Hellbenders

Alex Re (00:00): Hello, welcome to On Wildlife. I'm your host Alex Re. On this podcast, we bring the wild to you. We take you on a journey into the life of a different animal every week, and I guarantee you, you're going to come out of here knowing more about your favorite animal than you did before. The animal that we're going to be talking about today is a large amphibian found in fresh water. They have some pretty cool adaptations that help them survive in the wild, and I can't wait for you to hear about them, but they're also in need of our help because their populations are declining. Luckily, our guest, Nick Burgmeier, the Extension Wildlife specialist at Purdue University, knows all about them and how we can help. So get ready to hop into some rivers and streams because we're talking about hellbenders.

(01:05): Hellbenders are a species of salamander that live in the rivers and streams of North America, and these aren't your average small salamanders that you find hiding under a rock on land. They're fully aquatic so they don't need to leave the water. This is abnormal because salamanders are amphibians, which usually means they spend part of their lives in the water and part of their lives out of the water. They're also the largest salamander in North America. They can grow to be over two feet long and weigh around five pounds and people don't just call them hellbenders. They're also called all kinds of different names like snot otters and old lasagna sides. We'll talk about why they're called that later on in the episode. But first, let me introduce our guest, Nick Burgmeier, who studies hellbenders at Purdue University. Let's hear about why he decided to start studying these amazing creatures.

Nick Burgmeier (02:01): I've been interested in herbs and animals in general from pretty much most of my life. When I was a small child, I was up running around chasing around bugs and snakes and scaring my parents, but I didn't grow up in an area with hellbender. So hellbender specifically. I had the opportunity during a summer job when I was in college to go out with the state herpetologist in Indiana and do some surveys and I mean it was just a couple of days, but that was really fun, enjoyed it. And then the following summer, I ended up working for the state herpetologist and so I got to do many more help vendor surveys and that really got my interest up. And then right at the end of that job, a grad school position came open working with hellbenders in Indiana. So I applied and ended up getting that and it's just gone from there.

Alex Re (02:55): hellbenders are so interesting. No wonder Nick enjoys working with them. For instance, they have an extremely unique anatomy that helps 'em survive in their environment.

Nick Burgmeier (03:05): So health vendors, I mean they are a fully aquatic species, so most of their adaptations are for a life in the water. I mean, one of the main things you might notice on hell vendors is that even though they live underwater, they don't have gills, at least the hell vendors that most people see. So they hatch when they hatch, they do have gills, but they lose those after about a year and a half to two years. And then at that point it just looks like a little mini bender, a little mini adult hell bender, and they actually breathe through their skin. So they have very highly permeable, very vascular skin, and so they just absorb the oxygen into their body and into their bloodstream. And one of the sort of defining features of hell vendors, they have these big folds of skin along the sides of their body and that's really just extra skin to increase the surface area to help them absorb more oxygen.

(04:07): And that's also how they get one of their other names, the old lasagna sides, which is kind of a fun name that they're called in some places. And one of the reasons hell vendors are typically associated with sort of high water quality areas is because they do, since they don't have gills, they do have to absorb that oxygen through their skin and they really need those high water quality areas. That's generally where high oxygen levels are. Usually poor water quality is associated with low oxygen levels and health vendors just can't handle that. They don't have really an alternate way to absorb oxygen like mud puppies for example, have gills. They can live in sort of lower quality areas, ponds and lakes and ditches, but the hellbenders can't do that. They need that high water quality.

Alex Re (04:58): And this is something that we're going to talk more about later on in the episode because the quality of fresh water is going down due to a bunch of different factors caused by humans and the permeability of their skin makes them extremely vulnerable to that.

Nick Burgmeier (05:14): This goes for most amphibians, especially aquatic amphibians. Basically anything that gets in the water, whether it's high oxygen content or pollutants, pesticides or salt, anything like that that gets in the water motor oil, that stuff can just be absorbed right into their skin so they really have a hard time. That's one of the reasons why we generally consider them the sort of canary in the coal mine because they're one of the species that disappears first in the acquired ecosystem,

Alex Re (05:44): As Nick mentioned, these are completely aquatic animals. This makes their methods of navigating through the environment a little different than those of us that live on land.

Nick Burgmeier (05:54): So if you see a hell blend, you might notice these things have tiny little eyes so that they can see, but they don't see very well. So most of their navigation, most of their ability to find prey is based on sense and touch. And also they have a lateral line system that's sort of similar to some fish and that allows them to, they can sense movement in the water, they can sense vibrations and pressure changes. So if something moves nearby, even if it can't see it or even necessarily smell it, it might feel it move, then it can go over that direction or away. If it happens to be a predator,

Alex Re (06:30): It's really amazing that they're able to sense changes in water pressure. I was also interested to know if hellbenders are social animals.

Nick Burgmeier (06:39): hellbenders in the wild are not very social animals. We don't usually find them together outside of the breeding season. They are usually pretty territorial, especially during the breeding season. Males will defend potential nest rocks. Even females will fight with each other. But during the breeding season we do, they will come together, I mean obviously to breed and sometimes you see these big congregations which usually amounts to a male under a rock, and then there'll be sometimes multiple females going to the rock and maybe even a sneaker male trying to get in there and fertilize some eggs. But they are territorial. We see hellbenders with big bite marks on 'em. They occasionally rip off each other's limbs. They can get pretty rough out there. There haven't been a lot of studies on specific hellbender social interactions. I know there was one that tried to look at in captivity that tried to look at some courtship behavior and they did seem to do some males and females did some circling behavior, which is common in other salamanders and some tail swishing, but it wasn't real definitive on whether or not it ever led to anything or if it was just some minor interaction in captivity.

(08:01): It is a little different. We rear juvenile hell vendors at Purdue and in some of the zoos and for whatever reason those things congregate, even if they have options, multiple shelter options, you will tend to find them congregated in one or two and we don't really know why because they don't do that once we release 'em into the wild. They don't do that. We rarely find 'em together in the wild, but in captivity they seem to pick a shelter and then they all go to that one. But even then, once they do start to get a little older, they do fight a little bit and we do get some juveniles that have injuries and some actually will occasionally fight each other's feet off again in captivity.

Alex Re (08:45): And oftentimes you can see an animal's behavior change when it's in captivity compared to when it's in the wild. I would imagine it's hard to observe these animals in the, because they live in rivers and streams and they're also mainly nocturnal.

Nick Burgmeier (09:00): So they're just a hard species to get a lot of behavioral stuff and they spend so much of their time under rocks that you just can't see much. I mean they don't come out from under their rock very much. So they're tough to work with.

Alex Re (09:18): Now let's go back to talking about some issues that they're facing right after the break. The science word that I want to tell you about today is avo vi vipers. If an animal is avo vi vipers, that means that they store fertilized eggs in their body and don't lay them. The babies hatch while still in the female's body and then they're released once they hatch. Some species of snakes and sharks are avo vivi. Okay, we're back. So what's hurting hellbenders?

Nick Burgmeier (10:09): Well, so big picture climate change is likely to be a significant issue with PE benders. It's a little hard to predict exactly how it's going to affect them, but warming temperatures, we expect warming, warming water temperatures which would then subsequently lead to a decrease in dissolved oxygen in the water and also changes in the surrounding landscape. So we're not sure exactly, but I do suspect especially some of the populations that are already sort of hanging on or that are in areas that are a little warmer already, those populations might end up blinking out I guess on a more local or regional scale. The major issue is sort of just general forest loss once you cut down all the trees, and we have seen this in a few studies that they do tend to be highly correlated with forest cover in the landscape and landscape. Once you lose that forest cover combined with a lot of agricultural runoff or urban runoff, especially in the Midwest, we suspect that's led to the decline throughout much of their range.

Alex Re (11:18): I feel like not many people think about how deforestation affects aquatic animals. We tend to think about how it impacts animals that live in trees, but it can be a huge problem for freshwater ecosystems as well. And hellbenders are important for a healthy ecosystem too.

Nick Burgmeier (11:35): So one of the unfortunate things about hellbenders is that people didn't really study them a lot before they declined. There were a few people that would go out and do a mess with 'em, but for the most part they didn't get much attention until they had already mostly disappeared or at least heavily declined. In a lot of areas. We generally think of hell vendors as being one of the top predators in whatever stream they're in. Certainly some of the smaller streams, but even in some of the bigger streams, they are likely one of the top predators. They're primarily crayfish, so they're kind of a crayfish specialist. They'll lead other things too, but some studies have shown 80 plus percent of their diet is crayfish. So we hypothesize that they probably do have some effect on regulating crayfish populations, but again, nobody paid attention to that until after they had declined. But that's kind of a weird thing to talk to the general public about like, oh, well health vendors might regulate crayfish populations. The importance of crayfish is they tend to be voracious eaters of everything they can fit in their mouths. And the idea is that if the health vendors disappear, the crate fish population shoot up and they eat all the little macro invertebrates that are on the bottom of the stream that the fish eat that everything else eats that it could throw those lower trophic levels out of whack. But that's just sort of the hypothesis because nobody's ever had the opportunity to say, to see a pre slash post decline stream.

Alex Re (13:13): It's unfortunate that we didn't get a chance to study them until after they started to decline, but it's thought that if they disappear, it could have some negative implications on the food web

Nick Burgmeier (13:24): For something that's maybe slightly more, maybe the general population, the general public might see as more of a benefit. As we talked a little bit about earlier, they are that sort of canary in the coal mine and most people do, or at least people that live near rivers or like to drink water, they do prefer clean water. And you do know that when your health vendors start disappearing, that lets you know that something is wrong with your system. We don't know exactly what that is, but it could be that there's chemicals in the water or it's just a general decrease in water quality.

Alex Re (14:03): So for that reason we would call hellbenders an indicator species. Luckily Purdue is working on helping hellbenders right now.

Nick Burgmeier (14:11): In the mid two thousands, Indiana Department of Natural Resources approached Purdue to look at our remaining hellbender populations in Indiana and we knew when they approached us that there was pretty much just one stream left in Indiana that still had hell vendors. They used to be in most of the streams in the central slash eastern. Let's see, lemme think how to word this. Hell vendors used in Indiana, hell vendors used to be found and most of the Ohio River tributaries from about Crawford County, which is the south central part of the state all the way east up towards the border of Ohio. So they're in most of those streams, but by the mid two thousands they're pretty much just in one river, the Blue River in southern Indiana. And so the D n R asked us, Hey, can you try to figure out what's wrong with these things?

(15:05): Essentially how many we have left? So we did a lot of population surveys, we looked at their genetics, we looked at various health indicators like sperm quality, and we looked at their blood to see if they have any diseases and basically everything came back great, they're fine. They don't have any problems individually and the habitat quality was good there, the habitat was there. So in Indiana we kind of think that whatever happened happened in the past and it's since improved. But health vendors got to a point where they just couldn't recover. So that sort of led into the next phase of our work, which was figuring out what do we need to do to bring these back. We did some modeling to see how many hell vendors we would have to put back and how well they would need to survive. And at that point in about 2017 was our first release of hell vendors.

(16:02): So since 2017 we've been actively releasing juvenile hellbenders back into the Blue River at a handful of preselected sites. And I should mention that the hellbenders we release come from at the original couple batches came from eggs we collected in the Blue River, but it's very hard to find eggs in Indiana. So we've since been going to Ohio and Kentucky to collect eggs from a couple of streams they have that still have good populations. And we realized in captivity for about three and a half to four and a half years and then we release those back in the wild.

Alex Re (16:38): That's really great. And getting eggs from different populations can help to increase genetic diversity.

Nick Burgmeier (16:44): One of the things we looked at, we looked at the genetics of our population and we didn't see any signs of inbreeding, but those animals are so old and it takes 'em so long to mature, we might not see signs of inbreeding until farther down the road. So bringing in this stock from outside of Indiana could definitely help increase genetic diversity. And we also were able, we actually did genetics throughout the range of hell vendors to see which populations were suitable and Ohio and Kentucky, those were suitable matches for our population. But unfortunately the places that would be the best to get other hell vendors from, which would be in the Appalachian Mountains, they still have some of those places still have great hell vendor populations. Those were not very good matches. They seemed to be genetically distinct from the Ohio River hell vendors and so we couldn't get those. But Kentucky and Ohio still has some good stuff, so we get our eggs from them.

Alex Re (17:44): But Purdue isn't the only institution working to help hellbenders.

Nick Burgmeier (17:49): So in Indiana we have what we call the Indiana Hellbender Partnership, A love. We talk a lot about Purdue and the D n r, but we have multiple zoos. We have Fort Wayne Children's Zoo and Indianapolis Zoo, mere Park Zoo. They help rear our hell vendors in captivity. Colombian Park Zoo, which is a little zoo up near Purdue, they do a lot of outreach and education, but it's not just zoos even. We also work with the Indiana Department of Environmental Managements. We work with US Fish Wildlife Service, we work with local soil water conservation districts and we even work with lots of landowners. I mean it's important for this kind of work that is directly, it's visible to the surrounding community. We drive our Purdue trucks all over the place and they see us. It's important to get that landowner. So we have landowners that they're happy to let us use their property and they come to our releases and they've really bought into what we do. So we have this big group of partners that really make this happen. It wouldn't be possible if it was just Purdue and the scale is too large for Purdue or even just Purdue and the D n R to accomplish this. So

Alex Re (19:01): That just goes to show how it takes the collaboration of a whole bunch of people to conserve and revitalize a population. So what can the average person do to help hellbenders?

Nick Burgmeier (19:13): For people that don't live directly next to Hellbender habitats, but maybe live in an area, like we mentioned, you cut down your forest over here. It's stuff drains. So for people that don't live next to Hellbender habitats that do maybe live in areas that drain to a stream that contains hellbenders, it's important to remember that that water does run off somewhere and maybe you're in town and you're thinking, well, what I do in town doesn't affect hellbender. But if there's storm drains there, in most places, storm drains do directly run straight to a stream. Most of them are not treated. And so we encourage people to obviously don't pour things down storm drains, but if you're spraying pesticides in your lawn, be aware of how that runs off and followed in directions because some people think more pesticides the better and they are formulated to work on a very, what they say on that label, it should work.

(20:10): So we encourage people to follow the label on their pesticides. Don't pour stuff down the storm drains. Maintain your vehicles. People don't think about that. But if your car is leaking oil that runs into the storm drain runs into the river, the fish the hellbenders. It's bad for everybody. Another thing that people really don't think about are pharmaceuticals. Some people just, they don't know how to dispose of those. So a lot of times they just end up going down the toilets. There are proper ways to dispose of pharmaceuticals and it varies depending on where you are, but you can usually call your local pharmacy and they'll be able to direct where you need to dispose of those. For people that don't live anywhere near hell, winter habitats, that's a little different. We still encourage them, obviously not to pour stuff down the drain, but it's harder for them.

(21:04): The main way would be to, you can donate to conservation organizations, zoos that have a hellbender program, things like the Nature Conservancy. I didn't mention them actually. We do work a lot with the Nature Conservancy. It's one of our partners. Anything like that, land trusts that buy land that might be in Habitat. If you're thinking that you'd like to have a place to donate. Land trusts are great because they go out and they try to buy those properties that come up for sale that are usually sensitive, maybe next to a sensitive resource, endangered plants, or right next to a river or something. But nice stuff. The Land Trust really try to keep the nice stuff nice.

Alex Re (21:43): So it really comes down to being aware of the fact that nothing you dispose of just disappears when you pour something down the drain or flush something down the toilet. It might be out of sight, out of mind for you, but it goes somewhere, maybe even your local streams or lakes. I'm so glad that Nick was able to come onto the show to talk about hellbenders. I learned so much about these amazing animals. Now if you want to help, hellbenders. You should definitely check out Help The Hellbender, which is a project organized by Purdue. You can also check out the Southeastern Hellbender Conservation Initiative and Hellbender Conservation Campaign. Thank you so much for coming on this adventure with me as we explored the World of hellbenders, you can find the sources that we used for this podcast and links to organizations that we reference at onwildlife.org. You can also email us with any questions at On Wildlife dot podcast@gmail.com, and you can follow us on Instagram at On Wildlife or on TikTok at wildlife. And don't forget to tune in next Wednesday for another awesome episode, and that's On Wildlife.

Jess Avellino (23:02): You've Been listening to On Wildlife with Alex Re. On Wildlife provides general educational information on various topics as a public service, which should not be construed as professional financial, real estate, tax, or legal advice. These are our personal opinions only. Please refer to our full disclaimer policy on our website for full details.