Endless Thread - Asking Science About Giraffe

Episode Date: March 24, 2023

On a sunny day in March 2020, researchers in South Africa discovered the bodies of two giraffes. From what they could tell, the giraffes had died a few days earlier. But the cause was a mystery. To understand what happened, producer Dean Russell turned to the subreddit AskScience. He discusses his findings with Endless Thread co-hosts Amory Sivertson and Ben Brock Johnson. Credits: This episode was written and produced by Dean Russell. Mixing and sound design by Matt Reed. Amory Sivertson and Ben Brock Johnson are the co-hosts.

Support for endless thread comes from MathWorks, creator of MATLAB and Simulink Software, to design and develop engineered systems, accelerating the pace of discovery in engineering and science. Learn more at Mathworks.com. Support for WBUR comes from Is Business Broken, a podcast from the Mayrotra Institute at Boston University that explores questions like, why is innovation in healthcare so hard? Is ESG just greenwashing? of course, is business broken? Listen, wherever you get your podcasts. Hey, endless thread listeners. It's Ben Brock Johnson. I want to tell you about an event that's upcoming in Boston that I am so excited about. And it is put together from a bunch of crazy disaster movies. So if you like disaster movies and you like watching clips from disaster movies. And you like talking about ridiculous films from the 90s in 2000s and and Aughts and all the time that Hollywood has done a terrible job at talking about climate change.

I want you to come to this event. Dean Russell has been working on it with me. And Dean, how would you describe this experience for the audience that we're going to have? It's a choose your own disaster event where everyone gets to vote on what happens next in the great plot that we're moving through in our disaster movies. And it's going to be unlike anything we've ever done and we're really excited. And if you're an endless thread fan and you're a disaster movie fan, we encourage you to join us on April 21st, 2023. Just go to wbUR.org slash events and you will find this choose your own disaster event right there at page.

All right. We hope to see you. Let's party. Here's the show. WBUR Podcasts, Boston. Amory, Ben. Dean. Dean.

I'm going to start with something I read online recently. This is a mini murder mystery. Oh, boy. Does that mean the person, place, or thing that was murdered is miniature? Well, actually the opposite. It's March 2nd, 2020. and a team of researchers are trekking through this wildlife preserve in South Africa. And they come across these two female giraffes lying on their sides.

And it doesn't take long to discover that these two have unfortunately gone on to greener pastures. But there's something really strange about their deaths. the cause was an absolute head scratcher because these two giraffes looked besides the fact that they were dead, more or less fine, like nothing was wrong with them. Broken neck. A broken neck, they would be able to tell.

So I'm going to say that this is some little bug or parasite. Like driving under an overpass in a Volkswagen bug convertible? Is that not what you're thinking, Amory? No. No. No, I'm thinking of little critters that would be, you know, many, many, many feet below where their head is to notice them latching onto or biting or embedding themselves within that giraffe body. What about headbanging?

Could that be a thing? Like they were listening to rock music too loud and they head banged too hard, but their neck's so skinny that they just, no? That was like the number one thing that they considered. Yeah, for sure. So I will say, in this bushland preserve, which is called Rockwood, giraffes, which are like an animal that's considered vulnerable to extinction, they are highly monitored.

And the last time that these two had been seen with their herd was a few days earlier, in a storm. Now, that storm itself was like pretty brief, but it had done some damage to several game fences. And so naturally, you might think someone or something dangerous had got it. They kind of failed to see any gunshot wounds, though. There were no like lion claw marks. There were a few jackal bites, but like jackals are scavengers and, you know,

they don't really attack giraffes. And then they noticed this weird toxic smell, like ammonia, which was like emanating from their bodies. Oh, no. Did they eat something that was toxic? Something that's like hard to swallow because, you know, with the long throat, it just might take some wrong. Oh, you're poor giraffes. I love giraffes. Don't get, don't, please don't, you know, don't get me wrong.

I just. You're just fully appreciates. appreciating their anatomy. Yeah, that's right. The older giraffe, I will call her Gina. She was found lying on her left side. She had a broken right oesicone, which is like that horn-like bone on their skull.

Damn, Gina. Ococone. Yeah, and so they think maybe Gina fell. And her buddy, who I'll call Gabby, Gabby is lying 20 feet away, completely untouched. And it appears that they died at the same time. Like, as if they both just, like, short it out.

Wow, this is a real Thelma and Louise situation here. No, we know how they died. They got back in that Volkswagen you were talking about. Yeah. But, you know, maybe this is, like, the people who happen upon Thelma and Louise, and they're like, what? There's this car and they're, what? So the reason I bring this up is because, as I was, reading this. I was reading this in this like academic journal article by Siska SheeGen, which I am

sure I mispronounce and so please forgive me, Siska. But one of the researchers, she wrote this up and I was reminded of this old post on the subreddit, the subject of today's show, Ask Science. Doing a lot of talking. Does someone want to explain the deal with Ask Science? It's a community based around science questions in which people who might have some level of expertise respond to said questions with surprisingly effective answers most of the time. This is, in my honest opinion, my favorite subreddit. I love going through Ask Science.

I love seeing the ideas that people come up. with and I love seeing how they like solve things together. But so several years ago, someone posted a simple question that felt very relevant as I was reading this murder mystery because Gabby and Gina, as I said, they died in a storm. And this one post asks the question, do giraffes get struck by lightning more often than other animals. That is shocking, but it also, I guess, makes sense because if... It's quite shocking. Couldn't be more shocking. Shocking to the point of death. Does it make the hairs on the back of your neck go up by any chance? Well, I was going to say because I'm like, they're still not tall enough to be struck by lightning,

but if you think about their natural habitat, they might be the tallest thing in the area when lightning. strikes. Yeah. So Gina and Gabby got struck by a bolt of lightning at the same time. Well, before I get back to the mini murder mystery, I wanted to pull apart this more general question. Do giraffes get struck more often? And see if it actually tells us anything about what happened to Gina and Gabby. And we'll do that after the break. At Radio Lab, we love nothing. We love nothing more than nerding out about science. Neuroscience, chemistry. But, but we do also like to get into other kinds of stories. Stories about policing or politics. Country music. Hockey. Sex. Of bugs. Regardless of whether we're looking at science or not science, we bring a rigorous

curiosity to get you the answers. And hopefully make you see the world anew. Radio Lab, Adventures on the Edge of what we think we know. Wherever you get your podcast. There is something powerful about the sound of the human voice. Beautifully produced audio has the unique power to connect and inspire. Tell your organization's story with a custom podcast from City Space Productions, the Creative Studio from WBUR's Business Partnerships team. Become a thought leader. Recruit new talent.

Reach new audiences. Whatever your goal, we can help. Discover how the magic is made at WBUR.org slash creative studio. Ben, Amory, do either of you have any guesses before we dive in? Do giraffes get struck by lightning more often than other animals? My current feeling, Dean, is that, yes. Oh, that was a pun. I was like, I thought that you were hinting.

I'm sorry, I thought that you were hinting at the fact that maybe you knew even more. and so you were trying to play along with this theory for the current moment, but you were making a pun. My current feeling is also yes, but that it's so incredibly rare that the idea of posing this question is kind of silly, but maybe not. Maybe Dean has something that can ground us in the question. You know what? I actually called someone to help ground me because the, you know, giraffe science was, I don't know, it can be... Was it above your head?

Was it over your head, Dean? Oh my God. You know, I love this question because it really plays off of people's fascination and curiosity with giraffe. So this is Michael Brown. He's an ecologist at the D giraffe Conservation Foundation in Namibia. And he thinks, you know, this is a really interesting question. the giraffes he studies are like 15, 16, sometimes 20 feet tall. And it is true that sometimes lightning often actually strikes the tallest object.

But to say that they're more susceptible and more at risk than other animals, it's really tricky to say. You know, even though I could tell you that like 20 to 30 people are struck by lightning in the U.S. every year, there are no data on giraffes. Giraff live oftentimes in remote places, so collecting any data systematically on lightning strikes is inherently challenging thing to do. So all the accounts you have of animals getting struck by lightning are purely anecdotal.

Unrelated side note, is the plural of giraffe, giraffe? That was my second question to my... Michael, because I was like, what's going on here? Okay. Apparently, you can do it either way, either giraffes or giraffe. Well, I have a question. Aren't there telltale signs of singeing? You know, wouldn't their eyebrows be gone or something?

You know, like... Yeah. If these, say these giraffe were struck by lightning, I'm going with the no-s, S plural. Yeah, wouldn't they be a little toasty? So in 90% of documented cases of animal strikes, there are, yes, sing marks. There have been several cases of mass death, though, where like a bolt hits the ground and wipes out, say, 300 reindeer standing nearby, which actually happened in 2016.

Few, if any, singmarks. The electricity kind of just like hits the ground and then disperses. through the ground, up through one pair of legs, through vital organs, and down through the other pair. I know it's kind of macabre, but yeah, no sing marks. Regarding giraffes in this bigger question, someone on the subreddit by the name of Peacebringer used an architectural formula to calculate the likelihood of a strike based on height and width alone. I thought this was pretty cool and really complicated. I didn't understand it. But anyway, they calculated that the typical giraffe is 35 times more likely to be struck than, for example, a zebra.

Wow. But again, that formula is for buildings, and it depends on where the giraffe is, too. Several anecdotal cases I looked up were about zoo giraffes in Florida, which is the lightning capital of the United States, so less of a surprise there. And that's much more lightning-y than, say, South Africa, where Gina and Gabby were. People in the thread say most importantly, you have to take a step back and look at the biology of the animal. Look at the ecology. This one person suggested that because giraffes have long necks to eat from trees, they should be protected from lightning by those trees.

Oh, that's true. It's tricky too because like giraffes might be more likely to be struck by lightning, but zebras are more likely to be behind bars. Oh, boy. Yeah. I asked Michael about this sort of line of thought, like they're tall to eat trees, so aren't they protected? And he pointed out two major flaws that were interesting to me. First, it's actually not a given that giraffe have long necks for eating from trees.

scientists say that that's just one hypothesis. Whoa. Another is that they can see things from far distances, so that helps to keep them from being attacked by, you know, various things. And then one of the ones that has a bit more traction lately is what's called the Next for Sex hypothesis. Next for Sex. But tell me where to buy that t-shirt right now. Take my money, please, for the Nex for Sex t-shirt.

So the way this works is it's actually like males battling each other for mating partners. They'll line up next to each other and they'll swing those long necks and those big, heavy, bony skulls, almost like a mace, like a ball and chain and just wallop each other. and the animals with the heavier heads and the longer necks obviously can generate much more force and can do much more damage. All that energy is just concentrated largely in those osicones, those almost horn-like protuberances they have. And it's really pretty violent. But the animals with the longest necks can oftentimes do the most damage. Oh, okay.

I've been doing it wrong. Michael also pointed out that giraffes live in pretty diverse places. Forests, yes, but also open prairie, shrubby rockland with very few trees, which was the case with Gina and Gabby. Michael also told me that he's never seen a giraffe lie down in storms. They just kind of stand around and bear it. So, you know, they might very well be more vulnerable. At the same time, one thing I thought was really cool that I got from the subreddit,

relatively speaking, giraffe's natural habitat isn't very lightning-y. If you look at a map of where lightning strikes are less common in Africa, and then you look at a map of where giraffes have historically lived, they line up pretty exactly. So that's not a coincidence. That's giraffs knowing what's up? I mean, it's most likely what Michael called correlated covariance. So if you look at that map of lightning strikes,

you know, the most intense areas were over the Congo, over the Congo base, which also corresponds with some really, really dense, you know, forest, some rainforest areas. So it might not necessarily be that they're avoiding lightning strikes. of just trying to avoid other things. I think... But you've got to see these maps. They're...

Like, you could just lay them right on top of each other. They're pretty cool. Wow. Okay, so let's back up to Gina and Gapy. Two tall gals caught in the thunderstorm, open brushland, a few trees. After a necropsy, the researchers determined that most likely,

yeah, it was lightning. A bolt probably hit Gina in the Ossicon and then traveled down through her body into the ground and then back up into Gabby. Either that or it bounced off Gina and hit Gabby. A quick, tragic end. Wow. Wow. It ricocheted off the Ossacon.

That's quite a concept. But I have one more point to make that didn't come up in the subreddit. And that is the real threat. for giraffes. Yeah, so lightning strikes might not be a big threat to giraffe, but giraffe do face some significant threats across their range. By our best estimates across all of Africa, there's about 117,000 giraffe left in the wild. To put that in context, that's about one giraffe for every three to four African elephants, for instance. Tall as they are, lightning is a minor threat to giraffes. Even the ones I mentioned who died by lightning in those preserves and zoos in Florida,

I would argue that they didn't really die because of lightning. They died because they were in the wrong place at the wrong time. Because for centuries, giraffes have been pushed out of their habitats, mostly by human development. People need space, but giraffes need space too. And those spaces for drafts are shrinking. They're becoming more fragmented. Michael's main job at the giraffe conservation foundation is not to think about lightning. It's to secure safe, natural homes for these giraffes.

So they don't all end up in zoos in Florida worrying about lightning or something like that. Dean, thank you for this tall, tall tale. Oh Yeah, thank you