Petting Zoo: Show and Tell
Our panel brought in some interesting items into the studio. Joining Chris Smith is Vet Stuart Eves from cambridge university, Jacob Dunn from Anglia Ruskin to talk about primates, Reptile expert Jason Head from the Zoology Department at Cambridge University and Eleanor Drinkwater from York University for everyone's insect enquiries.
Stuart - Okay. Well I have to say at this point that your producer took me down from the original plan which was to bring in what is called a Sulcata tortoise which is about two stone of very angry shell. So what I'm going to do is: I'm just going to dive down into the box now and we have two red-foot tortoises which are kind of pets of ours from home. We have a whole range of tortoises and I thought it'd be a fun thing.
Chris - Because that’s a shell of a show and tell! Oh my goodness, that's enormous.
Stuart - Yeah what I've got in my hand is, she's probably about 25-30 centimetres long. This is this is Tina who's one of our red-foots. So she's quite a dark colored tortoise but then, actually, the really striking thing about her is on her front legs she has these really bright cherry-red scales, really.
Chris - How do they grow?
Stuart - In terms of with the shell?
Chris - Yeah.
Stuart - So very much like trees or very much like nails, if you like, they effectively add an extra kind of layer where the two plates come into contact with one another.
Chris - So the bumpy bits on the outside...
Stuart - Yeah
Chris - That's - each of those is a plate?
Stuart - Effectively it's a plate, there would just be multiple ones of them.
Chris - So it’s made of keratin is it? The same stuff as my fingernail?
Stuart - It's very similar to bone, and certainly the ones along the top will actually be fused with her backbone, her vertebrae. So the shell and and their actual kind of skeleton is one thing, but yes.
Chris - They're depositing a new layer almost like nail growth all the way around each of those sort of square plates? And so the whole shell grows...
Stuart - … like tree rings. Yeah, just adding and adding, I guess just because there is a junction.
Chris - Jacob?
Jacob - I just had a question because at moment my daughter Lily is looking for her next pet, she’s a budding animal rescuer. How cat-proof are tortoises?
Stuart - Ahm… there's also the question of how tortoise-proof is the cat... It's difficult, it would depend on the individuals. These things, they do have very good defences. They'll put their head in, they'll bring their front feet up to protect themselves. They are very good pets, all I would always say is: do a bit of research on how they live, because these are highly specialised animals.
Eleanor - Talking of being a good pet, is it actually pooing right now?
Stuart - Errr, there’s a possibility. Yeah.
Chris - Moving swiftly on. Rather like the tortoise. Or not! What about their hibernation, though? Because these animals do hibernate don't they? Because they would normally have a long sleep - because my mum used to have a couple of tortoises when I was very little and we used to put them in a box in the shed for the wintertime and they would go to sleep. So what is their normal life cycle?
Stuart - Sure. One thing to say, some tortoises will hibernate and others don't. So Tina who I've got in my hand and then Solomon who's her boyfriend who's still in the box. They are not the type of tortoise that would hibernate and it goes back to really where they're from. If they're from the tropics there would be no real change in season, there's no real kind of need. They might actually do the opposite and they might aestivate and actually kind of see their way through the summer and warmer times by hiding. How it's done? Well some people put them in the fridge
Chris - And it initiates the process?
Stuart - Yeah, well, the slow drop in temperature - you need to take them down to 5 to 8 degrees. I do need to qualify that by saying just just any fridge. They do need ventilation and other things, but yes, it's not uncommon. I've known friends where you go round their house, you open up the fridge in the garage and what is in there? It is a whole load of tortoises!
Chris - And they’re not for dinner? We should emphasise they’re not for cooking!
Stuart - I have been assured they're not.
Chris - Goodness me. Stuart, thank you very much for bringing in Tina and Solomon, it's very nice to meet them. Hopefully they're not going to destroy the studio any more while they're with us now. Now Jacob, at the other end of the spectrum you've put down a pot of rather sinister looking something, next to my chocolate biscuit which is making me quite alarmed. What's in that pot?
Jacob - Well I brought sort of two related things for show and tell here. One is from one end and one is from the other end. So I'll start with the top end. This is a Howler monkey skull. These are what I study, which are primates from Latin America, all the way from Mexico down to Argentina. And they make these incredible noises and the reason they can make these incredible noises is because they've got this big, big bone which all vertebrates have but in Howler monkeys it's sort of expanded into this huge sort of cup-shaped chamber and it's just this most incredible feature of the Howler monkey.
Chris - Because in us that is a little strip, it is thinner than a finger, the sort of crush in the middle of your neck. If you were going to, sort of, cut someone's throat, that's roughly where the hyoid bone is, isn't it?
Jacob - Exactly.
Chris - It's just there to stabilise the muscles in the neck. But that's huge and it’s an enormous thing!
Jacob - In all primates it's in the same place, but Howler monkeys have developed this trick to expand it and they've got this really adapted hyoid bone that's sort of this big sort of balloon.
Chris - And that's how they make the sound they make?
Jacob - They do this inhale and exhale. And they go [fierce Howler monkey impression]
Chris - That's very good! You can see that you spent some time with them…
All - [laughter]
Jacob - I have spent a lot of time with Howler monkeys!
Chris - Because they’ve learned how to copy you!
Jacob - And when spending time with the Howler monkeys, most of the time that I've spent in the jungle, which was about five years in total I guess, I was collecting stuff from the other end. So what I've got in this other tube here is some Howler monkey poo.
Chris - Yeah.
Jacob - And there's a good reason why poo is a really wonderful resource for biologists. You can sequence DNA from poo, you can work out what they've been eating, both from the sort of seeds and things you find in there as well as sequencing the DNA of any bugs or fruit or anything. You can also look at what bacteria are in there. So you can actually learn an incredible amount from collecting poo without having to be invasive. You don't have to capture the animal or anything.
Chris - So there’s no stress for the animals, you just go and you can follow because you can identify the DNA of the individual that made the poo, in the poo. You can track individuals and see how their life is changing and how seasons and other factors are affecting them.
Jacob - Absolutely.
Chris - Cool.Thank you, Jacob very much. Now, Jason, you are holding your mobile phone, are you going to do something with that?
Jason - Yeah. So, because I work with fossils I don't have the capacity to bring them in but because we're talking about kind of large bodied reptiles and things like that on this trip, what I have actually, is a clip on my phone. It's a video clip that I took two summers ago when I had the opportunity to go to Rinca Island in Komodo National Park in Indonesia. And so I'm just going to pass this over and you can hit play and let us know what you’re seeing.
Chris - So he’s giving the phone to Eleanor.
Eleanor - Oh! There's an adorable komodo dragon, which is kind of wandering over.
Chris - So when you say adorable, how big, relative to Jason?
Eleanor - Erm… I don't know. Maybe… How big would you say that was?
Jason - That one was two meters long.
Eleanor - Oh, it's really cute!
Chris - And is it after him?
Eleanor - Well it’s kind of walking towards him and it’s kind of going a little bit faster. He just wants to say hello!
Jason - We were in the forest on Rinca Island and the dragons are very habitat-specific in the national park area. So the dragons are born in these little valleys and they’ll actually live their whole lives in the valleys, but when you have a lot of tourism moving through, and tourism is starting to become a problem for the National Park, the dragons will move around a little more. And this one was just kind of coming up very quietly to, I'm sure, say hello and not bite my achilles tendon or anything like that… But fortunately I was with some dragon biologists who were quite adept at using large sticks to...
Chris - Just fend it off?
Jason - ...prod the dragon off, yes.
Jacob - Don’t they have some really nasty stuff in their saliva that would do you damage if they were to bite you?
Jason - Yeah. There's been a whole history of study and conjecture about Komodo dragon saliva, that for many years it was thought that they had this kind of toxic bite, a septic bite, because it was thought that they would collect rotting meat in the serrations in their teeth and that would generate all these toxic bacteria. Because we know that dragons will bite water buffalo and the water buffalo will die of sepsis or die of an infection in the wound usually weeks later and the dragons will kind of follow them around for weeks until they keel over and they'll eat them. More recent studies have shown that there actually are some specialised enzymes in their saliva that basically lower blood pressure and are also anticoagulants, so they keep the wound open. They're not toxic venoms in the way that a cobra rattlesnake would have them, but they do definitely facilitate keeping the wound open. And probably what is happening is that animals at the dragons bite are mostly standing in puddles of bird faeces, so that's how they get the sepsis. So I think that these are strategies for the dragons to be able to eat the food items.
Chris - They're amazing creatures aren't they? Because they can also start a new colony of dragons from just one female dragon, because genetically, they can undergo parthenogenesis and the next generation in an egg, if it's not fertilized, actually ends up being male by default. So if you've got just a female washed up on a remote shore or something, the egg she lays will by definition turn into a male. So you can then start a new sort of sexual reproductive cycle with them. They're amazing creatures.
Jason - Yeah. And I think that was discovered at the Chester Zoo when they had one female who had never mated and gave birth to viable eggs.
Chris - Yeah, in 2005-2006 they actually published that as a paper in Nature. I remember reading about it. Eleanor, you’ve got a packet in there. It's not as thrilling as a pot of poo. But what's in your little packet?
Eleanor - I say it's just as thrilling as a pot of poo, if not even better, because it's to do with invertebrates. So this is actually a tag which we had custom made to track Titan beetles in the French garden rainforest.
Chris - Can I have a look?
Eleanor - Yeah sure.
Chris - To describe this for people there is a little ball. It's about the size of my little fingernail and sticking out of it is this long thin hair-like projection. It's about the size of a hair, actually, but it's a little aerial, like a little antenna. Is that a tag?
Eleanor - Yep, that’s a tag.
Chris - For what?
Eleanor - So that's for a Titan beetle. So, Titan beetles…
Chris - You glue that on a beetle?
Eleanor - Yeah well, we were trying to understand the movement of this particular beetle, It's the biggest beetle in the world and no one knows anything about its behaviour.
Chris - How big is big?
Eleanor - So biggest it gets to its 16.7 centimetres. So the biggest one we found was 15 centimetres. And, you know, you can pretty much have a wrestling match with this creature.
Chris - That’s big!
Eleanor - Yeah! And occasionally that a break out of their tanks and trash our kitchen. They are very, very destructive little creatures. So yeah.
Chris - What have you learnt?
Eleanor - The reason why we're interested in them is that they’re highly trafficked as a species, they're very very valuable. We get collectors who pay a lot of money to have dead specimens of this animal. And unfortunately a lot of our specimens are actually recaptured by local hunters in the area.
Chris - So you don't get any data?
Eleanor - We did get some data, but it was very unfortunate whenever we would track our data and then we'd track it to a person and then he'd be like: “Oh is this yours?” and you’d be, like: “Yes, this is mine.”
Chris - So in that gadget is there a little power supply that then beams a signal out that you can track?
Eleanor - Yes.
Chris - How long does it last for?
Eleanor - They last about two or three weeks and they've pretty good range on them, particularly, you know, considering that we're working a very, very dense dense rainforest.
Chris - And how far do these beetles move, though? Because they're big - you're saying 15 centimetres across. What's their range?
Eleanor - Yeah. So they're really interesting. Most of the time they don't do anything. They kind of sit around and we track them over a while, and we just found that they moved less than a metre. And then, on Sundays - we didn't manage to track this, but according to anecdotal reports from local entomologists - they climb up trees and then they use the height of the tree, essentially, to kind of parachute down, and apparently they reckon that they can go kilometres like this which is just... I’d love to see it!.
Chris - How much do they weigh?
Eleanor - They weigh a lot, maybe 30 grams the biggest one.
Chris - Okay. But even so... I'm just thinking, it's like a cricket ball coming at you, or a football actually, isn't it? Coming at you from the sky.
Eleanor - You have to be careful as well. You know, they’ve got these incredible mandibles that can actually bite to the bone. So if it gets your finger, it's a quick trip to the hospital.
Chris - Amazing stuff you get up to, Eleanor. Thank you very much