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The SciShow Talk Show has a new look! And a new guest who isn't new at all - Jessi Knudsen CastaƱeda from Animal Wonders joins Hank to talk about one of her favorite subjects: poop! They are joined by Augusto CastaƱeda and Yucca the red-footed tortoise for a visit.

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HANK: Hello, and welcome to Scishow Talk Show, where today we're in our brand new location, which is pretty sweet.  And also, we have with us, Jessi from Animal Wonders, who is our special guest today.


HANK: So, usually how we do things is, we start out by you trying to stump me.


HANK: With a question that I don't know the answer to.

JESSI: Alright, this is fun.  Um, hmm.  How about, do you know the three different parts of bird poop?  You know, when they poop on your windshield, and it's...

HANK: Well I can identify, by sight, two of them.

JESSI: Okay.

HANK: 'Cause there's the white and there's the brown.

JESSI: Mm hm.

HANK: So I'm gonna guess that the brown is the poop part of the poop.  Does that count?

JESSI: The poop part of the poop?

HANK: Did I completely get it wrong already?

JESSI: The poop part of the poop, I guess you could say that, yeah.

HANK: It's feces?

JESSI: Yeah, yeah.

HANK: Okay.  Um, and then I'm pretty sure- like, 'cause birds don't pee.  There's a southern saying, um, when you're good at keeping secrets, you're like a bird, because water comes in and it never comes out.

JESSI: Okay.

HANK: Though, I'm sure that the water does come out, so is there a-a urea component?

JESSI: Yes, there is, kind of.

HANK: So they don't produce pee they same way we do.

JESSI: It's not urea.

HANK: Okay.  Is it uric acid?  Is it some ammonia-based compound?


HANK: And then is there just water? No?  I don't know the third, the third I'm totally stumped on.

JESSI: Do you know the color of the third?

HANK: Uh, well there's the white-


HANK: So the white isn't the uric compound.

JESSI: It is.

HANK: It is.

JESSI: It is.

HANK: Okay, so there's another color in there?

JESSI: Yeah.

HANK: Oh I've missed it.  I haven't paid enough attention to my bird poop.

JESSI: Well, um, if you consider clear a color.

HANK: Oh, okay.

JESSI: So you have brown, then you have the white, then you have the clear.  So you got the brown!  Good job, that was the feces.  And you've said the name of the other one.

HANK: I have?

JESSI: You've said the name of the white one.

HANK: Uric acid.


HANK: Okay.

JESSI: Good job.   Alright, so the third one, do you wanna know?

HANK: Yeah.  I'm not gonna get there.

JESSI: It's actually, they call it ur-ine.

HANK: Urine.

JESSI: Yeah, so it's urea.

HANK: So, yeah.  But it's just like, it's like our urine in that it's composed of a bunch of different stuff.

JESSI: Yeah, and then the uric acid is going to be really high in, uh, really high in acid, and it's gonna be chalky when it dries.  Chalky white.  And it's really insoluble, that's why.

HANK: Yeah.

JESSI: That's the stuff that's really gonna mess up your car, if they do poop on your car.

HANK: So that's interesting to me, I wanna know more about the chemistry of this.  Because I wanna know if, if you can actually pack more ammonia-which is one of the things that our kidneys do, it spits up, basically, used up proteins.  So I wonder if you can pack more of those ammonia compounds into a smaller area by making them those insoluble uric acid compounds.

JESSI: They have really efficient kidneys, and that's how they make that.  And there are some birds that only poop uric acid.

HANK: Wait, no feces?

JESSI: No feces.

HANK: What?  What do they eat?

JESSI: Um, a lot of them are gonna eat mostly fish, 'cause they're really easy to digest and get all the nutrients out of them.

HANK: But they eat whole fish.  Where do the bones go?

JESSI: Some of them are really really good at digesting bones, and some of them do something else.  So think of an owl or a hawk...

HANK: Right, it comes back up, the other way.

JESSI: Yes.  In the form of...

HANK: Pellets.

JESSI: Pellets, exactly.  So that's where they're going to get rid of most of there insoluble stuff, the really hard to digest stuff.

HANK: So, that was fascinating.  Are we just gonna talk about poop all day?

JESSI: Yeah, I would like to talk about poop all day.

HANK: That sounds like a great- do we have a poop specific guest today?

JESSI: Um, we do have a poop specific guest. Do you want to meet that guest now?  Or do you want to...

HANK: Talk more about poop first.

JESSI: Do you wanna see some more poop.

HANK: Oh you, you brought-

JESSI: I brought some poop guests.

HANK: So poop, poop is the guest.

JESSI: Sure.

HANK: Okay, let's, let's first meet some poop.

JESSI: Alright, alright.

HANK: What did you bring for me?


JESSI: Um, I wanted to set it up here.  Alright I want you to guess...

HANK: You should've first made me guess if this is poop...

JESSI: Oh, that's true.

HANK: ...because it doesn't even look like poop to me.

JESSI: Uh, let's put that on right there.  Well this is poop, and some dirt.

HANK: Okay, so, poop would b the brown little ball parts.


HANK: That's, very dry... looking poop.  Is it desiccated?

JESSI: Some of it's older.

HANK: Or is it old.

JESSI: Some of it's newer.

HANK: Okay.  Are you going to try to have me guess who made this poop?

JESSI: Do you want to?

HANK: Yeah.

JESSI: Go ahead.

HANK: It's a small... mammal.


HANK: I was wrong.

JESSI: It's small, it's small.

HANK: Is it a repti- no.   I have no idea.

JESSI: It lives in the dirt.  And it's going to eat decaying matter.

HANK: Oh is... what?

JESSI: Well it is a detrivore.  It's a decomposer.

HANK: Is it insect poop?

JESSI: Yeah.

HANK: It's extremely-

JESSI: It's not insect, it's a millipede.

HANK: Oh, millipedes aren't insects.   What are they?  Bugs.

JESSI: Okay.

HANK: They're bugs.

JESSI: Okay.

HANK: Bugs is actually a technical term.  I learned that.

JESSI: It is, there are certain-

HANK: If you want to include non insect insect-like things, you should say bug.  We'll put what a millipede is on the screen. (Arthropod)

JESSI: Sounds great.  A millipede is a bug.

HANK: So I would not have assumed that a bug could make poops that big.

JESSI: Yeah, it comes right out the back end, it opens up a little bit, and a little round little thing comes right out.  And then...

HANK: You've watched this happen.

JESSI: I've watched it, it's one of the things I do in my pastime, watch animals poop. 

[both laugh]

JESSI: Um, so yeah.  So then it becomes basically like fertilizer, it makes the nutrients available for plants, to use.  Ready for the next one?

HANK: That's pretty cool poop.


HANK: Just make sure you... collect all the poop.

JESSI: One down.

HANK: That just looks like food.

JESSI: That looks like food?

HANK: Well, like, like rabbit food.

JESSI: Maybe that you like to eat.

HANK: It doesn't look like human- it looks like, if you had a bag full of that, at Animal Wonders, I would think that it was rabbit food.

JESSI: Hmm, well you know what, this poop is actually edible.  Not to- I wouldn't eat it.  I would not suggest you eat it either.  But the animal that makes this poop would actually eat it.  It's called coprophagia.

HANK: Okay, so is th- I've heard that like rabbits, will poop, two different kinds of poop.


HANK: They will poop the first poop, and they will eat that, and they will produce a second kind of poop.

JESSI: Yeah, and that first poop, it's like sticky, and it kind of clumps together, it's high in vitamin B.  And it has a lot of other goodies in there that are gonna help their gut work better.  So this is not rabbit poop.

HANK: Is it lagomorph poop at all?

JESSI: It's not lagomorph poop, it's rodent poop.

HANK: Is it chinchilla poop?

JESSI: Oh, very close.

HANK: Okay.

JESSI: It is patagonian cavi poop.

HANK:It's cav- I wasn't going to get the cavi.  I wasn't going to get there.

JESSI: Cavi, cavi poop.  There's a couple animals in the cavi family, like, uh, capybaras, and then the patagonian cavi-

HANK: I feel like capybaras would have much bigger poop.

JESSI: Yeah, it would be, it would be.

HANK: Are they the largest rodent, capybaras?

JESSI: They are the very largest rodent in the entire world.  Alright, you ready for the next?

HANK: More poop!

JESSI: More poop.


JESSI: That is fresh from this morning.
HANK: Yeah, it's super fresh.  It looks like slugs, it looks like you brought me animals.

JESSI: It's gross, I wouldn't touch that.

HANK: No, I'm not planning on it.  I haven't touched any of the poop so far.

JESSI: That's true.

HANK: You may have noticed.  I... yeah, I have no idea.

JESSI: So this animal's gonna live in the trees, and he's gonna live in Madagascar, and it's a chameleon.

HANK: This is chameleon poop.

JESSI: It's chameleon poop.  There's a little bit of the uric acid right there, you can't really see it very well.

HANK: The little white thing.

JESSI: Yeah, the little white dot there.  This is mostly digested cricket, right here.  So, the uric acid is going to be in a later deposit.

HANK: Oh, it's just separated out.  It all comes from the same hole, but you never know.

JESSI: It does, do you know the hole's name?

HANK: The cloaca.

JESSI: Good job, yes.

HANK: I love the cloaca. I love the idea of the cloaca.  I don't love- I just, I'm fascinated by the idea that we have all of these extra holes, and these other animals are like, psshh.

JESSI: Yeah, make it easy.  Just one.  Alright, did you learn about poop today?

HANK: I sure did learn about poop today, that was amazing.  Now, it is time for us to be joined by a, uh, guest of some kind.  I don't know if it's going to be fuzzy or scaly or...

JESSI: It's gonna have something to do with poop!

HANK: It will poop.

JESSI: It might poop. 


HANK: We have a turtle on our table!  Well, it's probably not even a turtle, is it?  It's a tortoise.

JESSI: You're right.

HANK: Ah,I'm just glad I caught myself.

JESSI: Nice work, nice work.

HANK: So, we've also been joined by Augusto, who has brought the tortoise.  Augusto is your business partner, and, uh, life partner.

JESSI: That's right, that's right.  Partner in everything.

HANK: So tell me about this, what is this thing that we have acquired?

AUGUSTO: This is, uh, Yucca, our red-footed tortoise.  And, yeah, she's five years old now.

HANK: So, where is Yucca from?

AUGUSTO: She's from the rain forest, South America.

HANK: That's a large area to be from.

AUGUSTO: It is, it's pretty huge.  As it rains a lot, it gets muddy down there, and so she'll walk around on her tippy-toes, not to sink in.  And, uh, she'll have fun around there, looking for all kinds of little grubs, insects, and uh, also fruit that comes falling down from those trees out there. 
And she eats the whole entire thing, including the seeds.  And when the seeds pass through her body, they germinate, and when she poops them out, they basically will grow  hit the ground, and basically turn into new fruit trees.

HANK: So you're basically helping spread fruit trees so that- basically you're an agriculturist.

AUGUSTO: That's right.

HANK: Creating more fruit trees, so that you can eat more fruit.  Clever.

JESSI: Yeah, we call her the gardener of the rainforest.

AUGUSTO: And uh, she's gonna get a lot bigger than this size.  Usually about-

HANK:You're already pretty big, man.

AUGUSTO: Probably up to maybe 16 inches or so, and they can weigh up to 40 pounds.  Yeah, depending on, male or female.  And uh, she's only five right now, like I said earlier, and she's gonna live to be, about 80 years old.

HANK: Wow.

AUGUSTO: Yeah, they have a long lifespan.

HANK: That's- so you're gonna outlive all of us.

JESSI: Probably.

HANK: Wow, congrats.  That's exciting for you.  Um, who's- wow.  That's crazy.  I've always been afraid about having animals that live longer than me, because who's going to take care of them when I'm gone?  But I'm sure you guys will figure it out.  Can I hold, you?


AUGUSTO: Do you know the-

HANK: You're pretty heavy already.

AUGUSTO: The names for the parts, the two parts of the shell?

HANK: No.  The top and the bottom.

AUGUSTO: Yeah, that's good.


JESSI: You might not wanna tip her like that, she tends to pee if you do that.

HANK: You like to be, you like to be flat. That makes sense.  It's uh, it's- turtles and tortoises are so amazing, that you create this thing around you.  And the, the pattern, it's like the rings on a tree.

JESSI: Now there is a myth that if you count those rings you can tell how many years old they are.  It's just a myth.

HANK: That's a lie.

JESSI: Yeah, it depends on- they grow more the more they eat.  So she's obviously well fed.

HANK: Good job.

AUGUSTO: And those are her scutes, every single one of those.

HANK: Is a scute.

AUGUSTO: Yeah, it's a scute.

HANK: And uh, you were telling me the name of the top and bottom of the shell.

AUGUSTO: That's right.  So the top part there is the carapace.

HANK: Okay.

AUGUSTO: And then the bottom is the plastron.

HANK: The plastron.

AUGUSTO: The plastron's a cool name. And um, together they make one cool-looking tortoise there.

HANK: Yeah.  {to tortoise} Where are you going?

JESSI: Checking things out.  You can tell if it's a  male or a female by actually looking at that plastron underneath there.  If it's flat or a little convex, then it's going to be a female.  And if it's concave, it's going to be a male.
And she doesn't like to be tipped very much but you can look under there.  Hers is pretty much flat.

HANK: Yeah.

JESSI: But it doesn't go in at all.

HANK: That is neat.

JESSI: So do you know why it would have to be convex, caved in- or concave, like that to be a male?

HANK: Um, so you get get on, um, a female.

JESSI: Yeah, and balance up there.  And then it has to be bigger for the female to lay the eggs.  Good job, nice.

HANK: I mean, turtle- tortoise sex, and also turtle sex, has to be a little bit complicated.

JESSI: Yeah, maybe uncomfortable or, tricky.

HANK: Tricky.  I wouldn't necessarily call It uncomfortable, but definitely tricky.

JESSI: Well she didn't do the thing that she's most famous for. She usually decides to poop all over the place during presentations.  But she did leave a big pile for us in her... car-seat, her carrying crate.

HANK: Yeah well I guess she finished... with her business on the way.

JESSI: Yeah, I wouldn't put that past her though, she's gonna poop again as we go home, but, um.  She's really good at that, and that's because she's a seed disperser and she's supposed to... digest things really fast. And so those seeds will get digested and they'll just land, right out.  Fertilized and everything.

HANK: Well what a beautiful, amazing animal.

JESSI: Thanks, Yucca.

HANK: Thanks.  Thank you, guys, for coming and helping us out with SciShow Talk Show today. It was fascinating.  Um, I just, I feel like we could talk about poop forever.

JESSI: Well it's and endl- I, still talk about poop and I've been doing this for years and years and it's a, it's a great dinner time conversation.

HANK: Absolutely, absolutely.  Thank you guys.

JESSI: Thank you for having us.

HANK: And thank you for watching SciShow Talk Show.  If you have any questions or ideas for us you can leave them in the comments, and if you wanna keep getting smarter with us here at SciShow, you can go to, and subscribe.