Episode 01: The (Forgotten) Amphibian Crisis with Dr. Joe Mendelson
Where have all the frogs gone?
In Episode 1 of Amphibian Rescue, we go back to the beginning. Herpetologist Dr. Joe Mendelson takes us through the earliest signs of global amphibian declines and the timeline of how scientists went from dismissing the idea to finally accepting that there was a crisis to respond to.
Joe recounts how scientists worldwide initially dismissed disappearances as bad years until patterns converged at the 1989 World Congress of Herpetology and later evidence pointed to disease. But it was not an easy path. The episode follows the slow recognition of chytridiomycosis, and Karen Lips’ documentation of a site’s chytrid arrival and subsequent crash. All of which kickstarted a global movement to respond to this crisis. This brought conservationists from around the world together in an unprecedented way—but more on that in Episode 2.
About our guest:
Dr. Joe Mendelson III is Director of Research at Zoo Atlanta and adjunct professor at Georgia Tech University. He has dedicated his career to taxonomy and herpetology, and was among the first responders to the amphibian decline crisis. He is also a guitarist in the Atlanta-based science punk-rock band Leucine Zipper and the Zinc Fingers.
Documents referenced in the episode:
- Crump, M., Hensley, F.R., & Clark, K.L. 1992. Apparent Decline of the Golden Toad: Underground or Extinct? Copeia.
- Longcore, J.E., Pessider, A.P., & Nichols, D.K. 1998. Batrachochytrium dendrobatidis gen. et sp. nov., a chytrid pathogenic to amphibians. Mycologia, 91(2), 219–227.
- Pessier, A.P., Nichols, D.K., Longcore, J.E., & Fuller, M.S. 1999. Cutaneous chytridiomycosis in poison dart frogs (Dendrobates spp.) and White’s tree frogs (Litoria caerulea). J Vet Diagn Invest 11:194-199.
- Lips, K.R., et al. 2006. Emerging infectious disease and the loss of biodiversity in a Neotropical amphibian community. PNAS 9 (103).
- First Amphibian Conservation Action Plan: Gascon, C., Collins, J. P., Moore, R. D., Church, D. R., McKay, J. E. and Mendelson, J. R. III (eds). 2007. Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group. Gland, Switzerland and Cambridge, UK. 64pp
- Website of the World Congress of Herpetology
Transcript
[00:00:00] Joe M.: Nobody even mentioned the word disease. No one was saying climate change, and importantly, no one was saying they were actually gone. All they were saying is that I can't find them. I distinctly remember sitting in this chair in this office with that phone getting the call saying, Joe, it's Karen. It happened. My team found a couple of dead frogs last night. This place is about to crash.
[00:00:32] María B.: Welcome to Amphibian Rescue, the Amphibian Ark Podcast. Amphibian Ark's mission is to rescue amphibians in crisis, especially those that cannot currently be protected in the wild with the ultimate goal of one day returning them to their safe and restored habitats. I am your host, Maria Braeuner, and I invite you to join me as we share these inspiring stories of how ex situ to conservation, collaboration, and science are [00:01:00] already giving amphibians a second chance and a future back in the wild.
[00:01:11] María B.: But before we get to those stories, let's go back to the beginning, before Amphibian Ark even existed. Before we even called it a crisis, a set of odd observations began to emerge, but for a long time, nobody even knew what to make of them. You see, the forests were still standing, the streams were still flowing, but the frogs were disappearing.
[00:01:35] María B.: In this first episode, I'm happy to be talking with renowned herpetologist, Dr. Joe Mendelson III, director of research at Zoo Atlanta, and adjunct professor at Georgia Tech University. Joe was there when it all began among the many scientists around the world who began asking themselves, where have all the frogs gone?
[00:01:54] María B.: In this episode, we'll hear Joe's side of the story and how amphibians, often these small, overlooked animals, ultimately brought the world together. Now join me in learning more about Joe, who has dedicated his career to taxonomy and herpetology. Although his passion for herpetology began way before his academic career.
[00:02:15] Joe M.: Well, I was, uh, the stereotypical little nature nerd kid that was constantly outside, turning over rocks, catching worms, centipedes, frogs, lizards, things like that. And I became enamored of reptiles. Reptiles [00:02:30] first, amphibians second, and rep. I say amphibians second because. Most of my experience was in Southern California, like around San Diego, California.
[00:02:39] Joe M.: And, uh, the amphibian diversity and abundance is just kind of low there. It's, it's, it's, it's very, very dry. And so I was surrounded by far more reptiles than amphibians. So as a kid, I was drawn to what I could find, which was reptiles. And on the back of my mind always was one day I want to know a tropical forest.
[00:02:59] Joe M.: That was [00:03:00] very exotic for a kid from the United States, and then it was in graduate school that I finally, uh, had my first opportunity to go to the tropics, and that happened to be Guatemala. And then that, um, it was there that I really noticed amphibians because the diversity was so high and their behaviors, I just, I was just stunned.
[00:03:22] Joe M.: I'd never seen anything. I'd heard about it, but when I saw it, I finally. I finally understood. It's like, oh, amphibians are really, [00:03:30] really interesting and diverse. I never really had the opportunity to, to embrace that. And when I did, I was hooked
[00:03:38] María B.: in, in San Diego. Was, how was the herping there there with amphibians then?
[00:03:43] María B.: 'cause you, you mentioned there was low, but I, I imagine there was something Yeah.
[00:03:46] Joe M.: What, what was interesting for me, I had a, my field guide. To the western reptiles and amphibians, the standard book for, for that part of the United States. And my goal in like in [00:04:00] high school was to find every species in San Diego County of reptile and amphibian.
[00:04:05] Joe M.: And I did pretty well. I, I didn't find everything by the time I had to move away, but I, I found most things. But what really struck me was that the, for the amphibians there were, uh, there was one tree frog that was very easy to find. If the weather was correct in the winter when it rained, they were, they were abundant.
[00:04:24] Joe M.: And when I was a kid, there were two species that were easy to find, [00:04:30] the tree frog and the western toad. And then from my childhood, through high school, that toad completely disappeared from my neighborhood where I was. I remember being able to find, you know, in when I was 12, I could go out and find 15 or 20 in a night.
[00:04:48] Joe M.: By the time I was 17, I couldn't find any. This was in the seventies. No one was talking about amphibian declines or crisis. And I was a kid. I didn't know there was no internet. I had no one to talk to. [00:05:00] I had no basis for this. But I remember noticing, it's like, wow, the toads are just gone. And then also, there were two species, uh, that I could think of the, with the yellow legged frog and the red-legged frog that I, I simply could not find.
[00:05:17] Joe M.: I couldn't find them. I didn't know why, and I had no one to ask, and so I just, I couldn't find them. I was a little bit frustrated. And then when I took a herpetology class in college, I realized, oh, I couldn't [00:05:30] find them because they were gone. They had disappeared from most of Southern California. The, I learned that the reason was because of the invasive bullfrogs, and I thought, oh, oh, now I'm learning something.
[00:05:44] Joe M.: Uh. I could find the bull frogs when I was a kid, but I did not know they were invasive. I did not know that they weren't native to San Diego County. They were, they were pretty common. And I thought, oh, okay. Somebody introduced the bull frogs and they out competed or just directly [00:06:00] consumed and ate the native frogs.
[00:06:04] Joe M.: And so that was the, the, these sort of observations and stories in my, in my youth were sort of gelling to, to get me thinking about. Amphibian conservation for the first time. 'cause all I'd been doing up till then was just checklisting trying to find everything. And then I was coming through, you know, through my experience, I was realizing, oh, there are things I cannot find.
[00:06:27] Joe M.: And it's, it's, it's because they're not [00:06:30] there. That concept was new to me that it's like, oh, things disappear. I knew about endangered species, but that was all bald eagle and California condor, the very charismatic ones, you know, and giant panda, blue whale. These things, it didn't occur to me that there could be endangered little frogs and, and that nobody really knew or cared in, in the, in the public sense.
[00:06:53] Joe M.: Nobody was talking about it. But I, I realized I had that experience, like, oh, I've now seen conservation. [00:07:00] I don't wanna say crises, but conservation situations in my own, in my own field experience. Even though I was a kid and it took me a while to. Understand the context, what I was saying, because as I said, that was all by myself.
[00:07:13] Joe M.: I was a kid. There was no internet. I had no way to learn.
[00:07:16] María B.: In case you're wondering, bull frogs were introduced to Southern California in the 1940s, 1950s, with the intention of starting frog farms. Previously, the red-legged frog and the yellow legged frog that Joe mentioned were harvested by the [00:07:30] millions for the frog leg trade.
[00:07:32] María B.: Naturally, this decline due to over harvesting. Led to the need to farm frogs and to some people, introducing the bull frog seemed like a good idea for that. But the bull frog brought in a disease now known as chytridiomycosis that would ultimately impact other amphibian species in the area and around the world.
[00:07:55] María B.: But nobody knew this yet, Joe didn't know this either. Now, let's [00:08:00] jump ahead to Joe's first visit to Guatemala. And keep in mind that before Joe went there, many other herpetologists, like Jonathan Campbell had already described many species of Central American amphibians. So by the time that Joe went to Guatemala, he could have a pretty good idea of what was supposed to be there.
[00:08:18] María B.: What he was supposed to find. So let's find out what did Joe find or didn't.
[00:08:25] Joe M.: Jonathan Campbell was my master, my advisor for my master's degree. As I said, [00:08:30] I, I was very anxious to expand my horizons to include, uh, I wanted to know what tropical ecosystems were like just for my personal experience. And so part of the reason I, I, I decided to go to work with Jonathan Campbell for my master's degree was because of his very active field programming in Central America, Guatemala, primarily.
[00:08:52] Joe M.: And I thought, oh, maybe there's a, maybe this is my opportunity to get to the tropics. If I could go with Jonathan Campbell on one of his trips. [00:09:00] And it worked. He, my, during my first year, he made arrangements for me to go except I did not go with him, I went by myself, which in retrospect was not a good idea.
[00:09:08] Joe M.: But, um, uh, and it was on that trip in my, what I was trying to do was look at ecological distributions of reptiles and amphibians on a vertical transect of a slope of a mountain, the Sierra de las Minas. And then, uh, that didn't. It turns out that that part of the mountain was essentially inaccessible. It was too [00:09:30] steep.
[00:09:30] Joe M.: Nobody goes up there. Nobody goes up there. That's what all the locals told me. They said, you can't go up there. And oh, and then I tried. I went there, right? I can't, I can't get up there. Um, so I, uh, it, my, my trip turned more into, uh, looking at the relative abundance of species on a coffee plantation. A coffee finca.
[00:09:51] Joe M.: Because that was where I was based out of there and trying to get up the mountain from this coffee plantation. Uh, but anyway, in the process of doing that, I [00:10:00] discovered a little toad that I couldn't identify and, uh. Long story short, I, I, I found the, for the first time in my career, a species new to science.
[00:10:10] Joe M.: My, I just couldn't believe it. I couldn't believe that, that this was possible. I've read papers of people finding new species, and it seemed so exotic and so crazy. I couldn't believe that it just happened to me. I'm standing there holding this in my hand going, I have no idea what this is. I thought I knew everything here, and I, I don't know what [00:10:30] this is.
[00:10:31] Joe M.: Then when I got back and, uh, was looking at museum specimens, I realized like, oh yeah, this is, this is different. So in the process of naming that, I realized like, oh, I like taxonomy and that changed my direction. Taxonomy in the strictest sense is we have three different forms of life in front of us.
[00:10:52] Joe M.: They should have, they should all be recognized formally and they need three unique names. So. You formally write a [00:11:00] description proposing this as a species new to science, and then through a whole set of very Arkane, uh, rules of taxonomy that go back centuries, you formally apply a name to it. And so the toad that I found, uh, wound up with the name Incilius campbelli I named it honor of Jonathan Campbell because he was, um, raised in Guatemala his whole life and devoted his entire career to documenting the biodiversity.
[00:11:27] Joe M.: And conservation of reptiles and amphibians in Guatemala. [00:11:30] And he arranged for this life-changing experience for me. And so all that together, I, I decided to name the toad in honor of him. So for all eternity, we'll have Campbell's forest toad, uh, or Incilius campbelli on the planet. It's a beautiful toad too, not a cane toe.
[00:11:47] Joe M.: It's much prettier than a cane toad
[00:11:48] María B.: I agree on that.
[00:11:50] Joe M.: Do you know the frog? Do you happen to know that frog? Have you seen that toad?
[00:11:54] María B.: I've seen it. I think only in pictures, not not live.
[00:11:57] Joe M.: Okay. Yeah. Yeah.
[00:11:59] María B.: And you [00:12:00] mentioned before that when you found it and you were seeing something that you could not describe, you could not, you didn't know the name of it, you mentioned
[00:12:09] María B.: I thought I knew everything that was here. How was this in Guatemala then? You had lists from Campbell. I assume also David Wake and everybody that was there before. Were you finding everything they found or was the. Scenario looking differently? Is there something you couldn't find? How was it?
[00:12:27] Joe M.: Uh, so there, there was no, there still [00:12:30] really isn't a field guide to the reptiles and amphibians of Guatemala, but I did have some, uh, old checklists published in the, in the obscure primary literature. So I found all as I knew I was going on this trip, I needed to, I wanted to do my homework so that I knew what I was looking at when I got there. And then also I was at University of Texas at Arlington with the museum collections. So I was able to go and look at museum specimens of almost everything that was on my list.
[00:12:55] Joe M.: So I, I had a, I could physically look at it, but the toads were [00:13:00] easy. There should, according to all the experts, there should be two toads at that site. Cane toads and I think what I'll call a Gulf Coast toad, I'll call it that. And they were there. They were abundant, just like I expected all my homework expected that.
[00:13:15] Joe M.: And then I found this third one, uh, that I didn't expect, and that wound up being, being the new one. But the, um, other thing that struck me on that trip a little bit like my high school experience is that there were amphibians in my [00:13:30] list that I couldn't find. Uh, I, you know, I talked to people, you know, what are the secrets?
[00:13:35] Joe M.: What do I need to do? And, you know, I learned, okay, in the tropics in, uh, uh, you, you find a stream and you walk up the stream in the middle of the stream at night with your flashlight, and you look on the leaves and the rocks or in the stream. That's how you find things. I was like, oh, okay, you don't do that in San Diego.
[00:13:52] Joe M.: That's new to me. Okay? And so I did that and, and they said, oh, they're right. My flashlight, I see these things. It was like, you're, I never would've seen these [00:14:00] otherwise. But at the end of the summer, there were species that I looked at other collections from the region. You can get a sense of how common something is from museum collections if they had a lot of them.
[00:14:12] Joe M.: And I was looking at some stream site frogs, for example, the genus Craugastor. And they, they should have been common at my site and they weren't. Some of them I found zero, uh. One species, i, I saw one. And so it was like high school all over again. [00:14:30] It's like, I can't find these, I can't find these. Uh, and my immediate assumption was like, well, this was my first time in the tropics.
[00:14:37] Joe M.: It didn't grow up there. Um, uh, obviously I don't know what I'm doing. I immediate, immediately assumed that my failure to find some species that I expected to be common. I assumed that that was my, my fault, that I just. Wasn't doing something right. And Jonathan Campbell, in a very good natured way, actually was kind of making fun of me a little bit.[00:15:00]
[00:15:00] Joe M.: He, you know, he became aware, he was looking at the collection. He goes, gee, Mendelsohn, there should have been one of those on every other rock along the stream. How, how did you, were you looking? I was like, yes. I was trying to look, you know, he's like, well, you missed them. Right. It never occurred to anybody that they simply weren't there.
[00:15:20] Joe M.: The only parsimonious explanation was that I, I suck at finding frogs in rainforest. You know?
[00:15:28] María B.: I know the feeling. [00:15:30]
[00:15:30] Joe M.: Yeah. It literally never occurred to anyone that they simply were gone. They should have been common. They used to be common. That was in 1989, so in 1989, there were species in Guatemala that should have been common, that were not.
[00:15:50] Joe M.: I went back to Guatemala a few different times. This time, usually with Jonathan Campbell at this time, and, and we were both commenting, it's like, wow, the amphibians [00:16:00] just we're not finding, you know, at, at the end of the summer we would look at, at our notes and it was like we just did not find very many.
[00:16:06] Joe M.: And the site that, the site in Guatemala that really got our attention. Was a big wetland next to the most famous, um, bio preserve in Guatemala. The, the Biotopo Mario Dary, just outside of that, so technically not protected is a big, uh, wetland that from the notes and from John Campbell's personal experience, the, there were a couple of species of frogs [00:16:30] there that were abundant, just absolutely abundant, and they were gone.
[00:16:37] Joe M.: I asked Jon Campbell and he is like, what do you think happened? Why, why? Why are they gone? We're looking at the wetland. It's still there. Jonathan, he didn't have the answer and bet in our conversation. He, he didn't know why they were gone. Nobody knew. And in our conversations, we were doing what we would later learn everyone across the world was doing going, gee, frogs at our site just disappeared. [00:17:00] Hm, maybe it must have been a couple of dry years and just some bad luck. Well, next year we'll be fine. And honestly, didn't really think much of it. Just assumed that herpetologists know that sometimes animals are findable and sometimes they're just not.
[00:17:15] Joe M.: And you learn to just accept that as normal because they can go underground for long periods of time. We know that. And when you don't find them, nobody panics.
[00:17:24] María B.: While the idea of national parks or protected areas was already around since the late [00:17:30] 1800s, it only boomed until like 1980s, 1990s, especially after the 1992 Rio Earth Summit and the resulting convention on biological diversity.
[00:17:40] María B.: So one of the questions was, why are all the frogs disappearing even inside protected areas? What scientists were starting to understand was that protected areas might just not be enough to shield some sensitive species from threats like diseases or climate change. [00:18:00]
[00:18:01] Joe M.: And that was the now breaking away from our personal experience.
[00:18:05] Joe M.: This is what came to a head in the, in the famous story at the World Congress of Herpetology in, uh, in Canterbury in England. I was not at that conference, but it was at that conference where. All those conversations, like I just mentioned, uh, people started having them and started realizing, it was like, wait a minute.
[00:18:25] Joe M.: At your field site, you've had a, a two common species just suddenly [00:18:30] disappear and you're in Australia. Wait at your field site In Costa Rica, that happened. Wait. Oh, and at your field site in Colorado, the toads that were abundant just suddenly all were gone the next year. And, and that's where, uh, George Rabb and David Wake started connecting the dots and saying, we have too many people, very good field herpetologists, too many places around the world telling the same story, and then they're all defaulting to, it must just be a bad year.
[00:18:59] Joe M.: [00:19:00] Oh, it's been a little dry lately. Or, oh, something they just decided not to breed this year. Just dismissing it as. Normal slash bad luck. That's what everyone kind of was doing. Nobody honestly thought they were gone. Nobody even mentioned the word disease. That's what was happening in 1989, 1991. This is around the era of the World Congress.
[00:19:24] Joe M.: Um, anecdotally, another interesting thing happened while I [00:19:30] was looking through my notes from my first trip to Guatemala in 1989. Realizing that there were things that should be common that weren't there. Just down the hall. Jonathan Campbell and Eric Smith were describing a new species of Ptychohyla for Guatemala, uh, a a little stream- breeding tree frog.
[00:19:49] Joe M.: And I wasn't involved with it at all, but I was interested in paying attention, and I specifically remember them complaining. It's like they had the tadpole for this frog. [00:20:00] It's typical when you describe a new species of frog to also describe the tadpole. And in describing a tadpole, the details of the mouth parts, which is a very complex organ in, in tadpoles, um, is crucial.
[00:20:13] Joe M.: And I remember them complaining that all the tadpoles that they had for this species, the mouth parts were all deformed or just missing, just gone. And that frustrated them 'cause their job is to describe the mouth parts, but their specimens did not have the mouth parts. [00:20:30] In retrospect, it's obvious those tadpoles were infected with chytrid.
[00:20:34] Joe M.: chytrid eliminates the mouth parts of tadpoles, so they weren't, they were being taxonomists, they weren't being conservationists. They had no idea what was wrong with these specimens. They assumed that the specimen had been damaged in transit and that the mouth parts fell out or some ridiculous thing because
[00:20:54] Joe M.: they had no context. They had no reason to think that there was this unknown fungal pathogen that would affect the [00:21:00] mouth parts of tadpoles, and they're sitting there looking at it and just being frustrated 'cause they couldn't do their job. That happened at the, that was the same week. So these things are happening, these dots are there, but no one was connecting.
[00:21:14] Joe M.: No one was connecting them. That started to happen at that World Congress.
[00:21:18] María B.: If this is all new to you, let me catch you up. The chytrid fungus that infects amphibians is a skin disease. Unlike our skin, which is several layers of cells deep, [00:21:30] amphibian skin is very thin, and amphibians primarily breathe through their skin, as well as balancing many other important metabolic processes.
[00:21:39] María B.: In adult frogs and toads, for example, their extremities have a lot of keratin. In the tadpoles, the keratin is in their mouth parts like Joe was telling us. Now, in the tadpoles who mainly feed on algae, the keratin forms these tiny teeth-like structures in their mouth parts, which they use to scrape the algae off [00:22:00] rocks.
[00:22:01] María B.: Now guess who needs to eat keratin? The chytrid fungus. So in the tadpoles, it directly interferes with their feeding; in the adults, it is basically suffocating them. Like Joe said, people began connecting some dots in the first world Congress of Herpetology in 1989, patterns were emerging, questions were being asked, but it would take another 10 years to even learn what disease we were even dealing [00:22:30] with.
[00:22:31] María B.: So what happened in those 10 years?
[00:22:35] Joe M.: That was a really interesting span of time. Really, really interesting span of time. The story went from people like me realizing they couldn't find certain things and, and not panicking, just dismissing it as bad luck essentially, or, or wheather anomalies, no one was saying climate change, and importantly, no one was saying they were [00:23:00] actually gone.
[00:23:01] Joe M.: All they were saying is that I can't find them. The idea that they were actually gone was beyond anyone's comprehension, right? Uh, a, a crucial paper. The famous, uh, Costa Rican golden Toad, uh, was being very carefully monitored, and then it disappeared right in front of everybody, although nobody found a dead body.
[00:23:25] Joe M.: Marty Crump published a paper. So here we have a [00:23:30] very, very accomplished frog ecologist. Who had all of the data to suggest that this population completely disappeared in a very short amount of time. That still could not bring herself to say that they were actually gone. She had to, there was a, a, a qualifying phrase in the title of the paper, 'cause still in the back of everyone's head is no, they, they, they can't be gone.
[00:23:55] Joe M.: That doesn't happen. They must just still be underground for some reason. We don't [00:24:00] understand. That's the mystery. Why are they still underground and, and everyone was just denying what their eyes were, telling them. Their eyes and their experience and their notes and their data sets were telling them that they were gone and no one could wrap their head around that.
[00:24:17] Joe M.: And then a few years into this, as it became apparent that no, they really do seem to be gone. Then a big schism erupted, and this was very, very unhelpful. [00:24:30] And then eventually it became obvious that these declines were real. They were actually real and, and they weren't happening everywhere, but where they were happening, they were real.
[00:24:44] Joe M.: And just about, just about everybody finally realized it's like, yeah, this is real. And then the whole shift became to what's causing it. That was a whole other, now people are no longer dismissive. Now people are in panic mode. This would've [00:25:00] been early nineties, 92, 93, something like that. And it became the search for the cause.
[00:25:08] Joe M.: And then someone else had another hypothesis and another hypothesis. And very quietly, a couple of people start saying, this looks like a disease. Couple people in Australia and notably Karen lips working in Costa Rica,
[00:25:26] María B.: and back then there was not such a like fast [00:25:30] tools to, to discard those options right away.
[00:25:32] María B.: Right. How when they thought that this has to be a pathogen, what was available to, to find proof for it,
[00:25:39] Joe M.: it was discovered by two really good pathologists, Don Nichols and Alan PEs. And they are working with some animals from the National Zoo in the United States. They did something really remarkable.
[00:25:59] Joe M.: They, [00:26:00] they looked through these dead bodies, and this is all histological sections. So to answer your question, how do you do this? You do it with old fashioned histological sections and you go through in the microscope, slide by slide, looking for. It's like, ah, you know, pathologic pathologists know what to look for.
[00:26:14] Joe M.: Okay, we have edema. Okay, we have burst blood cells here. You know, they, they, and they go through and they saw all kinds of symptoms, mostly in the skin. But no, they, they couldn't find any evidence of a pathogen because they were looking for pathogens that they, that they were trained to [00:26:30] look for. And then I wasn't there, so I don't know what happened, but there was this moment, figuratively speaking, where one of them went, wait a minute, what's that?
[00:26:41] Joe M.: There was one little thing on that slide that didn't look familiar. They didn't know what it was, but they knew it wasn't frog tissue, but it wasn't a bacteria. They didn't know what it was. It turned out to be chytrid, and then there's a whole long story for them to figure out that this was a chytrid fungus . Cause chytrid fungi, were not known to [00:27:00] be parasitic or infectious on anything.
[00:27:03] Joe M.: There's a poorly known group of fungi that nobody paid attention to that are mostly decomposers in the leaf litter. Why would a, why would a vertebrate pathologist know that these things exist? There's no reason for them to know that these exist, but the brilliance they get credit for is noticing something that didn't look quite right.
[00:27:22] Joe M.: And that wound up being something that nobody ever expected. A pathogenic chytrid fungus, who knew? And [00:27:30] they quickly identified the only chytrid fungus expert in the world and, and found her, and she looked at that and said, yeah, this is a chytrid fungus. What's it doing in a frog tissue?
[00:27:45] María B.: You mean long Longcore was her last name?,
[00:27:46] Joe M.: yeah.
[00:27:47] Joe M.: Yeah. Sorry. No, Joyce Longcore. I, I didn't mention her name. That was rude. Yeah. Joyce Longcore, of course. Yeah.
[00:27:52] María B.: You mentioned before that while everybody was discussing at this first world herpetology Congress. [00:28:00] That they were not finding frogs anymore. There was not a lot of finding dead frogs either. Yeah.
[00:28:06] María B.: So that was also another challenge to get samples for this pathologists, I guess, if people were just not finding anything at all. Not even sickly frogs or dead frogs.
[00:28:16] Joe M.: Yeah. That was a big problem for the people that were arguing that this was a disease. So they had the problem that they couldn't put a name on it.
[00:28:23] Joe M.: They didn't know they did, couldn't suggest a pathogen. The other problem was. They had no [00:28:30] observations of sick frogs. They had no observations of dead frogs. They had observations of a healthy community, and then a community with no frogs missing were the key observations that would help you suggest it was a disease.
[00:28:42] Joe M.: And that's, that was a big part of the criticism that was levied at them. They're going, if this is disease and animals are dying, where are the dying animals? And that was a valid criticism, and it was once again, going to Karen Lips. It was Karen Lips that, um, found the dead and dying [00:29:00] animals. That was, uh, personally for me, that was a big breakthrough.
[00:29:03] Joe M.: Karen Lips and I became friends. We were about the same age we were in competing graduate program. She worked with Jay Savage. I worked with Bill Duellman, and now I'm not at with Campbell in Arlington, Texas anymore. I'm in my PhD at Kansas, mostly still working in Guatemala and, and now Mexico a lot as well.
[00:29:20] Joe M.: She was working on, I was doing taxonomy and systematics, she was doing ecology in Costa Rica and eventually Panama. And we just became friends and talking [00:29:30] about it. And this is when she was reporting these, these declines and suggesting that these were diseases. I believed her. I thought everything she was saying made sense and it was her that put the bug in my head that said, she said, you know.
[00:29:47] Joe M.: The fact that you can't find very many frogs in Guatemala and now in Mexico, um, may, that might not be your fault, Joe. She goes, has it ever occurred to you that these declines that I'm seeing in real time [00:30:00] in Costa Rica happened there before you got there? And so what you're looking at is a post decline site. That had never occurred to me.
[00:30:11] Joe M.: It was also a huge relief and it was like, oh, maybe this isn't my fault. You know, I was still stuck on that. Um, and in retrospect, uh, she was absolutely right. What had happened is the chytrid moved through Mexico and Guatemala and, and Honduras and place, you know, [00:30:30] and it just simply never occurred to anyone that, A, they really are gone.
[00:30:34] Joe M.: And B, they disappeared a few years ago and nobody noticed. What Karen was doing was starting in her head. I can, in retrospect, I can see she's starting to put together the map that really made her famous, that spatial-temporal spread. She's starting to realize, she goes, it seems to be moving through Costa Rica in a very consistent fashion and moving towards Panama, [00:31:00] and we have these very mysterious die-offs that were seen in the United States in the seventies, like in Colorado that no one could really explain. And she started to realize, she goes, this looks like a fluid map that went through Mexico, Northern Mexico in the seventies, Southern Mexico in the eighties, Guatemala in the eighties. In the early eighties, and is now in Costa Rica around now in the mid eighties. That's the golden toad and her field.
[00:31:27] Joe M.: The spatial temporal spread I could sell was starting to [00:31:30] gel in her mind. But the momentum was there that. In the, in the amphibian community that this is a disease, and the evidence kept becoming more and more clear that this disease is doing this by itself. There were a few very vocal objectors, but the, the community was essentially drifting that way.
[00:31:49] Joe M.: And then in my mind, the key observation was a really, really prescient study that Karen Lips did. She wanted to [00:32:00] test her spatial temporal hypothesis because people were arguing against her and she thought she was right. I thought she was right. A lot of people thought she was right, but everyone including her would, would, would admit that, that the evidence wasn't very solid.
[00:32:15] Joe M.: So she goes, okay, I'm just gonna do this. She got a big grant. She picked a study site in Panama that was further down the chain, away from the declines. She went there and she [00:32:30] verified that this place is healthy, this place is intact. All the frogs that we expect to be here are here and they're abundant.
[00:32:37] Joe M.: And she goes, my prediction is that the Chytrid Fungus is not here right now. And so she did all the testing and about this time we had a PCR test rather than histological sections, which made things much, much easier, but very expensive, I should say, at that time. She basically said, she goes, I'm gonna sit [00:33:00] here and survey this site for as long as it takes to test the hypothesis that this is a healthy community that is, has zero incidence of chytrid.
[00:33:10] Joe M.: And she goes, if my spatial temporal hypothesis is correct, one day I'm gonna find a dead frog and it's gonna have chytrid in it, and then, chytrid's gonna explode and this place will decline. Like all of those other study sites all the way back up in New Mexico. I think it took seven years. I think she and her [00:33:30] graduate students worked at that site for seven years demonstrating, yes, amphibian populations fluctuate.
[00:33:36] Joe M.: This is her way of saying yes, I'm aware that they fluctuate. I have the data to show that they fluctuate at this site. I also have the data to show that while this is happening, there is no chytrid fungus at this site. And then she had the data that when the chytrid appeared also, I should say that during those seven years she had.
[00:33:55] Joe M.: Zero observations of dead frogs. Right. You don't find dead frogs in the [00:34:00] tropics because they decompose so quickly under those circumstances. Yeah. So it was Karen Lips that stumbled across the dead and dying frogs and sent them to Alan Pessier and Don Nichols and they went, yeah. These have that same my mystery thing inside them that we saw from the dead frogs, from the National Zoo.
[00:34:22] Joe M.: And at the same time. Herpetologist in California named Sam Sweet, somehow caught wind that they were, [00:34:30] that these guys were looking at weird frog deaths. And he had some toads die in his lab for a reason he could not figure out why. And he, he, he's a really good herpetologist and this didn't make sense to him.
[00:34:44] Joe M.: So he sent them out and they said, wow. These frogs from California have this same weird little thing inside them. So it's now in some frogs from Australia. It's now in this dead dart frog from the National Zoo. It's now in these frogs from Sam Sweet's [00:35:00] Lab in California. And then not too long later, Karen Lips founded in some dying frogs in Costa Rica.
[00:35:07] Joe M.: I distinctly remember sitting in this chair in this office with that phone getting the call. In 2003, I think maybe 2004 saying, Joe, it's Karen. It happened. My team found a couple of dead frogs last night and we sent them off for PCR and she called me back a couple weeks later. She goes, [00:35:30] and they had chytrid.
[00:35:30] Joe M.: This is the first dead frogs we've seen. This is the first report of chytrid at our site. She goes, this place is about to crash right in front of us. And then she documented the entire crash. That was the data set. It was the definitive data set, a turning point in getting everyone on the same page in my mind.
[00:35:50] Joe M.: And that led to the Atlanta meeting.
[00:35:57] María B.: In the next episode, we'll follow what happened [00:36:00] when scientists finally agreed that something was happening, and they came together from all corners of the world to draft the first ever amphibian conservation action plan and how the idea for Amphibian Ark. Took shape.
[00:36:16] María B.: This podcast is brought to you by Amphibian Ark, hosted by me Maria Braeuner with original music by Pablo Bolaños of Biota Specimens and made possible by supporters like yourself, who believe amphibians are [00:36:30] worth saving. You can help us bring this important message to more people by subscribing wherever you listen to podcasts.
[00:36:37] María B.: Like, rate, review and share this episode with your friends and family. And if you'd like to be a part of the solution, you can support Amphibian Ark's work directly. Find the link in the show notes. All donations help secure a future for the species that are most at risk. Together we can continue rescuing amphibians in crisis.
[00:36:59] María B.: Until next time.
About the podcast
Amphibian Rescue is produced and hosted by María Braeuner, with original music by Pablo Bolaños | Biota Specimens.
Episodes are reviewed and fact-checked by the Amphibian Ark team of experts: Luis Carrillo, Devin Edmonds, Renata Ibelli Vaz, Jonathan Wilcken, Cybele Lisboa, Elizabeth Townsend, María José Chang, and Beatriz Velásquez.
Trailer video footage by © Jaime Culebras; additional clips via © Canva.com by Leo Lee, Black Box, Atelopus | Getty Images, Daniel Bahrmann | Pixabay.
Cover image © Jaime Culebras
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Together, we can continue rescuing amphibians in crisis.
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