The Charismatic Kangaroo Relative That Might Remind You Of Your Dog

IRA FLATOW: This is Science Friday. I’m Ira Flatow. And now, it’s time for our Charismatic Creature Corner.

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[CAT MEOW]

Joining us again in our Charismatic Creature Corner is our correspondent, Science Friday’s own Elah Feder. Hi, Elah.

ELAH FEDER: Hi, Ira. Yes, I am back once again to plead the case that one very special creature is worthy of the coveted charismatic creature title. And by creature, again, I mean almost anything. We count tapeworms. We count bacteria. And by charismatic, I mean a creature that is as worthy of our curiosity and enchantment as a baby panda.

IRA FLATOW: Whoo, that’s a pretty high bar you’ve set.

ELAH FEDER: If you like baby pandas which, of course, we do. So last month, I made the case that slime molds are charismatic, because I wanted a bit of a challenge. I might have been in over my head. I did get some people on board. Some people are on the slime train. And they left some very nice messages on our VoxPop app. But we also got this.

KATE: This is Kate from Modesto, California. I’m pretty sure slime molds will never be charismatic in my opinion.

IRA FLATOW: You have something now better, then, for Kate?

ELAH FEDER: Well, funny you should ask. Kate had something better for Kate. Kate left us another message with this suggestion.

KATE: I’ve always been really interested in Tasmanian tigers. Many people say that they’re extinct, but some people report sightings. Do you have any information on them?

ELAH FEDER: OK, so since Kate is my toughest critic, I decided to give this a shot. First of all, these are not Tasmanian devils, which is what I thought Kate was referring to at first. Tasmanian devils are endangered carnivores that live on the island of Tasmania. We’re talking about Tasmanian tigers. Have you heard of these before?

IRA FLATOW: Yeah. Who hasn’t?

ELAH FEDER: Well, you’re very learned.

[LAUGHTER]

I had never heard of these before, but now I’m in deep. OK, so like Kate said, they’re considered officially to be extinct. But people have been reporting sightings, like hundreds of sightings not just in the island of Tasmania, but in mainland Australia, too.

IRA FLATOW: OK, for those of us who have confused Tasmanian devils with Tasmanian tigers, fill us in on what a Tasmanian tiger is.

ELAH FEDER: OK, so the Tasmanian tiger, also known as a thylacine– it actually looks a lot like a dog, but with like Tiger stripes, kind of on its back, except that it’s not a dog. It’s not a tiger. It’s actually a marsupial, like koalas and kangaroos. It actually has a pouch and everything.

IRA FLATOW: I noticed we have a photo up on our website at sciencefriday.com/cute.

ELAH FEDER: Yeah, not to bias you or anything.

[LAUGHTER]

So here’s the deal. The last known Tasmanian tiger died in a zoo in 1936, actually as a result of human neglect, it sounds like. 50 years later, the species was declared extinct, but people keep claiming to see them. And earlier this week, I caught up with one of those people– Neil Waters. He told me about a time 10 years ago when he was walking in Tasmania just before dark.

NEIL WATERS: And I’m walking up this dirt road through the bush. And I can hear this crunching of branches under feet, somewhere in the bush alongside me. I can’t see it, because the bush is so thick, but I can hear it. Every time I stop, it stops, so something is following me.

ELAH FEDER: Creepy, right?

IRA FLATOW: Oh, yeah.

ELAH FEDER: So eventually, the creature runs off. But before it does, Neil does catch a glimpse. And apparently, it looks kind of like a dog, but not a dog. It’s dark, so this is important. He does not see the telltale tiger stripes. And he’s not 100%. He’s not totally sure what he’s seen. But then he starts talking to people and he learns about all of these other sightings. And then he himself sees one again in 2014, so he’s completely hooked.

IRA FLATOW: He’s hooked. So if he’s a geek like me and you see something, you want to go out and prove that they’re really there.

ELAH FEDER: Exactly. So Neil is dedicating– he’s actually dedicating the next two years of his life to living in the bush and finding definitive proof that these animals are still out there. He walks around with night vision goggles. He goes looking for their scat. He’s even set up a bunch of motion sensitive cameras. And a lot of other people are going to help him sift through those photos, like a big citizen science project.

NEIL WATERS: Eventually, someone will probably get the irrefutable proof. And when that happens, we want scientists to get on board as much as possible and say– that’s why I keep annoying them and saying, hey, look, [INAUDIBLE].

[LAUGHTER]

SPEAKER: Are they annoyed?

NEIL WATERS: Oh, I’ve annoyed quite a few academics over the years, but I’ve got the respect of a few, too. So that’s OK. It’s 50/50 at most.

[LAUGHTER]

ELAH FEDER: So today, we’ve actually brought on another academic to annoy, to tell us more about the Tasmanian tigers and how you do research on an animal that is nowhere to be found. His name is Gregory Berns. He’s a professor of psychology at Emory University. Welcome to the show.

IRA FLATOW: Yeah. Welcome, Gregory.

GREGORY BERNS: Hi, Ira. Hi, Elah.

ELAH FEDER: Hey. So, Greg, first, Tasmanian tigers– they look like dogs, but are not dogs. What is up with that?

GREGORY BERNS: Yeah. So these creatures are fascinating. And as you said, the tigers are actually marsupials. And the only reason that we call them tigers is because they have stripes on their back. And when the original settlers of Tasmania saw them, and those would be the British colonialists, they saw them. And they saw the stripes. They said, oh, these must be some kind of tiger.

And that’s how they got their name. But they are not at all related to dogs. And I got interested in it, because of my interest in dogs and how dogs’ brains works. And I was interested to find out– what can we figure out about these animals? They look like dogs or coyotes, but they’re not. And so we started studying and looking for their brains.

ELAH FEDER: So this is a case of convergent evolution, right? How do you get two animals that are not remotely related, looking so much alike?

GREGORY BERNS: Yeah. And to really appreciate this, what this animal is or was, you have to go way back in history. We’re talking 200 million years at least. And to kind of give you an idea, this is the age of the dinosaurs. Mammals didn’t even exist back then.

And actually, the first mammals actually laid eggs. And the marsupials later descended from these creatures. And to give you an idea how long ago this was, this is when all the continents were jammed together. There’s just one big land mass– Gondwana, Pangea.

And as mammals evolved during this period of time, the continents started to separate. And what ended up happening was that these marsupials, these descendents from the very first mammals who actually laid eggs– they started to give birth live. I mean– but just barely, right?

The marsupials give birth live. But they’re tiny, tiny, little creatures. And they crawl into the pouch. And so these animals start evolving. And as the continents split up, the marsupials were kind of left to their own in what became Australia. And they had no competition from other animals, which were called the placental mammals.

ELAH FEDER: That’s us.

GREGORY BERNS: That’s us. And that’s pretty much all the mammals in the rest of the world. And so you had this kind of line of mammals evolving pretty much on their own in Australia. And you mentioned convergent evolution. And so the Tasmanian tiger, or the thylacine, actually ended up being what we call the apex predator in Australia. And so what did they prey on?

Well, they preyed on the other animals, which would include things like kangaroos, and wallabies, and other little animals. And so we think what happened was that they evolved to kind of look like an animal that preys on other small animals. And so we know those types of animals as things like coyotes, and wolves, and dogs. But in Australia, they were Tasmanian tigers, except they were marsupials.

IRA FLATOW: Wait. If you say they’re marsupials, did they have a pouch like a kangaroo did?

GREGORY BERNS: They did. They had a rear-facing pouch, so not the pouch that everyone knows kangaroos have. They had a rear-facing one, meaning the young kind of looked out backwards.

ELAH FEDER: So zooming forward to the present, they used to be apex predators. But by all– well, not by all accounts. By many accounts, they are now gone. What happened to these animals?

GREGORY BERNS: Yeah, so what happened– I mean, we don’t know exactly, but we can kind of piece together this story. It’s kind of like a crime scene, so we’re trying to do this forensically. So we know that thylacines existed on the mainland of Australia at least until– probably about 4,000 or 5,000 years ago. Because there have been remains found that have been carbon dated to about 4,000 years ago.

And what’s interesting is that period of time– there were also people in Australia by then– the Aboriginals. So humans started occupying Australia probably about 20,000, 30,000 years ago. And we know that the Aboriginals were aware of the thylacines, because you can find cave art showing them. And so there was this– it’s a very deep relationship to them.

IRA FLATOW: That’s interesting. Wow. Keep going.

GREGORY BERNS: Yeah. And so the other thing that was going on in this period of time is this was also the period of the last Ice Age, which means that the oceans were lower. And so Australia, the mainland, was actually connected to Tasmania. Now, Tasmania is an island.

And it’s south of Australia, kind of between Australia and Antarctica. So it’s really far south. But they were actually connected by a land bridge. So the thylacines, as well as the people, were able to move freely. And then as the Ice Age ended, the glaciers melted. The seas rose, and Tasmania was cut off from the mainland.

So you had this population of thylacines on the mainland. And then you had a population that was cut off in Tasmania. Now, for reasons we’re not totally sure, the mainland thylacines seemed to have disappeared. We don’t know if it’s because of conflict with the humans. Maybe they were hunted. Maybe their dogs competed with them.

Or maybe it was just simply climate change. Because before that, mainland Australia was much wetter and more temperate than it is now. So you ended up with just a small population of these creatures on the island of Tasmania. And then the British colonialists arrived. And that was the end of the story–

ELAH FEDER: Wait.

GREGORY BERNS: –pretty much.

ELAH FEDER: I mean, just to spell it out, what did the colonialists do?

GREGORY BERNS: Well, the colonialists wanted to turn Tasmania pretty much into farming land. And so they brought their sheep with them. And mysteriously, their sheep started disappearing, and they were killed. And they all thought that this thylacine was the one doing it.

And so there was a bounty put out on the thylacines along– actually, with wild dogs, too. And so everyone just started killing off the thylacines, because they were predating on the sheep. Although, it actually remains debatable how much the thylacines were responsible for that.

ELAH FEDER: Really? So they might have been falsely implicated.

GREGORY BERNS: I believe so.

IRA FLATOW: Wow. Last time we talked, Greg– I know you’re a neuroscientist. And last time we talked, you told me you’d been studying dogs a lot. And you actually trained a dog to sit still inside an MRI machine, so that you could study its brain. How do you go about finding and studying a dead Tasmanian tiger’s brain?

GREGORY BERNS: They’re as rare as hen’s teeth. So there’s kind of a– I don’t want to say a secret order of the thylacine. But there is a very active international community of people interested in all things thylacine. And so one person, that guy named Stephen Sleightholme, has compiled a database of all the known thylacine specimens in the world. And so I wrote to him.

And I asked him. I said, do you know? Are there any brains left anywhere? Now, as you said, I’m interested in brains. And so what I wanted to know is even though a thylacine kind of looks like a dog, I wondered what their brains looked like. And it turns out that there are four known brains left intact in the world. And as luck would have it, the Smithsonian has one of them, so I borrowed it.

IRA FLATOW: That’s cool. I’m Ira Flatow. This is Science Friday from WNYC Studios, talking with Elah Feder about the Tasmanian tiger.

ELAH FEDER: And Professor Gregory Berns. So what did you figure out when you took a look at these brains– or this brain?

GREGORY BERNS: Well, we actually know everything about this brain in the sense that we know the animal that it came from. It was completely documented. It came from a tiger that was captured in a town called Launceston in Tasmania in 1902.

They brought this tiger over, across the Pacific Ocean and then by rail, all the way to the National Zoo in Washington. And then when they got this tiger there, they realized they didn’t have just one tiger. They actually had four. Because there were three in her pouch.

She was a mother. And unfortunately, she died. And two of the pups survived. And they lived at the National Zoo until they died. And so we know everything about them. And when I got this brain, it was actually quite shrunken, kind of the size of a walnut.

And we knew from the records that it didn’t start out that way. It had actually shrunk to a third of the original size. But we were somehow able to coax enough signal out of it when we put it in the MRI, that we could reconstruct many of the pathways that exist in the thylacine’s brain.

ELAH FEDER: And so actually, we’re almost out of time. So I should ask the question that everyone has been wondering about. What do you think? Are they still around?

GREGORY BERNS: As much as anyone, I would love for them to be around. And I went to Tasmania to look for them myself. And obviously, I didn’t find any. Personally, I don’t think they’re there. I would like to keep up hope for them. But actually, I’ve thought about this a lot. And I think kind of keeping the hope alive actually does a disservice to the other animals that are disappearing as we speak.

IRA FLATOW: There you go. OK.

ELAH FEDER: Wait. Before you go, Ira. So I need your verdict.

[LAUGHTER]

On a scale of 1 to 10– baby pandas. How charismatic are the– and please, before you answer, bear in mind all that they’ve been through.

IRA FLATOW: OK. Well, how can you not feel that an animal created by committee– it has a pouch like a kangaroo. It looks like a dog and has stripes of a tiger. How could that not be cute? So it’s really– I think it’s a really cute animal. It wins.

ELAH FEDER: I need a rating.

IRA FLATOW: I’ll give it an eight and a half.

ELAH FEDER: Eight and a half? Greg?

GREGORY BERNS: 11. It is off the charts. This is like– it blows away the baby panda. This is polar bear territory.

ELAH FEDER: OK. Well, thank you very much, Greg and maybe Ira. And thank you, also, to Neil Waters who spoke with me earlier this week.

IRA FLATOW: And that’s about all the time we’ve got. Our guest, Gregory Berns, is a professor of psychology at Emory University. If you want to learn more about Tasmanian tigers and what Greg and Neil have been doing, go to sciencefriday.com/cute.

And of course, on Science Friday VoxPop app, we want you to nominate the next charismatic creature. We feature slime molds. And now, we have Tasmanian tigers. What’s next? Please go nominate the next charismatic creature on the Science Friday VoxPop app, wherever you get your apps.

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