sort of curious about it, please do contact me because I love digging into these things, especially when it's like something you just see all over and there's no never like a link to a study or an article or some experts say anything about it.

So let's investigate this.

Do hyenas grow winter coats?

A social media post also makes a claim that that hyenas can grow winter coats?

Because they used to roam Europe.

So first let's let's explore the second claim, because that's that one's easier to address.

We're hyenas ever in Europe.

This part is true.

So spotted hyenas, as well as extinct relatives of hyenas, including the giant cave hyena, did live in Europe for around a million years, but at about twenty thousand years ago, their range was forced south.

It's not exactly known why they had to abandon Europe.

It may have been due to the colder climate or having to compete with humans for resources.

It could have been a combination of these factors.

Right, it got colder, harder to get food, but then they also had to compete.

There's no definitive theory on this that has been sort of I mean, it's really hard.

It's really hard to prove anything that happened in the past.

But the understanding of why hyenas had to leave Europe is not super well understood.

There's just some theories that lack a whole lot of evidence.

So they did exist in Europe though, for sure, and they did exist in cold climates before they were forced to leave, And we don't know whether they were forced to leave because say, their coats were insufficient or something like that.

So onto the winter coat claim.

So I looked and do this.

I saw tons of posts about this on various social media websites, and like you, none of them I could find any reliable sources, Like it would just be this claim like did you know that hyenas grow winter coats because they used to live in Europe?

And variations of that all over.

Very frustrating, right, like, you know, how do you determine whether this is true?

And I looked on Google scholar which is sort of my go to resources in terms of really trying to find some kind of evidence of something.

I couldn't actually find any really good sort of studies on this.

The closest things I found were like kind of vague claims made by books written I don't know, like in the nineteen thirties or something, right, So not really I wouldn't consider that a reliable source, so I'm not going to use that as one.

But I kind of dug into the posts themselves, these social media posts, and interestingly, I found that they depict different species of hyenas, So some of these posts depict like a brown hyena, And if you a brown hyena is going to be different than a spotted hyena.

They actually have a longer, shaggier coat than a spotted hyena.

But they have this coat year round and they're they're they're very they're very cute, they look very nice.

But it's like basically claiming that this is a spotted hyena, right, because spotted hyenas are the ones that used to be in Europe, and then showing a brown hyena.

So I think part of that is that it's subverting the expectations of the person, right, like, who may not know the brown hyena exists because they're only expecting the lion King's sort of hyenas with the really short coats and not the brown hyena, which has a longer coat.

So yeah, brown hyenas are a different species.

They have thicker coat year round.

They live in Africa.

Their coat could be used for thermal regulation or protection, but it's not really meant for cold winter seasons.

But including the post that the listener sent me, there are posts that genuinely depict spotted hyenas with shaggy coats and the images of actual spotted hyenas In these posts, to me, actually do show a normal variation in coat and main and not necessarily one that is seasonal.

So one source of the confusion could be that spotted hyena fur length changes as they age, So from seven to fifteen months old they have longer fur, which then gets a bit shorter as they're older, and then really old hyenas might have some hair loss that gives them a much shorter coat.

Can also depend on the health of the hyena.

If the hyenas more malnourished, it's not going to be able to find off mites and parasites as well, so then it might have more mange or more hair loss, more itchiness, so then it'll have a thinner coat.

And so there are a lot of factors that can affect coat length and hyenas.

I really couldn't find any evidence any indication of their coat length changing seasonally with colder weather or being triggered somehow to grow out, say if they're at a zoo where there's colder weather than they would encounter in their natural habitat.

Really couldn't find any evidence of that.

That doesn't mean it couldn't be true, right, Like, there could certainly be some effect that temperature has on their shedding, right, I think it's completely plausible that if it's cold, somehow the hyena's hair follical growth cycle could be affected by that, right, very believable, But couldn't find any studies on it, couldn't find any evidence.

But I did find plenty of evidence that there are lots of variations in hyena coat length as well as the patterns on it that does not have to do with temperature, So that could be basically, these these posts, like these images could just be say a younger hyena at a zoo where there's snow around and someone took a picture, and that are making this claim that in general hyenas grow out these longer coats in the winter without any evidence of this being true.

So I'm not going to say it's not true, because again I think there's a it's a plausible hypothesis that hyenas could grow out their coats in the winter, but I couldn't find any evidence of it, And so when there's no evidence, I think it's not responsible to make the claim that this is something that is happening, right, especially knowing that you can have a law kind of a long haired spotted hyaena uh in perfectly warm weather like that.

If you if you look at like go online right like, if you're curious and look at images of spotted hyaenas, you will see uh pictures of them in Africa in what's probably perfectly warm weather, with a variety of coat lengths, short, longer.

And I would suspect that a lot of that has to do with age and health things like that.

Yeah, but no evidence.

It's it's temperature based.

There could be some effect, but yeah, we don't know.

And this claim that they have this sort of latent gene or capability to do it because they used to be in Europe, yeah, I really could.

I couldn't find I could not find evidence of that, so you know, still could still could be true, but you can't can't make a claim unless you actually have evidence of that.

So it's you know, social media is frustrating in that way, really spreading like something that it could be misinformation, and it's I think what's frustrating about it is there are plenty of really cool facts about hyenas and other animals that have plenty of evidence supporting it.

And if this is true, and somehow the first person who posted it had some access to a study that was done on this, and then that got lost in a mix.

That's also really frustrating because I can't using my modest research skills, I'm unable to track it down.

The listener, who I'm sure also has research skills, couldn't track it down.

So then you lose that like if it ever existed.

You lose that connection to actual research, which is especially important with like social media posts, because there might be some real research and then you look into it, maybe the details are a little different right from what the social media claim is.

And yeah, I mean things are just gonna get worse and worse with AI.

I've seen a lot of posts of animals that are making some claim about an animal and it's not even a it's not even a real image of the animal, guys.

It's like it's AI and it's you know, my There's like this video of a koala quote unquote adopting kittens and picking them up, and I was looking at it and my immediate feeling was this is not real.

Just there is something about it that felt a little uncandy, even though it was very photorealistic and indeed it's a I.

And then when you really looked at it, you could see that the number of toes and the placement of the toes on the koala is all wrong.

So yeah, there's gonna be a lot of these claims made online about things, so please do, like, I really do like to try to either debunk or bunk these things.

I don't know if bunk is the opposite of dbunk, but yeah, like, uh, send me if you find something online on social media where it's like making some claim about animals or even like an image of an animal that you're like, is this real or not?

Do feel free to send that to me.

You can write to me at Creature Future Pod at gmail dot com and I'll help you figure that out.

Because I think it's increasingly difficult to parse media landscape.

It's important to be able to do that, and it's it's getting it's getting harder.

It's getting a lot tougher to uh identify misinformation.

And so if it's something that's like outside of my area of expertise, I'm not very good at it because like the like AI and stuff is getting really good at faking faking you out.

So yeah, thank you so much for that question.

All right, on to another listener question.

I watched a video recently about human persistence hunting and the video said the hunt took eight hours.

This make me think, first, are there other persistent hunters in the wild?

And then what is the longest an animal will take to do a single task?

For clarification on what I mean, what is the longest amount of time a spider will take to build a web and doesn't take breaks while building its web?

What about burrowing animals?

How long will they take to build their home?

What about mating displays?

What is the longest an animal continues its dance or display before it will stop?

Or are there animals that will dance to their deaths?

Thank you for the wonderful podcast and for helping me understand evolution a little better, which is to say, now understand evolution less than I thought, but more than I did.

But that's science.

And this is from Daniel Hi.

Daniel, Yeah, I mean, I think when you start learning stuff, you realize how much you don't understand.

So getting more confused is actually sometimes assign your understanding things better.

And I'm certainly confused a lot of the time.

So you are right in that humans are thought to have hunted not by necessarily being the fastest or the strongest, but by being able to out endure or outsmart their prey, so distance running, tiring out the prey, but also hunting together and using strategy.

We have a pretty unique ability for patients long term or medium term planning.

That doesn't mean that we are the only ones, though, So let me I would actually just like to eat with your examples.

Just answer all the questions in your examples.

So the spider web question of like how long you could a spider take to build a web, it's a really interesting one.

We can both look at individual spiders who build a web on their own and social spiders who There are various species of social spiders who usually are these little tidy spiders who live in these big communal webs.

And so first let's look at individual spiders.

A spider who will build her web all on her own.

Many species of spiders can complete a web in around an hour.

Kind of depends on how big it is, how complex it is, so anywhere from like twenty minutes to an hour.

It certainly takes some patience, especially because there might be some interference and they have to start over again.

But for a real marathon weaver.

We can take a look at the Darwin's bark spider.

These are little spiders.

They're less than an inch and diameter, cute little fluffy spiders if you are into that sort of thing.

They're found in Madagascar and they make these giant webs all on their own, so like where the basic the baseline structure of the web can be up to twenty five meters or eighty feet long and then two meters wide, so they have what's basically like a giant bridge made out of web, and then kind of in the center of it, you have this large expanse where it is an actual like spider web with the spiral and the reticulated structure, and that one is about two meters wide, which is still quite big.

So the spider will sit on a tree branch and spray out a line of silk and let the wind carry it off to another tree.

They like to do this sort of at river banks where there's like trees on one side and the other side of the river and you have a lot of insect activity.

So the silk is really strong for it's a diameter, but it's also really really light, so it might carry it across the river, and then the wind takes it, and then it settles on another tree and wants the spider sense is that it basically has this long line, like I said, up to like twenty five meters, and now it can use that as a bridge for building the central web.

So it goes out.

It reinforces first this like sort of tether this line running between the trees, and then she starts to build the center of the web.

And yeah, it takes a really long time.

I wasn't able to find the exact amount of time that it takes, but many hours, many many hours to build this.

And she is really really patient because often she has to restart if some bigger animal messes up the web, or even if another another spider, either her own species a Darwin spark spider or some other orb weaver spider finds the structure that she's building and tries to sort of steal her foundation to build its own web, and so she'll have to like fight off this other spider or cut off the webbing herself, and so she has to restart and tear it all down.

She'll actually collect the webbing the silk, bundle it up and then she'll eat it because that's valuable for resources that she can't like redeploy the webbing, but she can eat it get some calories so that she can produce more of the silk from her spinneret, which is an organ on her abdomen.

They create a huge amount of this silk.

And it's not one hundred percent understood exactly how these little spiders are capable of producing just so much webbing to make these big, big webs.

But they must have a very efficient metabolism, and as their behavior suggests in eating webbing that they have to recycle, they must be very very good in terms of allocating their resources so they can produce a good amount of silk.

So, in terms of social spiders, this is like a different species of spiders, the little ones that live in these big, big communal groups.

There's many different species of these, and because they work in large groups, these they're more human like in their ability to create structures that take multiple generations to finish, sort of like humans building a cathedral, right, So they create these multi generational webs that take long beyond a spider's single lifetime to build.

And so recently there was actually a social spider web found that's over one hundred square meters found in a cave between Albania and Greece, made by over one hundred thousand tiny spiders.

And this has probably taken many, many, many, many many many generations of these spiders years and years to build this up.

I don't think they know yet.

This is a relatively recent discovery.

They don't know yet how old it is.

I would not be surprised if it was, you know, over one hundred years old.

And when it comes to burrows, we can actually turn to another arthropod.

So termites definitely when the prize, when it comes to patients and building burrows.

They build these giant tunnel systems that can sometimes be built over thousands or tens of thousands of years.

So these are termites building tunnel systems and termite mounds, which the mounds are basically like the dirt that they have to extract from the ground in order to excavate these massive tunnel systems.

And so they may have built started these structures tens of thousands of years ago and are still being inhabited by living termite colonies to this day.

In Brazil, there is a termite colony estimated to be around four thousand years old.

It is the size of Great Britain.

So in it's this large area with two hundred million termite mounds, which you know they're not always like big mounds, but you know there is it is, there is a mound there of some of this dirt that has been excavated and put above ground.

It is.

I didn't really when I saw these these numbers, I was like, no, this is it has to be misinformation.

I looked into it, and it seems to be genuine that it is just genuinely a termite country.

That it is that these termines have over thousands of years built up in this Brazilian Uh, these Brazilians plane planes area.

So the termites created what's essentially like an entire England size termite civilization.

Yeah, let's let's keep going on with these really patient animals.

The question asker really did identify an area in which animals have to be typically quite patient, and that is courtship rituals.

That's usually an exercise and endurance and patients which might help the female select a male who has the fortitude UH to provide good genes.

For example, for a lot of species that do co parenting, the assessment is often like, hey, can this other this this mate like actually have the attention span, the devotion and to be able to take care of our offspring together.

So let's talk about some of the interesting mating rituals that take a long time.

So, the greater mouse eared bat, which is the largest native bat in Europe, compete for females in les so alek is a mating display arena.

It's a word used for multiple in any kind of species that uses like this, like basically a big mating area grounds and competes for female's attentions there.

So these mouse eared bats will find a bit of roosting territory and they will defend it from other males and let out these trill vocalizations to attract the females.

So all of this is tiring enough, but once a female actually comes and chooses him, mating can last over thirty hours.

That's three zero thirty hours of mating.

So this doesn't mean they're kind of constantly having sex during this time.

A lot of it is cuddling actually, so the male will wrap his wings around the female for hours after copulation before going at it again.

It's very, very time consuming to do this, very romantic, and it also helps him reaffirm the bond with the female, so the female is motivated to stay and also to keep fend away other males who may try to get in on this mating.

So who knows, maybe human cuddling has you know, there may have been some point at which human cuddling had a similar purpose.

Right, So, in terms of your other question, are there any mating rituals where the animal just basely does courtship until they die.

It's not exactly courtship, but there is an animal that mates to its death, so this is the antikiness.

These are small mouse like marsupials in Australia who go on frantic mating sprees until the male dies of stress.

So for two to three weeks they mate near constantly, sometimes a single copulation lasting over ten hours, which is yeah, there's a lot.

The huge surges of cortisol and testosterone actually kills off their organs and they die and the females will mourn them by eating their corpses, which is fuel for the offspring that the males worked so hard to fertilize.

So you know, your basic meat cute in nature.

Well, guys, thank you so much for the question.

If you've got some for me that you want me to answer on the air or in a response to your email, you can write to me at Creature feature Pod at gmail dot com.

That's Creature feature Pod at gmail dot com.

Thank you, guys so much for listening, and thanks to the space Cosaics for their super duper awesome song XO Lumina.

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I don't judge you, I'm not your mother, but man, you know make maybe take some breaks when you're doing a mating marathon.

Maybe get a massage or do some light meditation.

Don't be like the anti Guayanas.

All right, see you next Wednesday.