Master’s student and graduate teaching assistant Riley Rines spent the 2024 summer in the West Gulf Coastal Plain of Arkansas researching tricolored and Southeastern myotis bat roost selection for a project led by Professor Emma Willcox. For episode 37 of the Step Outside series, he shares his experience netting bats in bottomland hardwoods and the project’s goal. All bats in the video were handled under the proper permits. You can watch the full interview below or on our YouTube channel.

The below interview transcript has been lightly edited.

I asked you to come on here to talk about your project, which focuses on tricolored bats and Southeastern myotis in the West Gulf Coastal Plain of Arkansas. Could you tell me a little bit about that project?

The Southeastern myotis and the tricolored bat are both species of greatest conservation need, particularly in Arkansas. The tricolored bat is a species that was originally proposed for listing a couple of years ago. I think going on a year or two now. I don’t know how that is now with the current political environment, but, because of that, Arkansas Game and Fish wanted to gather more information on those species so that they can put that in their wildlife action plan for species recovery. Basically, they contracted us out, and they want us to come out there and find specifically what they’re using for summer roost because it’s a very critical time for the species. We’re having them come out of hibernation. They’re beginning to rear pups. They’re gathering energy and restoring their fat reserves to put towards winter hibernation. It’s a really crucial time in their life history, and because there’s such a knowledge gap within that area, they wanted us to fill in that gap, especially with how extensive the tricolored bat range is. They expand from Nova Scotia all the way down to Nicaragua and within that. There are variations in Nova Scotia. They’ve been seen roosting in lichens in South Carolina. They’ve seen them roosting in Spanish moss. What are they roosting in in southern Arkansas, which could be totally different than what they’ve seen them roost in the Ouachita Mountains of Arkansas. This is a lot more bottomland hardwoods, a lot more flooding. They could be selecting for stuff totally different than three hours north.

You talked about the tricolored bat and southeastern myotis. Is there a reason you’re looking at both species?

Partly because it’s so hard to capture tricolored bats. Since the introduction of white-nose in 2006, they’ve had a 90% decline in population. They’re just very hard to capture. We’ve already done our first field season, and we captured zero tricolored bats. To my knowledge, there were only four tricolored bats captured in bottomland hardwoods. Two of those they didn’t put transmitters on because they were juveniles, so it’s very hard to capture them. We didn’t capture any in our first field season. We were kind of looking at how can we at least make use of our time and provide Arkansas Game and Fish with something that we can utilize, and we added Southeastern myotis for this upcoming field season to further confirm and help visualize where they’re using and what they’re using. Their range is kind of restricted to the coastal plain of the United States and the Southeastern region, and what they’ve seen those guys roosting in is typically larger trees in diameter. Tupelo, cypress forest. We would assume that’s probably what they’re going to use again, being that this is such a similar terrain as previous studies, or ecological region, I should say. We kind of assume that, but it does help in these management areas, especially with how important the forestry industry is, to identify some of these trees in this area that they might be using because they could reuse those same roost trees the next year.

Have you seen any similarities between the two species?

Not necessarily from the literature that I’ve seen. There doesn’t seem to be a ton of literature so far on tricolored bats in bottomland areas, and the ones that I have seen, particularly in South Carolina, they did notice them using more cluttered forest with denser canopy cover, which is believed to be because of trying to reduce that ultraviolet light getting to them to help with thermal regulation and everything. The one similarity that we do see in a lot of bats is how close they roost to water. Usually, when bats come off their roost, they’ll go straight to the water, get a drink, and then start their foraging activities, or they might even use that as a corridor to get between where they like to forage. It is such a great place for invertebrates that they might be consuming. We know that tricolored bats eat a lot of macroinvertebrates that come from the water, like mayflies, so there’s some overlap in the use of those areas. As far as roost trees in particular, tricolored bats roost more so in the canopy. They can be in bark or in crevices of the tree, but they’re typically in the foliage. They can sometimes be seen a lot in dead leaf matter on live trees. I should add also that they also roost more individually, more solitary, where one roost tree might have 1 to 7 individuals, whereas they’ve seen colonies of Southeastern myotis with 300 bats. That’s one reason why the Southeastern myotis uses larger trees in diameter. Typically, you see them in trees with basal openings, and they’re using that cavity within the tree more so than the foliage.

Both of these species are Arkansas species of greatest conservation need, and you talked about how the tricolored bat has seen a steep decline since the fungal disease white-nose syndrome was introduced. If you were explaining to someone who had no idea about this research and why this is so important, what would you tell them?

Bats have a lot of ecosystem functions, but they can also help us economically. We see this with a paper, I believe, that was published here in the McCracken lab. Bats can help reduce tests for agricultural reasons. I think that figures like $28 billion in agricultural pest control, and all of our bats here in this region of North America are insectivores. They all can help consume those species, and that’s the main thing that people say. This is why bats matter, but they’re also ecosystem engineers, and we see this when they go into the cave systems. Other animals might be using the cave as a temporary area to shelter. The bats are going in and out continually dropping guano, and that provides cave-obligate species with things that they may need. It’s like that interface of bringing the outside world into the cave designs a whole or sets up the building blocks, I should say, of another ecosystem. So those are important reasons why we should care about bats. Pest control, ecosystem engineering the caves, and then if we were to look beyond the scale of Southeastern or North America, we could see bats doing seed dispersal. We could see bats doing pollination. They just have a lot to offer because they are so diverse. They’re the second most diverse group of species in the mammal world behind rodents. There’s a lot of things that they can offer us on that front.

For this study, about how many bats did you catch in Arkansas last year?

We got 250 bats this past summer for 36 nights. [It’s a] pretty good number with how many nights we actually netted. One night was crazy. We caught 35 Rafinesque’s big-eared bats. That just seemed like one after the other, and we were still catching them. We’re supposed to leave the nets up for five hours to stay within U.S. Fish and Wildlife regulations. You can net beyond that, but typically, five hours is what’s recommended, and we were trying to pull the net down, and we were still having them fly in. Based on the time of year, we must have put the net right under a roost tree, and the juveniles had just become volant, so we were catching a lot of those guys as well as their moms. That was pretty crazy. I contributed that to a lot of captures that we had overall. We also had a wide range of species diversity. We had Southeastern myotis, Seminole bats, red bats, evening bats, big brown bats, and Rafinesque’s big-eared bats. So just a little bit of everything except for tricolored bats, which is what we needed the most. That was a hard pill to swallow. I thought it was like a numbers game when I was seeing how many we were catching most nights, what we were averaging, and then it just never came.

Are you going back to that same area this summer?

Yes. I’ll be adding some new areas within the region like Felsenthal National Wildlife Refuge and a couple of different wildlife management areas, but we’ll be in that same ecological region, in the bottom and hardwood areas, seeing what we can hopefully net. We plan to net a few more nights. We’ve added a whole month to the project out there. Hopefully, that will produce something for us.

About how long would you say it takes for you to go through all the data that you collect?

With the data we collect, it doesn’t take too long because we’ve mostly just taken biometrics of the bats. Forearm length, weight, sex, reproductive status, wing damage, which is looking at, kind of like scar tissue and things like that on the wing membrane, which is more of a measure of white-nose syndrome, and seeing how damaged that wing is. Other than that, we’re not really taking too much more from the bats. If we can capture a tricolored bat or Southeastern myotis now, you put a transmitter on, track that for the life of the transmitter, which could be about a week, and then we would take, if we’re able to successfully find the roost tree, vegetation data of the roost tree and roost plot. Then, we would also do that at random so we can eliminate bias and get a broader perspective of everything statistically. That’s the plan if we were successful in capturing. At that point, it probably would take quite a minute to sift through all of that data and then also do the statistical aspect of it and everything, but just for the biometric part, it doesn’t take too long.

What is the terrain like for these areas that you go into?

We’re focusing on bottomland hardwoods, so it’s very swampy. There are tons of bugs. Sometimes there’s a hatch, and you have a bunch of mayflies over you. That’s okay if you’re okay with them getting in your mask and under your glasses or something like that. Typically, it’s just swarms of mosquitoes I feel like, which is a little bit less fun. I feel like we kind of just stayed in bug spray that whole summer. Some of the areas, typically not over creeks and streams that we netted, but if we were adjacent to, like an oxbow lake or something that was a little bit bigger, we’d see alligators, water moccasins. There are a lot of occupational hazards in the swamps, but it’s also just a very lively place, which kind of makes it worth it, because you are running across a lot of snakes. We saw a mud snake this past year. Then, we see tons of different frog species. Even though it’s a tough terrain and area to work in, if you get past the heat and the humidity and the bugs, then you’re able to see a lot of cool things happening at night when the sun goes down.

You mentioning all those bugs makes me think about that question about why bats are so important.

Funny you mention that. We caught a red bat, an eastern red bat, early on in the night just off her roost. She did not weigh much for a red bat. She weighed like eight grams, I think. Then we caught her one or two hours later, and she went from eight grams to 13 grams. That’s all just from consuming insects. She might have just consumed a really big beetle, but I mean, it could have been a ton of mosquitoes or mayflies or whatever. It may have been what she was pursuing that night.

That’s wild and a great example.

Yeah, they consume a ton. I can’t think of the number, but there are papers out there that have the metric tons that bats consume of insects, and it is really astonishing how much they do consume. I often think if bat numbers were at their historical level, what they should be, what they used to be, how much reduction in pesticides could we have? Maybe not be pesticide free, but how much more could we save on money not using pesticides, or how much can we help other ecosystems that pesticides affect by having that historical number? That’s always something I think about, and it just highlights the importance of protecting these species in these environments so that we can ultimately benefit for the greater good.

For this project specifically, did Arkansas approach you about the project, or were they seeking a research team to do it?

They were seeking a research team, to my knowledge of how it operates. Arkansas Game and Fish was given money by U.S. Fish and Wildlife to put it towards species of greatest conservation need. They put out a job posting sort of, and then professors and contractors bid on that. Emma [Willcox] bid on that and ended up getting it. Then, she goes and starts looking for a grad student to undertake that project, and that’s how I ended up getting to that position.

How did you get interested in this type of fieldwork?

Well, I never thought I would ever work with bats. I mean, it wasn’t something on my radar at all. I grew up hunting and fishing. I grew up watching Steve Irwin every morning. I knew that if I woke up at 7:00 in the morning I could watch Big Cat Diary, and then if I made it to 8:00 I could watch Steve Irwin. I was always interested in wildlife conservation and fisheries, but I didn’t know where exactly I wanted to go in that because it’s such a broad range, and I’ve done a lot of broad stuff in my time from fisheries to skunks to bats being here at UT. I just wound up in the local lab out of trying to get my foot in the door somewhere, and it just snowballed from there because you end up making all these connections and doing more bat stuff, and then you keep the connection. Next thing you know, you’re getting your master’s doing bat research, and it’s something you never thought you would be doing.

Speaking of those connections, after you get your master’s degree, do you have any plans for the future?

I graduate next year in December, which is kind of concerning with all the recent events that have been happening. There’s a little bit of fear because my original plan was to go into the biodiversity department to be a biodiversity biologist with the state or federal agency. Historically, that was seen as the position that you got, and you’re set for life. You’re in it. You’re safe, and now there’s a lot of uncertainty there. Now you have this flood of eligible people back in the job market. It’s kind of an uncertain time. I’m not really dwelling on it or looking too intently right now because of that reason. If everything works out, I can still go that path, but if I have to work a job here or there until I get there, that’s okay with me. It’s a great way to look at it in a more opportunistic kind of way. It’s a great way to travel and meet new people and maybe do new things and work with new species. So, we’ll see.

Yeah, I know what you mean. A lot can change in a year, and hopefully, it’s for the better.

Yeah, that’s what I’m hoping for, and I know that’s what a lot of my colleagues are hoping for. These jobs do matter, and they are important, and I think the American people really care about these jobs and want these jobs to succeed and do good things because it’s hard to separate the American mindset from nature. The American mindset kind of encompasses existing with nature, and we owe a lot to what we have now to that connection, that tie. I think it will get better in time.

I don’t want to say end it on a positive note because you’re right in saying that the job market is very uncertain right now. A lot of things are very uncertain right now, unfortunately. I’m trying to think of a way to [end].

I know. It’s a gloomy topic. You hear a lot of people talk about, in this field, eco-grief and the feeling that what you’re doing amounts to nothing. You’re not making any progress. Everything’s against you, and you just can’t get into that mindset because then those people do win. Then, nothing gets done. It’s hard to not get into that mindset, but you just have to keep grinding and think, well, the little bit that I am doing is still a good cause, and I’m still fighting for these species and their right to exist on the landscape.