Ep. 582 – Studying Mallard Ducks in Western Tennessee

Mike Brasher: Hey, everybody, welcome back. Thank you for joining us again on the Ducks Unlimited podcast. I am Dr. Mike Brasher, and I'm going to be your host on this episode. And we're finally here. We're finally going to do this episode. I'm here with Dr. Nick Masto and Dr. Abby Blake Bradshaw in studio with us. We have been trying to talk with this group about the West Tennessee Mallard Telemetry Project for, well, we've been trying in earnest for six months to get this conversation done. We ran into several obstacles along the way. We even this morning ran into another obstacle. Corey Highway was supposed to be with us today, but he was unable to join us. He apparently encountered some bad food yesterday. So, Corey, if you're listening to this, we certainly miss having you here in the studio. We're going to connect with you later on. for some of the work that you're continuing to do on this really amazing study that's been in the works here for a number of years. And it is really exciting to have Nick and Abby in studio with us. They have completed their dissertations, completed their research. And so I'm going to say welcome, Nick, to the Ducks Unlimited podcast.

Nick Masto: Appreciate you having me, Mike.

Mike Brasher: And Abby, same to you. It's great to have you. Thank you so much. And this is y'all's first time at National Headquarters. Sometimes that surprises me whenever I get guests that I mean, your colleagues, your friends, I've known you for a few years now. And I know you've been to Memphis before. And I just kind of assume sometimes that you've been to headquarters and but you haven't, so we're gonna take care of a little tour a little bit later on. But to start this out, I want to hear a little bit about each of you, your personal background, and then what you're doing now. So, Abby, we'll start with you.

Abby Blake Bradshaw: Yeah, absolutely. So, when I think about my personal background, I like to go all the way back, and I grew up in northern Minnesota, playing around in the lakes and the woods up there. I grew up from a mostly a an outdoorsy family, but a non-hunting family. And so I really got into duck hunting a little bit during my master's work. I went into the natural resources field, did some work on the prairies in Iowa and things like that, but then started working with ducks and was really hooked on that. And so just learning more about the duck world, the duck research world, got my hands dirty or got my hands wet. I guess both of those with getting experience with hunting and getting experience with just learning about the conservation, about the duck world. I was just super hooked. And so that's kind of my background. And I knew when I did my master's, I looked at wetland quality for migrating ducks in Illinois and had a really good experience there. I was co-advised by Dr. Jeff Matthews and Dr. Heath Hagee. now with the Fish and Wildlife Service, and it was just such a good experience that I knew I definitely wanted to stay in the field. So when this Mallard telemetry project came about, I jumped at the, really jumped at the opportunity and was really thankful that I did so.

Mike Brasher: What was it that hooked you? What was it about waterfowl that hooked you? Because you didn't grow up in a hunting family. You say that's the way a lot of us come to this profession, at least waterfowl profession, is that we've just always obsessed over ducks because we hunted them, but not for you. But what was it about them that you got so excited about?

Abby Blake Bradshaw: Well, I, I started off, um, doing, uh, core samples, which so the, the duck, that's not exciting. That's not exciting, but it, it put it kind of in perspective. So I was doing some of that work and actually not, not hating it as much as some of my peers did, but I got to do some Scott banding, some lesser Scott, some blue bill banding. Uh, right away. And they threw me in some waiters. I hopped out of a boat and started scooping ducks. And it was, it was just, I just remember calling, I think I called my husband, I called my parents like after that day and was just like, I did the coolest thing ever. And so I think just getting, getting hands on ducks, getting, getting out in the wetlands, putting waiters on for the first time, it was just, it was just such a cool experience. And I knew I just wanted to keep doing that.

Mike Brasher: That's really cool. Nick, you've been around ducks all your life, have you? No?

Nick Masto: No, I haven't. So I grew up in the upstate of South Carolina primarily and so most of the duck hunting there is wood duck swamps and I didn't have a lot of friends. My dad was actually more of an avid fisherman. He grew up in the on the Gulf Coast and in Tampa, Florida. And so he was a saltwater fisherman primarily. And he did his best, you know, to take us fishing, camping, hiking, all of those things. And so really just the love of outdoors early on kind of drew me. And then I went to Clemson University for my undergrad and encountered a number of wonderful mentors, both older and younger, got into dove hunting on Fance Grove, actually, with several friends and dove hunting is extraordinary. I hadn't done that. Right. And After dove hunting, I had a really great mentor, mutual friends, Rick Kaminski. I think you might know him. Yeah, I think you might know him. And, you know, his passion for ducks and waterfowl and waterfowl management and ecology is truly infectious. And so he sent me down to Nemours Wildlife Plantation where it really is just The land ethos and the waterfowl ethic down there in that landscape was gorgeous. I spent about a year and a half sorting through invertebrates and figuring out the invert and vegetation communities. I mean, that's how everyone starts.

Mike Brasher: I counted dots. I counted dots, collected core samples, did all that.

Nick Masto: It really punished me. I think it might be one of those things where it's like, alright, can they handle this? And then started my master's under Rick after that time. at Nemours conducting aerial surveys for estimating abundance of actually not just waterfowl, but the entire waterbird communities in coastal and inland South Carolina. And hopping in that plane really gives you some perspective about the landscape and the habitats that these birds use. And so we covered the gamut at a very large area with those aerial surveys. And so, I just kind of knew that I was going to continue waterfowl research, at least get my PhD. And actually, now that I think about it, you know, I was looking for a job. Coming out of your master's. Coming out of my master's. And I had done this prairie pothole field course put on by Delta, where I met Abby. And I actually called Abby on this project. I knew that she had gotten the job for this project. And I called her and apparently there was a spare PhD. Just a spare. And I think Abby got me the job. To be honest with you.

Abby Blake Bradshaw: Oh, no, you got it yourself. But I do remember like, yeah, either you called or we were just talking and it was just like, hey, this project is starting and it's getting bigger. And I met you on this trip. You were a lot of fun. You were super smart. I would love to be involved just with you further.

Nick Masto: Definitely not smart, but maybe fun.

Mike Brasher: That's wonderful. Now what I didn't do, I want to go back and ask you what you're doing now. Give people an idea of where you've moved on to.

Abby Blake Bradshaw: Yeah, absolutely. So I've kind of come full circle. So the place where I started doing these core samples and banding blue bills and everything, the Forest Biological Station, the Illinois Natural History Survey, I've come back and accepted a postdoc there and it's going great. We're looking at some similar… The project that I'm going to be working on is kind of similar, looking at landscape disturbance, but looking at hunting pressure and how that mallards and green-winged teal are using the Illinois River Valley. And so, yeah, I've got a postdoc there living back, living with my husband, got a house, working on the house, working on said house a lot. Um, it's, it's kind of a mess, but it's, it's, it's working out.

Mike Brasher: That sounds like you're in a great place. And so congratulations on that and look forward to hearing about some of the great work that you, uh, that you're going to be doing up there. And then Nick, you've moved on to a postdoc as well. Tell us what you're doing.

Nick Masto: I have, yeah. Right now I'm calling a lot of state biologists. So I'm working at the Cornell Lab of Ornithology, primarily trying to use these eBird status and trends models. So if, I guess, your listeners aren't familiar with eBird, it's a citizen science data set. And for a long time, they were making beautiful maps, right? But we didn't know what to do with them. And so the idea is, well, how can we use these for conservation applications? And the first step in that process is comparing them with more, I guess, structured waterfowl surveys. And so right now, what I'm doing is taking these eBird data and then trying to compare them to traditional aerial surveys or ground-based surveys that state agencies and National Wildlife staff conduct throughout the winter and even some into the spring. And then we're going to really validate, hey, is this eBird useful? Does it have some utility? And then if so, can we either jointly use it in habitat planning?

Mike Brasher: A whole bunch of different ways.

Nick Masto: Some of which we haven't figured out yet.

Mike Brasher: How can we use it is basically the big thing. Yeah, we've worked with you. We're going to continue working with you on that postdoc project. And we did have Dr. Oren Robinson on an episode of the DU podcast maybe a couple years ago now. And so yeah, if you haven't listened to that episode, just go back and search for it. I think you can probably search eBird and it'll come up, but I'll tell you a little bit more about that. And there's a lot to be learned there. This area of citizen science and participant science is a participatory science is really an exciting one. We're even doing a little bit of that ourselves here within Ducks Unlimited. Yeah, happy to have you be part of that. And we're gonna move into what is sure to be an exciting conversation, a lengthy conversation, I do believe, so settle in folks, this may end up being, we may split this into two episodes, don't know at this point, but this is a project that has received quite a bit of publicity, at least here, at least within the Mississippian Central Flyways, and I think you've actually developed quite a following across all of North America. It has been run out of the Cohen Wildlife Lab at Tennessee Tech University in Cookville, Tennessee, which is not a place that was on the radar of many of us in the waterfowl profession prior to this study. That lab and your supervisor, your advisor at Tennessee Tech, Dr. Brad Cohen, the, I guess, the brains behind this study when it came about, along with some of the other partners involved in it. And so, when I was reading through this final report, although some parts of the study, there's sort of a phase two of the study that we'll talk about a little bit later on, but this final report for phase one, I was looking at all of the different research questions that you had identified and addressed. It was astonishing. I mean, there's about, you could probably say there's a dozen you know, masters or PhD level questions in here and for y'all to have addressed those the way you did. And I'm sure there are innumerable other questions that have come to your mind, um, as you've been going through this and you're like, well, that's, we could do that and we could do this and we have the data for that. But anyway, there's a wealth of additional data that y'all collected and to inform some other questions. So, I guess to start off, who wants to give the kind of 30,000 foot view of what this, what this, what this, so we got some pointing going on here. Somebody has been nominated. So Nick, give us 30,000 foot view. You know, like you've, you've talked about this to a lot of different people. You've been at this for four years or so. And so give us that high level view, kind of orient us. And then we're going to go through this report and talk about some of the key questions and interesting things that you found, and so yeah, set us up.

Nick Masto: Yeah, okay, so let's see, 3,000 foot view. I think this project itself was born in a blind, and it was really, you know, what are birds doing in western Tennessee, right?

Mike Brasher: When we say birds, we're talking ducks.

Nick Masto: We're talking ducks. Mostly mallards. And in this, in phase one, it is only mallards, but you know, there's a couple reasons for that, but that I don't, probably don't need to explain, but yeah, so it was born out of a blind. What are Mallards doing in Western Tennessee? I think, I think that was basically like, it started as simple as that. Right. And, um, the biologists for the state, Jamie Fedderson and, and, and Brad and, and, and multiple other, uh, uh, state biologists, um, uh, Jason Maxdon and, and Larry Armstrong, they, they got together and they started thinking, you know, okay, well, how do we answer these type of questions? And it really started with, okay, well, we now have the technology to put miniaturized GPS backpacks on these birds, okay? Kind of secondarily to that, West Tennessee has a lot of state and federal waterfowl sanctuaries. I think the question was posed, what ecological values do these sanctuaries have, not only for the ducks, but for hunters? in the surrounding landscape, right? And could we maybe open up some access to these sanctuaries in different ways to maybe make birds move around more? I'm kind of putting the lead on Abby's project a little bit, but that basically sums it up. Now, I guess the last thing I'll say is it started snowballing, right? Where we have these GPS collars and we can get on these sanctuaries and okay, now let's, you know, we have GPS backpacks, now let's measure food and see, you know, how much food is out there, how much hunting pressure is out there. And so we were, I think it snowballed into a really, really amazing endeavor and ultimately amazing product where we were able to measure movements, disturbance, hunting pressure, food dynamics across a pretty large landscape. And I wrote in a recent paper that it's about the size of like lots of Yellowstone ecosystem studies. So Western Tennessee, basically.

Mike Brasher: The ancillary data, I call it ancillary, it turned out to be fundamental to the questions that you were asking. But it sort of the snowballing effect that you're like, well, we can measure this, well, we can measure this. Some of that is now enabled by the availability of remote data collection platforms, satellite imagery of different spatial scales and different sensors and things of that nature. But the other, it was just like, like all the aerial surveys that you conducted, not counting birds necessarily, but counting, inventorying kind of the habitat that was available. And you tell us about all that, that type of stuff as well. And collecting food abundance as food sampling in the wetlands layered on top of this, study just additional data set after additional data set, and it positioned y'all and the people that come after you to have a tremendous amount of information to, as you said, understand what birds are doing, why they're doing it, and then importantly, the reason I think it's gotten, in my view, the reason this has gotten so much attention, I mean, number one, you've used social media to your advantage to make people aware of it, but the reason you did that is because of its incredible relevance to the constituents that are helping to fund this, and we're going to talk about that a little bit later on. And TWRA as well, their primary constituents being waterfowl hunters across this landscape. There are other folks, other parts of the citizenry that benefit from all this, but let's be honest, hunters are what's driving a lot of the interest in some of these very specific questions. And so using social media to communicate and talk about, share some of these results is, it's a new thing that some researchers are doing. And I think when done correctly, it can be very useful for demonstrating the value of what y'all are doing and what we in Ducks Unlimited, what TWRA are doing to answer the questions that are important to those constituents and then use those answers to improve management, improve our conservation, improve the way we're delivering to try to address the needs of those people, right? So yeah, that's a great introduction. Then you even, the sanctuary, you know, Abby, that was, was that identified as your primary, like, that was one of the primary questions.

Abby Blake Bradshaw: That was kind of the main thing that I came on board for, basically. I mean, when talking to Brad back in, Oh my goodness, 2019. I was living up in Bismarck, North Dakota and was dealing with snow and everything up there, but we were talking and talking about a totally different landscape than I had experienced. But we were talking about the sanctuaries and everything and just seeing whether or not the utility of these sanctuaries, but also just whether or not we could actually open up these sanctuaries to maybe birders, or whether it would be okay to like take a school trip out, like things like that. Like could these sanctuaries handle that? Could they remain protective while having some other opportunities out there? And so that was one of the main things that I was just super excited about. I was really excited about the GPS backpack data. I've always been interested in movement data. And so I knew like kind of leaving my master's, seeing a lot of different, seeing that technology kind of come on board and just seeing other people's projects that were working with movement data. I knew I was really interested in that. combining the movement data with the management aspects of whether or not these sanctuaries could handle some additional sources of disturbance, essentially, or recreation. I knew, yeah, that was definitely something that I was really interested in.

Mike Brasher: Stay tuned to the Ducks Unlimited podcast, sponsored by Purina ProPlan, after these messages.

Mike Brasher: And there have been other studies through the years that have attempted to address some of these questions. Never in such a comprehensive fashion, I think it's fair to say, but you can go back several decades and find studies that have used the old VHF telemetry to track birds during winter and look at their their use patterns, habitat use patterns in response to opening and closing of hunting seasons, things of that nature. Now when you're using the old VHF telemetry, you're more limited in the number of locations that you can get, the precision of some of those locations. The frequency, the temporal scale at which you're getting that temporal frequency with which you're getting those, the transmitters, the tracking devices, I should say, that y'all were using allowed you to get millions of data points at much finer spatial and temporal scales. And that's been a big game changer for a lot of people. But then, Abby, to your specific research question, whenever I first heard about this study, it was a number of years ago, and Jamie Feddersen was talking about it, and that element where you were going to incorporate some experimental disturbance was really intriguing, because that's the question, and it's intuitive for hunters to be out there and see all these birds come into a sanctuary and they're like, man, I need to go, we need to go get those birds up. And if we didn't have all these sanctuaries, these birds would be all over us, you know, and the idea of experimentally disturbing those sanctuaries to try to probe that question a little bit more was really, really intriguing him. And I think a very large shout out goes to Jamie and the leadership of TWRA for being willing to do that. I know originally you had, at least I think originally, you were hoping to do some actual changing of maybe crossover experiment, opening and closing of sanctuaries from one year to the next. Maybe there was some initial discussion of that and maybe I know some of that didn't come to fruition because that's a big… Absolutely.

Abby Blake Bradshaw: It's people's sanctuaries. That's right.

Mike Brasher: It's a big challenge to do even what you did. Yeah, absolutely. In terms of the experimental disturbance. So, that probably gives us a good opportunity to do the acknowledgements, the thank yous to the people that made this possible. So, Abby, why don't you start? Who are the critical players in this, the funding entities and scientific leadership?

Abby Blake Bradshaw: Absolutely. So yeah, first want to thank Jamie Feddersen, thank Brad Cohen and all the TWA, the region one managers, like, holy cow, you guys let us out onto your sanctuaries to conduct some really awesome science. And we just can't thank you enough. Patrick Lemons, Larry Armstrong, um, yeah, just numerous, numerous folks out there that we just couldn't have done this without.

Mike Brasher: Did they get tired of y'all? What was their reaction whenever they first had this idea of experimental disturbance of their sanctuary?

Abby Blake Bradshaw: I think it was a few different reactions, some excitement, some apprehension for sure. But yeah, also just some interest in, well, okay, let's see what happens. That's awesome.

Mike Brasher: You know, whenever you do these things and you say, and this is, we'll talk a little bit later on about DU's involvement in this in a certain part of it. And that was my, I guess, reason for wanting us to be involved in some small way was that we had this, I guess, scientific expertise and we had the study design in place. to answer a question. If we're going to do a certain study related to some aspect of the benefits and implications of sanctuary on the landscape, let's make sure we do it in the context of answering a question. And that's exactly what y'all did. And that makes it easier for people, I think, to get on board with some of these experimental manipulations. It's like, look, we're going to do this, but we're going to measure the response, and we'll be able to learn from it. So, Nick, who else do we need to thank?

Nick Masto: Yeah, so Abby covered a lot of it. We really need to acknowledge the private landowners because, so Abby's project was specifically disturbing the sanctuaries, but other than, you know, we did a, we took a 3,000-foot view, right? And so we went on numerous people's property to measure vegetation characteristics. We need to thank the Fish and Wildlife Service, Southeast Region for paying for the aerial surveys, and gosh, the people out there, you know, were just unbelievable. I think that's a big thank you.

Mike Brasher: I think we've mentioned his name, but we'll do it again here. Dr. Heath Hagee also played a big role. He was on your committee, your dissertation committees as well, right?

Nick Masto: Both of ours, and he's the one who found that that fish and wildlife money.

Mike Brasher: Yeah, so shout out to Heath. He has been on the podcast a couple of times before, so I always appreciate everything that he brings to it, to our work. So yeah, obviously Corey is not here, Corey Highway, but he has already completed his master's degree and now he is continuing on for a PhD, answering some more questions related to this study and So, anybody, any other people associated with Corey's study that we want to acknowledge?

Nick Masto: Well, DU, and I think you can speak to that, but I think I should also thank DU as well, DU Canada and DU Inc. for a generous fellowship, the Spencer T. and Anne Olin Waterfowl and Wetlands Research Fellowship to help support that. I forgot to bring that up, but that's a huge thank you to Ducks Unlimited for contributing in a small way to my professional development.

Mike Brasher: Yeah, well, we always enjoy doing that. We were thankful for the opportunity to do so, and it's been great having you be one of our Ducks Unlimited fellows for the past few years. So, let's move on, then start talking about what you learned, and we have here in front of us this final report for that first phase and I think to start out with maybe We've sort of alluded to it, but just that you had Mallards marked with these backpack transmitters So just tell us a little bit about that Like what was the that was the those are the critters that gave you all the the data that was so important, right?

Nick Masto: So tell us about that Nick so I guess maybe let's just start with how we caught him and Sure. You know, so we were talking earlier before, before we got on air, uh, uh, we usually catch them in swimming traps or rocket nets. And for listeners that haven't heard of rocket nets there. essentially glorified pipe bombs attached to a net and you shoot them over the ducks, right? So all the birds were caught on waterfowl sanctuaries, right? Because you have to kind of congregate them in an area, baiting them in an area to catch them. We deployed approximately 500 GPS transmitters that kind of varies on, you know, censoring and things like that. But we deployed about 500 GPS transmitters from 2019 through 2022, those winters. Caught many more birds, probably banded well over 1,500 to 2,000 in the area. And those fixed rates, or the amount of times that the GPS took a location, we set to one hour frequency. So we were getting one hour locations day and night. on these birds throughout the winter, which is when we were catching them, and then all the way up until they, you know, through spring migration, and many of them, if the transmitter lasts, back down into fall migration, and so we have a lot of that.

Mike Brasher: So these were solar-powered backpacks? That's right. They weigh, what?

Abby Blake Bradshaw: About 20 grams.

Mike Brasher: About 20 grams, which is less than 5% of the body mass. Yeah, 2.5%. Catching them during winter, December, when did you start catching birds?

Abby Blake Bradshaw: We started our first, our earliest capture was the first of November. So we were trying to get a good number of birds before the hunting period to get some of that pre-hunting behavior, seeing if they're being more exploratory around the landscape and also to disturb them a little bit before and see their reactions, how that would differ outside of the hunting period and then during the hunting period when they're a bit more constrained, when it's a little bit more dangerous to leave the sanctuary.

Mike Brasher: And so yeah, solar powered GPS, they send this data back through GSM, through the cellular network, right? That's another advancement that we've made over the past, I don't know, 10 or 15 years with this technology.

Nick Masto: Yeah, about the size of a matchbox car for your listeners.

Mike Brasher: I'm sure a lot of people have seen photos of harvested ducks that are carrying these things now, because there are other studies going on across the U.S. and Canada that are using this technology. And this also reminds me that we should talk about the source of funding, because when you talk about 500 GPS units, that's several hundred thousand dollars. I mean, how much do these things cost? Is it $1,200, $1,500?

Abby Blake Bradshaw: It's come down a little bit, but they started out around $1,500 and it might be around the $1,200 mark now.

Mike Brasher: So you're getting over half a million dollars easily just in terms of these tracking device costs. Two PhDs, now a third PhD and a master's student, technicians you had involved in this, aircraft time and a whole bunch of other stuff. I think you were saying that the price tag on this, the first phase, was somewhere around $2 million. That's right. And so then we certainly want to acknowledge, I think what y'all told me before, is that the majority of that was made possible through Pittman-Robertson funds. Those are funds that come from the, uh, the 11% excise tax that is placed on the sale of guns and ammunition, archery equipment, and, uh, probably a few other things. And then the state kicks in some matching contributions to enable that those funds to flow to the state. So TWRA has, has a say in how those, those funds are spent and they saw fit to invest them in some incredibly influential. noteworthy research here on Mallard Ducks in West Tennessee and students and our future professionals in the fact that you guys are the ones that then get trained up and are going on to be our future leaders. So, the funding is made possible by hunters and by shooters and all the contributions that they make. So, thank you for that.

Abby Blake Bradshaw: Yes, thank you so much.

Mike Brasher: Yeah. So, all right, Nick, let's start off. first question that we want to talk about in terms of, I think we discussed sort of structuring this around sort of the life cycle of the ducks and when they first got here and some of the important questions that we wanted to answer with regard to movements and how birds were, how much they moved and how they moved in response to hunting seasons. Kind of give us the sketch on those questions, those important questions and some of the more notable results.

Nick Masto: Maybe we should start with just how little they moved. More of a surprising result, right? So we deployed 500 GPS transmitters because we fully expected many ducks to go to, you know, the Delta of Mississippi, Arkansas, down to Louisiana. And what was quite surprising was even if we're catching them in November, right? The vast majority I The numbers not coming to me, but it's like maybe 10 out of 500 or so. What what's the proportion there? Right? So They all stayed in Tennessee And that's across three winters. And so that was really, really impressive. And when they get here, they don't move very far at all. They're only making about a half a mile to a mile foraging flight to and from sanctuaries. Their space use, so they move less and use less space than a deer and a turkey when they set up their home range.

Mike Brasher: One of the notes I made last night whenever I was reading through this is one of the things we want to make sure we do is identify where your study challenges our conventional wisdom that we came into this study with and that we've learned from other studies. And I talked about past studies that have used VHF telemetry and so it's When birds leave the area, you don't always, it's harder to find them with VHF telemetry. There have been some incredible studies that have been conducted over the years on pintails, radio marking with VHF units, and marked birds in southwestern Louisiana, and Bobby Cox flew flights all the way up through Arkansas and north Louisiana and Mississippi trying to locate some of these birds, and he was able to. And that informed, I think, a lot of our thinking and understanding of how pintails will move around during winter. I think a lot of us have probably assumed that mallards were just as mobile, and they may be, and some are, a small percentage are, but not, I mean, the large percentage of birds that just that you captured in Tennessee and that stayed in Tennessee, I think it surprised everybody. And when you look at the work that's going on in Arkansas by Dr. Doug Osborne and his crew and Paul Link and others in southwestern Louisiana, I think, tell me if I'm wrong, but I think they're showing the same type of pattern, right?

Nick Masto: Yeah, Mike, it seems to me that based on all the ongoing studies on mallards and even pintails actually in certain places in southwest Louisiana. From Ohio to Arkansas to Tennessee to Louisiana, they all seem to be doing the same thing. They're establishing a territory during the winter, a range, right? Often the focal point of that range is a waterfowl sanctuary from which they kind of radiate out and make themselves available to hunters. But they're not, it doesn't appear as though they're moving you know, these really long distances like what we thought. And I think maybe I should probably bring up that it's pretty important to us that our GPS transmitters reflected the distribution of unmarked And so, what we actually did is we actually tested that and banded birds and looked at the distribution of direct harvests of banded birds to our GPS birds. And both survival and distributions were very similar. So, this pattern, we're pretty confident in the inferences that we're seeing from our GPS mark.

Mike Brasher: So, a whole bunch of interesting questions that come up because it makes you wonder if what we're seeing now has always been the case, Or have we seen some changes on the landscape in which waterfowl that they occupy and that they interact with that has caused them to maybe change their behavior? I don't know, but I'm sure those questions… It's kind of a chicken and the egg.

Abby Blake Bradshaw: I don't know if we can answer that with this new technology and changing landscapes at the same time.

Mike Brasher: You'd have to go back and, I mean, I guess banding data would probably be the only way you do that. Look at winter banded birds that are banded during the hunting season maybe and see where their recoveries were, but I don't know how abundant those data are. But, you know, the reason I think about that is one of the things that y'all discovered is just how heavily disturbed that landscape was, how many hunters are out there, how intensively hunted it is. And the general feeling is, don't have data to support this, is that there's more pressure there now than maybe what we had 20 or 30 years ago. And I'm not talking necessarily West Tennessee specifically, but I'm just, that's one of the dominant questions and conversations that you hear across the waterfowl hunting community right now is that the pressure is so intense, pressure is so intense. And if it has changed, if the pressure has, well, a number of things could be happening. Even if you held pressure constant, but reduce the amount of habitat, there you're effectively achieving a more pressured landscape, riskier landscape. But if you had both things going on, which is kind of what you're talking about, or more pressure and constrained less habitat and then you kind of get a double whammy and it could be affecting the behavior. And I know some of those questions are in the minds of you and Brad and probably Corey and so more questions. Pretty awesome. All right, so I probably took us off course there.

Nick Masto: Well, I don't think so. I think that hit the nail on the head probably and we just published a paper recently. I mean, we're thinking that, you know, with these landscapes are shrinking and even though Duck hunter numbers are declining. Hunters can also get anywhere that they want to go now, right? And that's changed within the last 15 years, you know, with these huge side-by-sides and mud motors and onyx and so on.

Mike Brasher: No place is unknown. No place is inaccessible.

Nick Masto: Right. These natural sanctuaries don't exist anymore. It's really just.

Mike Brasher: Yeah. Used to if you wanted to get used to if there was a place that existed that was very remote, you had to physically go in there or you had to have access to an aircraft or something. You had to have access to some privileged information in some way. Right. Or you just had to bust your tail to find it. Um, based on intensive scouting, but now you can just scout for wetlands kind of from your, from your phone. So it has definitely changed. All right. Let's see, let's move on then. Where do we go next? Like in terms of movements, um, home range area, you kind of talked about that. Yeah.

Nick Masto: I guess the only thing, so we did look at different ranges and flights and things during different time periods, right? And what we largely found, I guess the predominant theory is, okay, it's called refuging theory where, well, you know, they're going to spend a lot of time on the sanctuary, but the food is going to be depleted and they're going to have to move farther distances away throughout the season. And what we largely found is, is that doesn't seem to be the case in Western Tennessee. It could be the case in many other places, but, um, it looks to, it looks like, you know, there's enough food in and around the sanctuary that, that a bird can set up their, their spot and only use about one sanctuary. throughout the winter.

Mike Brasher: Now, if I remember correctly, they did increase the distance as the season went on, but it wasn't a huge increase, right? We're talking maybe a kilometer or two or something like that. That's right. Which is different than what was found in some other landscapes and some other studies. Southwestern Louisiana, I think. I don't remember what that what that change in distance was as it went throughout the season, but I know they would range out to, I think, 15 kilometers from their sanctuary. And it sounds about right. And so, yeah, an important reminder, and I'm sure we'll say it a lot of different times, many different times is that. Drawing proper inference from this study is important. The West Tennessee landscape is different from southwestern Louisiana. It's different from the panhandle of Texas. That doesn't mean that some elements of this don't hold. It just means that we can't jump to that point yet until you get this data from a different location of a different study. But yeah, for landscapes similar to what y'all had in western Tennessee. And maybe that's something that we should do is like kind of define that, because I wasn't as familiar with it. It's pretty unique I think. There's not a lot of rice agriculture there, right? So it's not like the Mississippi Alluvial Valley. It's not like the Central Valley of California. It's not like the Gulf Coast of Louisiana or Texas where you have this broad expanse of wetlands. So sort of define this landscape for us. Abby, why don't you do that?

Abby Blake Bradshaw: Yeah, so where we did our study in western Tennessee has just kind of more, it's not a sliver, but it's a little bit bigger slice than a sliver of the Mississippi River alluvial valley. And so there's some remnant wetlands and bottom lands, some cypress and tupelo swamps. there, but then we also had east to west tributaries, the Obayan, the Forcadeer, am I missing one? The Hatchee rivers going east to west. And so there was remnant wetlands surrounding those. And then a lot of the private landowners as well as public landowners were, for the most part, we weren't seeing rice, but we were seeing a lot of Corn standing on harvested corn during the hunting period. And so lots and lots of calories on the landscape. Also, a lot of moist soil management. So getting annual vegetation that provides seeds and things like that. And so It was a fragmented landscape in that there was a lot of agriculture, but then all the remnant wetlands and areas along the Mississippi and Obeyan River had a lot of flooded moist soil and corn. So yeah, lots of food out there for the ducks.

Mike Brasher: And my view of this landscape, and tell me if I'm reasonably correct, is that most of the habitat, and I think as a result most of the bird use, was constrained to some more linear, to those more linear floodplains of the Obayan, the Forkadier, and the Hatchee that extend out from the Mississippi River into that, yeah, to the east. So it's not this broad expanse, right? But a lot of ducks there, a lot of duck hunters. Did any of this work extend up into Real Foot Lake? Okay.

Nick Masto: So we had, um, it, it extended from real foot lake, um, all the way into Kentucky. We actually went up into Kentucky for that part of that part of real foot for some of the vegetation surveys and, uh, down to, uh, lower Hatchie is far South. Right. And then, uh, uh, We actually did include in some analyses refuges in Arkansas, so like Big Lake National Wildlife Refuge in Arkansas. We had some birds and some notions that, hey, we think our birds are coming back and forth from Arkansas to Chickasaw National Wildlife Refuge, for example. That wasn't very strong, but based on our telemetry, But yeah, so it was pretty large landscape. And, and, and, you know, Mike, you said something, it's pretty cool because we do have, we have these tributary systems where, you know, hunting is, is, is, is probably higher, like the pressure. Right. But then we also have this comparative sliver of the MAV, right. The, the, the almost kind of a natural comparison. Right. because we have about four or five, five refuges within that MAV area as well. And the other thing I might bring up is, and Abby will talk about it at length, is that just the sheer number of sanctuaries, it's like 13 sanctuaries, six federal and the rest are state-owned waterfowl sanctuaries. And so again, completely closed during the, during the hunting season. Wow.

Mike Brasher: And any any private landowners that manage any of their own properties as sanctuary that y'all know of?

Nick Masto: So that's a great question, and I don't know if you want me to get into it yet, but… Well, whatever you want to do. When we were doing the study, I would say largely no. We actually flew aerial surveys weekly.

Mike Brasher: But people started, I think I know where this is going, people started creating sanctuary in response to some of the results that you found?

Nick Masto: Is that what you're going to tell me? Yeah, that's in a nutshell, yeah. So I showed a map yesterday. I gave a presentation at the Tennessee Wildlife TWS meeting, and we were able to fly aerial surveys throughout the river tributaries and the Mississippi Valley. And we weren't counting ducks. We were counting people. So we were counting blinds and spinning wing decoys. And we were able to actually model that spatially. And what we found is that hunters, regardless of weekend versus weekday, hunters were hunting in our landscape.

Mike Brasher: So weekend warrior is kind of a misnomer here in West Texas.

Nick Masto: Yeah, not real here. All the time warrior. All 60 days. Yeah, it's hunting 60 days. You know, there's no difference in more hunting, for example, more active hunting later in the season, right, when there might be more ducks. Um, and so the pressure, which a duck perceives as, as, as high risk, right. Was intense and it was intense, ubiquitously across the whole season. So, um, yes, you, you kinda, you kinda hit that lead that, that the, and we'll We'll touch on it maybe later, but yeah, the next phase is, hey, maybe safety is truly the limiting factor, because what Abby just said was we had a lot of food everywhere.

Mike Brasher: So you mentioned later on that part of the next phase is sort of a deliberate sort of distributed sanctuary program, right, to see how that changes any of the bird behaviors, which I think is absolutely fascinating and a really, really cool extension of this project. But I guess, did you have, and those are, that there's a very deliberate effort to enroll people in those distributed sanctuary type of places. Did you have any landowners that, private landowners that before managed any of their property as sanctuary and have any of them done that now, just sort of their own volition, not as, not related to this other Second phase based on what y'all found based on what we found.

Nick Masto: No, not really. Not really. No, I do think that some of our outreach and some of our social media and some of our kind of getting ahead of it a little bit and I think Maybe just just anecdotally because we don't have data on yes, but and it's quite hard to get data on this but anecdotally people were like people were seeing the results and seeing some of the hunting pressure maps and and and perhaps resting, you know doing the best they can maybe to either rest areas and for a while or manage their shooting as best they can. But by and large, to answer your question, I think probably not. Not yet anyway. Yeah, not at a large scale.

Mike Brasher: And I want to, some people may be screaming at their radio right now. whenever they hear us talking about establishing more sanctuary, but the thing that is really cool and that is different, and it's really important for us to communicate this, is that the reason that we're looking into this relates to some of what you found regarding movements between refuges or whether they did or did not do that. And the interest here is in trying to figure out if there is a way to purposefully establish sanctuary spatially so that it can increase movements of birds and make them more accessible, give hunters a better opportunity for successful hunts. And so it's being done through sort of the combined eye of What do ducks need, but then how can we use that to also benefit hunters? And so that's key for people to understand is that this is not about trying to figure out how we can maximize the number of ducks that are on sanctuary, because it sounds like pretty much they all find them anyway, right now. That's right. That's right. But how can we, is there a way that we can manage sanctuary

Nick Masto: deliberately to achieve like hunter related objectives hunter satisfaction related objectives is that fair yeah and i think i think before i go i think it might be worthwhile to go to abby because she found so her experimental disturbance was also in the same vein hey Can we bump these birds off of sanctuary and achieve more hunter satisfaction? And so it might be worthwhile to go to her for her findings. Talk about that a little bit. Yeah, because and then we can switch back.

Mike Brasher: Let's do that. Before we do, let's take a break. And that's where we'll pick up. We still have a lot to discuss. We got to talk about phytopatry, winter phytopatry. We talked about, we can touch on one of the other little neat opportunities you had in terms of measuring bird response to an extreme weather event. and then probably a few other things here, but still a lot of great information to come. Abby, whenever we come back on the start of the next episode, we'll pick up and talk about your research specifically, sort of what kicked this all off, and the experimental disturbance of Sanctuary, a radical idea, but you did it. So, special thanks to Nick and Abby. Thank you all for being here. Thank you so much. Thank you. A very special thanks to our guests on today's episode, Dr. Nick Masto and Dr. Abby Blake Bradshaw. We appreciate their time. Appreciate them agreeing to stick around for another episode. And yeah, we look forward to that. We thank our producer, Chris Isaac, for the great work he does on these episodes. And we thank you, the listener, for supporting us and for your commitment to wetlands and waterfowl conservation.

Creators and Guests

Mike Brasher
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Mike Brasher
DUPodcast Science Host
Ep. 582 – Studying Mallard Ducks in Western Tennessee