Luke Tipple is joined by Dr. Tristan Guttridge to discuss the social and behavioral intelligence of sharks.
The discussion turns this week to sharks’ intelligence, and how it varies among species. Host Luke Tipple is joined by Dr. Tristan Guttridge, a behavioral ecologist and veteran of Shark Week whose research has tackled the social smarts, and even personalities, of different kinds of sharks. He sheds light on why we shouldn’t just think of them as dumb fish with rows of razor-sharp teeth. And at the end, our researcher Sierra Kehoe tells us about shark hypnosis.
Shark Week continues all week long on Discovery starting at 8p ET. For the latest, head to SharkWeek.com.
Find episode transcripts here: https://shark-weeks-daily-bite.simplecast.com/episodes/s4-ep5-how-smart-are-sharks-tristan-guttridge
00:00:00:00 - 00:00:07:15
Luke Tipple
Today, we're going to answer the question, how smart are sharks? And in our shark bite, we'll learn exactly what happens when a shark gets hypnotized.
00:00:07:17 - 00:00:18:05
Unknown
You’re listening to the Shark Week Podcast.
00:00:18:07 - 00:00:35:09
Luke Tipple
G’day, everyone, and welcome to the Shark Week, the podcast. I'm your host, Luke Tipple. And today we've got a really fun episode because we're going to answer an age old trope about sharks. Now, before we get too deep into things, make sure you subscribe to this channel. Like the video and ring that little bell so you'll never miss another one of our weekly podcasts.
00:00:35:11 - 00:00:48:19
Luke Tipple
The ocean is home to some of the smartest animals on the planet. Dolphins, for example, have their own language. They can learn language. They can even recognize themselves on a mirror, which is something that only humans and humanlike animals can do. If you look at things like.
00:00:49:01 - 00:01:00:02
Luke Tipple
Octopus, I mean, those things that crazy smart. And when you think about it, humans came from the ocean. So it should be no surprise that the ocean is home to intelligence. But when we think.
00:01:00:22 - 00:01:14:13
Luke Tipple
About intelligent animals these days, would we ever put sharks on that map of intelligence? Most people think it's just a dumb fish. But how smart are sharks? My guest today is Dr. Tristan Guttridge, and he's fascinated.
00:01:15:04 - 00:01:32:19
Luke Tipple
By that question. He's done a lot of work on it for him. It started with his doctoral thesis where he took on the social behavior of lemon sharks, and he found that, yes, indeed, they do have a complex social behavior. But what about other things like can sharks learn a task? Can they teach each other tasks or would they even want to?
00:01:32:21 - 00:01:43:10
Luke Tipple
Can they retain memories? Got lots of questions about this. So I'm welcoming Dr. Guttridge. Welcome back to Shark Week, the podcast, mate. It's really good to see you. Let's dive right in. How smart are sharks?
00:01:43:10 - 00:02:00:21
Tristan Guttridge
So we worked on a project about ten years ago where we work with these little baby Port Jackson sharks. And it was actually in Australia and I would go down to the dock and I would give a crate of beer to this fisherman and he would give me 20 Port Jackson sharks. And that's how that's how I got the sharks to run the experiments.
00:02:00:23 - 00:02:06:17
Luke Tipple
Yeah. For anyone listening, you can buy anything with beer in Australia that it's a legend, the myth. And it's absolutely true.
00:02:06:20 - 00:02:30:00
Tristan Guttridge
But it was just the easiest way to get hold of these animals. He was catching them. And. And so I got these animals and I was training them in captivity. And we basically ran a conditioning experiment where we paired either an underwater LED light or a bubbler presentation with a piece of food and the sharks would all of them picked it up within about ten days.
00:02:30:06 - 00:02:46:13
Tristan Guttridge
Now I had to do six replicates per day with each animal. And I have videos of these little Port Jackson sharks. The moment the public got presented, they'd be going over and sucking on these bubbles, even though there's no food in the water. And we retested them 4 to 6 weeks later and they would they could do the same thing.
00:02:46:13 - 00:02:53:01
Tristan Guttridge
They stopped by biting the bubbles straight away. So they have this capacity to learn and able to remember. Well, I think.
00:02:53:01 - 00:03:07:12
Luke Tipple
You know, somebody listening might say, yeah, that makes sense. We've got sharks who are learning how to eat and that's what sharks do. They're mindless eating machines that go around and bite things. What evidence do we have of any other type of intelligence other than them trying to capitalize on a feeding opportunity?
00:03:07:14 - 00:03:35:12
Tristan Guttridge
Right. Well, there's social intelligence, too. And, you know, you think about us, we're a very social animal. I think we're more sympathetic and we relate more to animals that are social dolphins. Elephants, lions and sharks are actually much more social than we think, too. I did a series of experiments working with lemon sharks in the mangroves, this little guy behind me, and I would sit on towers and watch them interact with each other and every single high tide.
00:03:35:12 - 00:03:55:06
Tristan Guttridge
These little sharks would come into the mangroves, they'd follow each other, and they form these big kind of social groups only up to about 20 animals. But what I found was that they had preferred individuals, they had sharks that they would prefer to associate with white bodies, basically, or familiar individuals. So that made us think, well, okay, well, maybe they actually can recognize individuals, too.
00:03:55:08 - 00:04:03:11
Tristan Guttridge
And we even found that in lemon sharks there was this continuum of sociality that some were more social than others.
00:04:03:13 - 00:04:07:06
Luke Tipple
Can we infer that different species are smarter than others then?
00:04:07:08 - 00:04:24:02
Tristan Guttridge
A I mean, when I first started working with the Port Jackson Sharks, I have to say there are a lot of people telling me they're not going to learn a thing. They are literally a swimming nose, you know, a snuffling pig, basically, that lives in the ocean and they're not going to learn anything. And I proved them wrong.
00:04:24:07 - 00:04:47:00
Tristan Guttridge
They learned. But what was interesting is we tried to we we first did the experiment where we used an underwater light and it really didn't work very well. I did get an association, but it took a lot it was a lot harder to get than the bubbles. So I think it's it's dependent on on the the stimuli and things that you use and, you know, sharks, there's huge differences in, you know, their sensory capability.
00:04:47:01 - 00:04:58:05
Tristan Guttridge
And some are much more visual than others. Some have much bigger eyes, some have much smaller eyes, some are more lateral line specialists like you can't of bull sharks. They have really little beady eyes. So sure. You know, as you know, I mean, can.
00:04:58:05 - 00:05:17:08
Luke Tipple
We put some some kind of parallel to it? Like could we say, hey, the bigger the shark, the more solitary it is, the smarter it is or the the more schooling behavior a species exhibits, the more socially intelligent they are. Like, if somebody is going to say, you know, what is the smartest shark? Is there a simple answer to that?
00:05:17:13 - 00:05:43:16
Tristan Guttridge
I mean, most people would talk about the brain mass to body ratio. And across all that, you know, is I can't remember how many species they've they've looked at the brain volume in different parts of it. But I think it's something like 80 or 100, quite a few representative of of various orders as well. And your scalloped hammerheads, your most social species have a have a much higher brain master body mass ratio than your port Jackson sharks.
00:05:43:18 - 00:06:02:18
Tristan Guttridge
But they are both social but in different ways. And there seems to be more social communication with the scalloped hammerheads. And there does seem to be this association with the more complex the brain is. It tends to be with species that are living in more complex environments like reef systems and stuff as well.
00:06:02:18 - 00:06:24:08
Luke Tipple
I wonder with, I've chatted to a lot of fishermen and their other kind of in two camps they say, you know, sharks are just super dumb. They'll come and eat anything that's like flapping around in the water or they're super smart and they'll wait and they'll strike at the best moment. And I kind of look at that and I go, Well, sharks are obviously associating, say, a fishing boat with a feeding opportunity, being able to maybe get an easy meal.
00:06:24:10 - 00:06:35:19
Luke Tipple
But then you see so many sharks swimming around with like hooks in their mouths, like wouldn't they learn that there is a massive deterrent to going out for that easy food when they're been perfectly capable of feeding themselves for 400 some million years?
00:06:35:21 - 00:06:51:08
Tristan Guttridge
Yeah, but the reward outweighs the cost, you know, and these animals are living on the edge of, you know, they, you know, if a food resource is predictable in time and place, why would you not take advantage of it? You know, and of.
00:06:51:08 - 00:06:52:21
Luke Tipple
Cause you might get some new jewelry.
00:06:52:23 - 00:07:15:08
Tristan Guttridge
There and it kind of hurts. I think there was a study done a few years ago in French Polynesia or somewhere like that where they showed hook avoidance by some of these sharks that they learn to avoid certain areas because they'd been hooked a couple of times. And I've definitely I've seen both sides of it. I've seen, you know, I've caught a nurse shark on a on a hook released and then caught it an hour later.
00:07:15:08 - 00:07:29:03
Tristan Guttridge
And I'm like, What are you doing, buddy? Why do I ask that? Yeah, I come back here, but it's like, mate, maybe that shark hasn't said for like a week. And so it's motivation to feed is is extremely high compared to another species. You know.
00:07:29:05 - 00:07:38:14
Luke Tipple
While we're kind of on this topic, I want to draw a line for people between the whole mistaken identity kind of argument because that's something I've always had a problem with.
00:07:38:16 - 00:07:44:09
Tristan Guttridge
Yeah, it's you. What do you mean you've had a problem with You don't think that they're mistaken?
00:07:44:11 - 00:08:05:16
Luke Tipple
I don't think they're mistaking it, No. Make it very clear for people. Any time somebody gets bitten, a media organization who is being irresponsible will say shark attack, vicious monster, blah, blah, blah. A media organization who is being, let's say kind will say I was of mistaken identity. You know, the shark made a mistake and I'm like neither of those are true.
00:08:05:16 - 00:08:27:15
Tristan Guttridge
I think it could be both. I do think in some instances these sharks are so motivated. And and I think the environment you've got to remember that these animals are in an environment where you've got current changes. You've go and visibility changes, you've got other sharks, you've got prey, you've got predators. You know, they got to make quick decisions. And I do think.
00:08:28:16 - 00:08:34:11
Luke Tipple
Okay, so let's rule out turbidity, Let's rule out surf zone, let's rule out some of the you know.
00:08:34:13 - 00:08:38:14
Tristan Guttridge
You should watch dangerous waters. There's some interesting stuff in that show, I can tell you now.
00:08:38:16 - 00:09:02:04
Luke Tipple
Okay. So Chris is talking about dangerous waters. It is on Shark Week this year. You definitely check it out. And we will I will watch it. But let's take out a fisherman who's standing in the middle of a, you know, a cycle of migrating fish and getting bitten by. All those. Let's talk about a great white shark hitting a swimmer or a tiger shark in crystal clear water in Hawaii coming up and taking the leg off a surfer.
00:09:02:06 - 00:09:06:10
Luke Tipple
Aare they making a mistake or are they just being opportunistic and trying something new?
00:09:06:15 - 00:09:25:20
Tristan Guttridge
We got to think about these animals, you know, when they're searching for prey in the environment, you know, they have like a search pattern in their head, like a maybe a shape, a smell, you know, that that takes the box, you know, And then obviously, through repeated encounters with all these different prey items and things, they get a reward.
00:09:25:22 - 00:09:41:18
Tristan Guttridge
And so they'll maybe they have this image of a this, you know, that that's one of the things they look for. Okay. Well, that that that's take the images there. Okay. Well, it's moving at the surface. That's ticked. Well, I'm going to go in and check it out like so, you know, you think about the decisions these animals are making.
00:09:41:18 - 00:09:59:17
Tristan Guttridge
I mean, you know, it is I think it's a lot there's a lot more going on. And I also think that it's important to give credit to these animals, too. You think about a white shark, a full tailed going for a seal that's maneuvering the swimming the way that a seal can sweep. You know, these are highly agile animals.
00:09:59:19 - 00:10:19:04
Tristan Guttridge
And you've got a white shark, what, 15, 20 meters down, 50 feet down, something like that. There's monitoring an animal that's at the surface. And he's got all these environmental conditions that are changing constantly. It's got a search pattern in its head of what it should be going for, what prey item should be. And then it makes a split decision.
00:10:19:06 - 00:10:27:09
Tristan Guttridge
I could say that's mistaken identity because to the shark that is appropriate to do, you know.
00:10:27:15 - 00:10:40:10
Luke Tipple
I mean, I think you're right. The way you describe it just made a lot of sense to me. And I haven't heard it that way before where it's like, you know, you're checking those little boxes of. Yes. That the outline kind of looks like it from a long way away. Yes. It's in a area where I'm used to seeing that outline kind of from a long way away.
00:10:40:12 - 00:10:59:14
Luke Tipple
But then there's that moment of getting close to an accelerating. So I wonder if there is that kind of check, check, check. And then they go into predation mode. And once you're in that mode, then it's like it's really hard to dissuade them because, you know, they they start like putting the systems into gear. And then there are fighter pilot, you know, triangulating on the prey.
00:10:59:16 - 00:11:00:01
Tristan Guttridge
Right.
00:11:00:03 - 00:11:03:05
Luke Tipple
And they may as well spend the energy and take a bite and see what it is.
00:11:03:07 - 00:11:26:23
Tristan Guttridge
True. But we also, you know, we don't see the predation events where they they've gone in for a human but not taken it. Do you know what I mean? We we only see the one that has happened. You know, we don't know whether that could have been, you know, hundreds of occasions, You know, some of these locations where you see white sharks and people interact, where a shark was like, yeah, that's a prey. Oh, no it’s not.
00:11:30:20 - 00:11:42:11
Luke Tipple
There was a piece that just came out recently exactly about this. Sierra, could you look it up for me? Something like 97% of the time surfers are in the water. They're around a white shark. It was a study in California race.
00:11:42:11 - 00:11:43:11
Tristan Guttridge
Yeah. Recently. Yeah.
00:11:43:16 - 00:11:46:15
Luke Tipple
Yeah. So if you can pull that article for us here, because that was really interesting.
00:11:46:19 - 00:12:06:10
Sierra Kehoe
Yeah, I have it right here. It's a surfer dot com article and it says that juvenile white sharks were often observed within 50 yards of where the waves break. So that's where, you know, surfers and swimmers are. And that in San Diego County and Santa Barbara County, specifically in California, juvenile great whites were around, were swimming near people.
00:12:06:10 - 00:12:07:19
Sierra Kehoe
97% of the time.
00:12:08:00 - 00:12:20:12
Luke Tipple
They go obviously there's a lot of the time, there's a lot of sharks surrounding surfers, for example, making the decision not to bite. So I guess that shows what we're talking about, Right. So do you think sharks can have personalities?
00:12:20:14 - 00:12:39:08
Tristan Guttridge
We know that they can have personalities. Sharks definitely can have personalities. There's been a number of studies that have shown it. You know, again, this was something that was shown with with lemon sharks in the Bahamas, in Bimini. We did experiments looking at social personality. We had some that were more social than others, some that would follow in more groups than others.
00:12:39:10 - 00:12:53:01
Tristan Guttridge
And the good thing is that, you know, you test them again to make sure it's consistent. That's the big thing to be able to show that something, you know, behaves in a consistent way is you have to test them once and then usually have a week or two weeks. But between the two tests and see that they correlate.
00:12:53:01 - 00:13:10:02
Tristan Guttridge
And the sharks that were not none were antisocial. All, you know, they always kind of hung out with other sharks, but some did more than others. And they were consistently doing that. You know, anyone that's been diving with these animals, you know, can tell that there's there seems to be this different personalities. And we've we've shown this empirically with with hundreds of sharks.
00:13:10:02 - 00:13:13:15
Tristan Guttridge
We're not just talking ten animals. We tested 150 animals.
00:13:13:17 - 00:13:32:03
Luke Tipple
Oh, certainly. I mean, especially when you're out diving in a regular dive location, you get to know the certain animals by their markings or their size or whatever. You get to know how they like to feed, whether they will come in and feed, whether they'll approach divers. And to me, that certainly seems like at least an extreme behavioral characteristic, if not natural personality.
00:13:32:03 - 00:13:36:01
Luke Tipple
You know, they do seem kind of friendly in a water.
00:13:36:01 - 00:13:38:01
Tristan Guttridge
I know it's tricky. Yeah, I.
00:13:38:01 - 00:14:00:00
Luke Tipple
Really hate doing that. But it's the easiest way for us as humans to do that because we have to convey our intelligence and emotions onto something to be able to understand it most of the time. And, and sometimes that's how we then care about them. So like we talk about dolphins having family groups and stuff, why would we talk about that if we didn't know what that feels like ourselves, Right?
00:14:00:02 - 00:14:10:09
Luke Tipple
Yeah. So if we're going to talk about sharks in a way that is scientifically sound, then why not infer some of those characteristics so that we can make people care about them a little bit more?
00:14:10:14 - 00:14:32:09
Tristan Guttridge
Right, Exactly. And, you know, when you talk about animals to your kids and you can relate them to, you know, the kids growing up and them having friends and things like that, then they become more interested in them as well. So I definitely think it changes people's perception when you can show that these animals are more complex behaviorally than than just this dumb swimming nose.
00:14:33:01 - 00:14:43:11
Luke Tipple
Let's make it easy for people here. Let's sum it up and say, you know, sharks are obviously a very intelligent creature, but what's a parallel? How should people think of them? Are they a dumb fish or are they a what?
00:14:43:12 - 00:15:01:04
Tristan Guttridge
No, I mean, if you think about sharks, most of sharks live for a similar like, you know, have a similar life to us. You know, these are animals that are not reaching maturity to the 12 or 14 years of age. Most of them, you know, they're surviving till a 50, 60, maybe 80 years of age. So they have long life histories.
00:15:01:04 - 00:15:37:23
Tristan Guttridge
They live in the ocean. You know, they have environments that are changing, some that are predictable. You know, like these animals have evolved over 400 million years. Like it absolutely makes sense that they have complex behavioral capabilities. You know, for us to even think that an animal that's been on the planet for 400 million years that leaves us, you know, some animals up to like 400 years of age to think that they can't learn, that they don't have complex social hierarchies or, you know, they can migrate from one place to another a thousand kilometers apart and go exactly back to where they were a year before.
00:15:38:01 - 00:15:41:08
Tristan Guttridge
They are smart. They have to be smart to be able to do that.
00:15:41:10 - 00:15:53:19
Luke Tipple
Well, we're seeing you're all over the place and you've got a couple of shows on Discovery Channel this year on Shark Week. What was kind of your favorite scene or experiment or whatever with Jaws versus Meg? Because it's tough to pierce an animal that doesn't exist anymore to it to a real animal. Right?
00:15:53:21 - 00:16:18:14
Tristan Guttridge
Right. Okay. The best scene my most exciting moment was I was in the cage with Andy Casagrande. We've got this vertical ladder that's going from another cage. That kinescope is in opposite us. The ladder goes all the way down to the bottom, and we've got this crane with a tuna that's dropping it down in front of us. And then we're trying to get these white sharks to launch up to measure vertical speed.
00:16:18:16 - 00:16:38:14
Tristan Guttridge
And it was I mean, I was it's like a game of sharks and ladders or sharks and shoots. Apparently they call it in in in the US. But it was it was utterly amazing. We had like this massive five meter long 18 foot female white shark just launch. I mean, we never thought it would happen, but it literally launched right up the ladder a top, top speed.
00:16:38:16 - 00:16:40:14
Tristan Guttridge
So that was really exciting because it's.
00:16:40:14 - 00:16:43:14
Luke Tipple
Hard smash into the ladder or did it kind of land off to the side?
00:16:43:14 - 00:17:03:12
Tristan Guttridge
No, it took the tuna. It followed up and took. Yeah. I mean, honestly, you have to say it was so much fun. I was just like a little kid. I was commentating. I was like a commentator in, like a, you know, like a football match just in this box, just, just, you know, commentating about how the sharks were interacting with the with the with the bay, you know, are they coming?
00:17:03:12 - 00:17:07:14
Tristan Guttridge
Are they coming? Move them. Move the tuna up. Yeah. This is really cool.
00:17:07:19 - 00:17:09:12
Luke Tipple
Yeah, that's crazy. You get paid for this, huh?
00:17:09:12 - 00:17:10:14
Tristan Guttridge
I know. I was thinking that.
00:17:10:17 - 00:17:10:23
Luke Tipple
Know that.
00:17:10:23 - 00:17:30:13
Tristan Guttridge
Fun? Yeah. In that moment, I was like, really? I'm being paid to. To do this. But, yeah, that was. That was really cool. And, you know, it's just trying to allow people to visualize the, you know, the power and the attributes of these animals in a different way doing these kind of demonstrations. So, yeah, it's a lot of fun.
00:17:30:15 - 00:17:36:18
Luke Tipple
All right. It's time for the shark bite where Sierra leaves us with a cool ocean fact to end the show. What have you got for us today, Sierra?
00:17:36:20 - 00:17:53:15
Sierra Kehoe
Yeah. So we've all heard about tonic immobility, which is when when a shark gets flipped over a lot of different species, they go into this trance like state, like they've been hypnotized. We've all heard this fact, but I bet a lot of people didn't know that orcas actually capitalize on this and use it to hunt sharks.
00:17:53:21 - 00:17:55:04
Luke Tipple
Tell us more.
00:17:55:06 - 00:18:07:17
Sierra Kehoe
So the orcas, they are, you know, when they go into hunt these sharks, they end up maneuvering them around so that the shark gets flipped over and then they go into this trance like state and then make it really easy for the orcas to kill them.
00:18:07:19 - 00:18:16:23
Luke Tipple
Yeah, it's almost like imagine if you saw a turtle, kind of like wandering along the turtle over there on its back and it really can't do much. Have you seen what they do to them afterwards?
00:18:17:00 - 00:18:18:00
Sierra Kehoe
No, I haven't.
00:18:18:02 - 00:18:34:06
Luke Tipple
Oh, okay. So this is it's actually pretty brutal. But the, the orcas are so smart that they're managing to flip over these couple thousand pound. Great Whites. Then grabbing onto their pectoral fins and pulling them apart like something from the gladiator days, you know, pulling up.
00:18:34:22 - 00:18:44:03
Luke Tipple
Splitting them down the middle because that's like a natural break point for the sharks, exposing their liver, eating the liver, and then leaving the rest of the carcass to just.
00:18:44:03 - 00:18:44:15
Sierra Kehoe
Brutal.
00:18:44:19 - 00:18:57:11
Luke Tipple
Decomposition is slightly brutal. It's it's crazy. Now, I'm sure this isn't what the mechanism was originally designed evolutionarily to do to help orcas out. But do you know why else it would be beneficial?
00:18:57:13 - 00:19:13:05
Sierra Kehoe
So it's not nothing's been proven yet, but there are some hypotheses that it could be a defensive strategy. I mean, we just talked about how orcas use this to kill them, but that when they get flipped over and they're ultimately playing dead, but it might actually deter some predators. It's one hypothesis.
00:19:13:11 - 00:19:26:10
Luke Tipple
But yeah, it's one of those weird phenomenon that we don't really understand yet, but we do know that physiologically it slows them down there, that presumably the neural processes slow down a little bit and they're more susceptible to what's going on around them. So good adaptation, bad adaptation, I don't know. What do you think?
00:19:30:18 - 00:19:32:02
Sierra Kehoe
A little bit of both, I think.
00:19:32:04 - 00:19:32:22
Luke Tipple
Thanks Sierra.
00:19:33:00 - 00:19:37:20
Sierra Kehoe
You're welcome.
00:19:37:22 - 00:19:52:11
Luke Tipple
That's it for today's podcast. I want to thank you for joining us. And I hope that today you've learned just how smart sharks are. I want to thank our guest, Dr. Tristan Guttridge, for joining us. His work is incredible and you really should check out his nonprofit. It's called Saving the Blue dot Org. They're doing some really good work.
00:19:52:13 - 00:19:56:01
Luke Tipple
Until next time, I'm Luke Tipple. I'll chat to you soon.
00:19:56:03 - 00:20:03:12
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