How does pressure affect duck hunting success? Or does it? Is it just the shooting, or do other related disturbance factors affect hunting success? How do ducks respond to hunting pressure? And what about busting out refuges — or changing sanctuary areas up to ensure ducks fly over our decoys instead? Dr. Bradley Cohen is back to explain the complex relationship between hunters, hunting pressure and waterfowl behavior, offering research-based suggestions for how we can mitigate disturbing “our ducks,” possibly increasing number of ducks hanging from our straps. Fascinating topic you’ll definitely want to hear!



Cohen Wildlife Research Lab conducts applied research to understand how habitat management and landscape conditions affect wildlife populations.

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Does It Pay to Be An Exciting Duck?

Ramsey Russell: Welcome back to Duck Season Somewhere. Question, is hunting pressure affecting duck hunting? I think we could all agree that it is. Refer to a previous podcast episode with today’s guest, Dr. Bradley Cohen from Tennessee Tech. Fabulous discussion, but we’re going to dig a little bit deeper today. If hunting pressure is affecting duck hunting, how is it affecting and how can we duck hunters mitigate it? I think that’s a great question we all need to answer. Bradley, how are you today?

Dr. Bradley Cohen: Doing well, man. How are you?

Ramsey Russell: I’m good. What’s your busy doing now? I keep up with you on Instagram and I love a lot of the data you all are presenting there. But what’s got you busy today? Are you all just monitoring? Are you all trapping? What are you doing today?

Dr. Bradley Cohen: Well, I think some of our kids are heading out soon to some of our study areas, we are doing some surveys on flooded corn. So what we do is we go into these cornfields that were flooded during season and right before they’re finished draining them, we go in and just see how much corn is left, just to see how much of it’s actually being used on the landscape. And then I stay busy during the springtime, we do a lot of turkey research, too, so I got a couple of crews out there catching turkeys still and tracking turkeys.

Ramsey Russell: Last time you were on the podcast, we were talking about hunting pressure. Does hunting pressure affect duck hunting? So I’ll just ask you again for the recap, does it? Does it affect hunting success?

Dr. Bradley Cohen: It’s such a broad question, but let me kind of give you a little bit of background of the study and say with the obvious disclaimer is this, this is one site in one area during a certain period of time, take everything I say with a grain of salt, I’m just telling you our research. Now, in the end of all things, what we partnered with TWRA, which is Tennessee Wildlife Resources Agency, who’s funding the study and US Fish & Wildlife service, they were interested in understanding the role of these refuges that we have, the federal and state owned refuges up and down the flyway. Now, originally the idea was, are they holding ducks? Can we disturb them? Which we did, we disturbed them. And that’s a whole other talk that you and I should have sometime of, like what happened when we disturbed these ducks off refuge. But the idea was to put GPS transmitters on these ducks and just kind of see where they go and see how much they relate to refuge and private lands nearby. And concurrently at the same time, what we did was we flew aerial planes, we just flew and we were just sampling, looking at how much water is available. And what we saw real quick is like it’s easy to see a blind in the air and that we could use mojo decoys to kind of see when people were hunting, like the spinning wing decoys, you can see them 500ft in the air from a plane, no problem when they’re spinning. So we’re like, all right, here’s a blind that’s being hunted, that’s being hunted and real quickly, we realized there’s so much hunting here, there’s so much pressure. It’s amazing that any duck ever survives migration down. And where the ducks are is where the hunting isn’t. That was it. So, yeah, hunting is affecting ducks.

Ramsey Russell: You were telling me in the last podcast that a lot of your ducks and we’ll talk about this later in the podcast, this philosophy of how these waterfowl aren’t just flying willy nilly down to the Deep South, they are coming to specific areas. And a lot of your research is demonstrating, for example, that cohorts of your mallards will come into this particular WMA or this refuge and throughout hunting season, the survivors, the war veterans, they basically stick to a script and never range within a mile and a half of their safe haven and they fly a certain pattern to avoid hunting pressure. And you’ve also done some research, I read one time and I think I extrapolated that within that mile and a half radius, there would be, on average, 43 active duck blinds. No wonder they’re sticking up there about 1000ft high, not even hear me call on my best of calling days.

Dr. Bradley Cohen: You said it perfectly. I’m telling you right now, for every hunter, listen to me, go out there, you either pay somebody, look at an aerial map, do something and just try and assess just how many hunters and hunting blinds are out there. You start to realize that eventually common sense is that ducks can’t be dynamic and I think of them as flying, I think of them as exciting. And I remember when we started this project, I remember sitting there with splitting headache, just so pissed because all of our “cool ducks”, the ones that were trading refuges, moving all around the state, they kept dying. And I was like, we cannot catch a break. And then I realized, like, no, the ones that are using one refuge that go to the same place at dark 30 and come back when you kick them up to go into the blind the next morning, those are the survivors, those are the ones that have a boring life and those are the ones that are going to make it back to the breeding grounds. Otherwise, it does not pay to be an exciting duck.

Ramsey Russell: Yeah, that’s crazy. How much hunting does it take to affect waterfowl behavior? Is opening day enough?

Dr. Bradley Cohen: Okay. All right, so let’s think about hunting as two different things, right? There’s the actual hunting is like, I guess, a shotgun blast, so you’re shooting at ducks and they hear it or you shoot at their group. The other is like, getting into the blind, messing around that general level of disturbance. So the answer is – all right, can I diverge just for a second? All right, so one part of our study that we’re doing, is we put up these acoustic recording units. Did I tell you this during the last interview? All right, you’re going to like this. So we put up these, what are called ARU, acoustic recording units, all they do is they look like a little box and all they are is just recording ambient sound, just recording, just a microphone out there recording. We put those up during the entire hunting season across our entire landscape because we’re interested in not like, what just ducks are doing, but how does that relate to hunter success? Because what we do is we take those recordings, we bring them back in the lab, we run them through a program and we can actually see every single shot that happened during our study. Now, what we then do is we go, okay, well, what’s one shot versus 5? We’ll just say that’s a shotgun that’s just one boom, they saw a duck or they saw a group. One volley, are we on the same page?

Ramsey Russell: Yes.

Dr. Bradley Cohen: All right. If you think of volleys as being some kind of indicator of how ducks even react to hunting pressure, our volleys after opening weekend decreased by 50% and never recovered. The key part of that also never recovered. In 3 years of study, we never saw some jump back up to the way it was after, similar to opening day. So that tells you just how adaptable these stocks are. Now, in any given year, a good day here, a good day there, a good day, of course, but across 3 years of data, opening weekend and then 50% and that’s it, stable line.

Duck Patterns

Ramsey Russell: That’s amazing, that’s incredible.

Dr. Bradley Cohen: That blew my mind.

Ramsey Russell: And it’s not just those volleys. Those volleys declined by 50% because the ducks got wary real quick, but it’s not just the shooting, is it?

Dr. Bradley Cohen: No. And like, our GPS transmitters say the same thing as those volleys, right? After 2 days, what you see is these ducks get in these patterns. But it’s not like all of a sudden on the 3rd day, they hear the shotgun volleys and like, oh, it’s still hunting season, no. What they start to relate to more and more, probably, is the disturbance of you actually going into the hunting blinds. Like, it’s not just that they’ve been shot at, that tells them, okay, I definitely don’t want to sit there again. But really, they have to know, like, well, how do I start my routine? And the way I think of it is this, let’s start in the evening, right at about dark 30, right at sunset, you know, all those ducks start leaving refuges, they are hungry, they’re waiting for illegal shooting lights. And you know that it doesn’t matter if you close the WMA off at 02:00 or you say, no more hunting from our blind from 11:00AM after or it’s at sunset. Those ducks know when the shots are ending, when it’s safe to come in and they come in, they’re eating. And what our ducks tend to do is we can literally see it. Like, they’re just waiting for you to kick them off when you go in to go hunting. So any of those boats going through those ATVs, all of them are disturbing ducks and teaching them this predictable pattern of, like, when I hear this, it means people are coming to shoot me, I think I’ll head back to the refuge and they just rinse and repeat.

Ramsey Russell: I don’t think that ducks like the noise. It’s something about the pitch of that noise –

Dr. Bradley Cohen: Of a surface drive?

Ramsey Russell: Of anything. I pulled up many years ago, Bradley, you’re probably in grad school or maybe not even in grad school yet. I was working for US Fish & Wildlife –

Dr. Bradley Cohen: I’m only 35.

Ramsey Russell: You were still in high school when this story took place. I pulled up to a federal sanctuary, working for US Fish & Wildlife service, I had to go pull some boards. And it was only one way in that time of year and that’s with an ATV and I pulled up to the gate. Before I could unlock the gate, just the idle of that little Kawasaki motor voided 640 acres of waterfowl. I told that story one time about 10 years later and some men I was hunting with that hunted the adjacent property, they looked at me and said, we remember that day. They remembered that day when I pulled up around 11:00 in the morning and they were sitting there talking about what’s for breakfast and 25,000 or 30,000 ducks came off that sanctuary to look around. But I’d never have forgotten that just the idling motor of that Kawasaki, which told me it could have been sound, but it may have had something to do with the pitch or the frequency or something they just don’t like about the sounds of these motors.

Dr. Bradley Cohen: There’s a guy, he’s a waterfowl ecologist for US Fish & Wildlife services, his name is Heath Haggie.

Ramsey Russell: I know him.

Dr. Bradley Cohen: Incredible research. When he was at forest biological station, he did a study that was like, we’re going to disturb ducks with different things, let’s say, planes different noises and we’re going to see how far away they are when they flush. And yeah, it was different across species. Like, mallards flush a little bit different than shovelers. But in the end of all things, it’s not just like the fact that they know a person’s there, the noise in general is they’ve learned over time, like, that noise is people, wherever that is, that’s probably not good. You know what I’m saying?

Ramsey Russell: Right. I think of ducks, they got a brain a size of a pea and I don’t think of them, of having cognitive mental capacities. We can think, but I think that they respond to patterns and to cues like a large mouth bass on a feeding. They become conditioned like Pavlov’s dog, they become conditioned to avoid that disturbance they associate with getting shot.

Dr. Bradley Cohen: Okay. Yeah. So let’s go to this. They have a pea sized brain and so I agree, like, how many times have you sat in the decoys and here come the ducks to land in your face, the ones that you can’t shoot any other time. I recognize that any moment in time, a duck can do stupid things, right. But think about it for a second. There’s only a couple of things that they are hardwired to do, survive and breed. When you put it that way, anything that is straight, so directly linked with one of those two, they’re going to have a strong reaction to it. So, yeah, they’re going to have a strong reaction to people trying to shoot at them or any type of association that would be around getting shot. And the second one would be, in the end of all things, they’re going to make decisions time and time again that increase their familiarity so they don’t have to make crazy attempts at trying to find things. So they’re going to try and go back to the same wintering area time and time again, they’re going to try and go back to the same breeding area time and time again. Does that make sense?

Do Ducks Seek Out Sanctuaries?

So our data suggests that basically, at any moment in time, 80% plus of our ducks are on refuge or within about a mile and change of it. 

Ramsey Russell: Yes, it sure does. I ran across something this year, I’m an old duck hunter now, old geezer, the OG duck hunter now and I was hunting up in Illinois with some friends, beautiful property, corn. All those properties up there have corn unless they’re too close to the Illinois River, then they’re moist soil. And they said, well, we’re going to get up in the morning, go and something. Well, I’d been traveling 100 days, I knew what time daylight was, so I got upstairs and adjusted my alarm clock and I knew what time to be downstairs because if you’re not early, you’re late, that’s all about my written book about duck hunting. What I’m about to tell you, the stories changed everything about that because I get up and nobody’s up, so I make a pot of coffee and nobody’s up, get on about my 3rd cup and the first guy comes down, the second guy, third, heck, man, I’m amped up now, we go out, nobody’s in a hurry, the sun’s coming up, it’s light, we’re loading the rangers, we’re getting ready, we’re getting sorted. And I said, are we not late? And somebody walks outside and looks and says, no, we’re not late. I said, but it’s 30, 45 minutes after daylight and they go, well, look, there’s no ducks. And I looked up in sky and I’m not understanding. He said, that means they’re sitting on us, they’re sitting still, they’re sitting on us right now. And for as far as you can see, Ramsay, all these clubs going back for decades, have a long standing rule that you don’t go onto the property with motorized vehicles or fire shots or nothing until the ducks are flying, until they’re up and moving. You don’t go in early and disturb them, because if you disturb them while they’re sitting there comfortably roosting, they ain’t coming back. And they may come back a day, but they ain’t coming back long term. And I go down, further down, follow that Illinois River down to the great confluence, I’m hunting with some clubs down there, same thing. Most of those members, most of those camps I hunted at don’t even go out until midday and they catch an afternoon hunt. And you’re there and the ducks are kind of flying around, then they start coming off a sanctuary and then they’re really flying and you’re done. And then you sit tight until everything settles down, then you go back out in the dark and that’s just the way they manage this hunting pressure, I’d never seen that before. And recently, I interviewed Mr. Knutson about Minnesota Duck Camps. Wouldn’t you figure, Bradley, that a state with 10,000 lakes must have some amazing duck hunting history? Well, it did. And somewhere along the way, we got to talking about Heron Lake down in Otter Tail County, more lakes in that county than any other county in the United States. And back in 1906, back when they were still estimating 70,000 to 100,000 canvasbacks on Heron Lake at times, back in 1906, preceding the Migratory Bird Treaty Act, he presented a pact, an agreement among all the clubs and club members on Heron Lake that one of the second rule was you will not go onto the water before 6:00 AM and you will not run across the open water where the ducks like to raft and you will be off the water and not shoot nowhere near it after 02:PM. I mean, again, it is that daylight thing and I’ve never really thought of something like that. So we’re not just talking about shooting or noise, we’re talking about just disturbance and letting the ducks have that area during the right amount of times. And I’ve never thought of that before as a factor of disturbance.

Dr. Bradley Cohen: No, I agree completely. I guess, we’ve both been around enough clubs to know, like, each club does it a little differently. But the general rule that I tell clubs I work with is if you’re holding the food, you don’t kick them off that food. You don’t get in there first thing and drive by them, they’re not coming back. It’s not just my data that supports this, all these studies show one thing, for the most part, is that once you kick them off, they’re flying to the refuge, they’re flying to the safe spot because they know the dance at this point.

Ramsey Russell: Is that primarily how waterfowl respond to disturbance is they go find safe areas, they’re where the hunting is not. Is that just in a nutshell, the only way they respond?

Dr. Bradley Cohen: So our data suggests that basically, at any moment in time, 80% plus of our ducks are on refuge or within about a mile and change of it. You got to think about it, you’ve been in enough clubs to know how limiting is food nowadays? I don’t know, there’s a lot of good research that’s going to address that, but I don’t know the answer to that, but I know what is limiting, that’s safe places and so they’re not going to – the quickest way to make sure there’s no ducks in your area is have nowhere for them to land safely.

Ramsey Russell: How important are sanctuaries? Because a lot of clubs that have enough property, I’ve been to parts of California, I’ve been to, of course, Illinois, Missouri, I’ve been to a lot of these big areas that sanctuary is vital. My club doesn’t lend itself to sanctuary, we barely have enough water for the members to hunt. But there are sanctuaries within 5 or 10 miles, federal or state rest areas or the properties that aren’t being hunted. And so how important is this sanctuary component to ensure hunting success within and how big of an area does a holding area or protected area affect, if that makes sense?

Taking Duck Sanctuaries to a Whole New Level

And really, in the end of all things, what we’re trying to do is create a stepping stone type system where they trade between these refuges, they also trade between these safe areas so that they redistribute the ducks. 

Dr. Bradley Cohen: Yeah, let me answer that in a little bit of a diatribe, but okay, let me tell you some things about what our study is suggesting. First thing is that most of our ducks make two flights a day, they make one to go eat in the evening and they make one to come back. Now, are there times they fly 3 or 10 times, sure. But for the most, it’s 2 times a day. Okay. How far are they going from the refuge? Well, our data suggests that in general, you could draw a circle around 2.5 miles of every refuge and that’s about as far as they’re going. That’s our place, right? A lot of food. So they don’t have to fly very far to find it. And basically, now I’m sitting there, I’m a duck, I just flew my 2 miles, I’ve eaten and somebody kicks me off. Am I going to go fly somewhere else to some refuge 10 miles away for safety or am I just going to fly back to the one I came from that’s 2 miles away? I’ll just fly 2 miles away. Okay, well, let me continue to explain. So that means the people that are within a mile or two of these refuges in our area, they’re seeing a lot of ducks. Now, they might not be shooting a lot of ducks because like I said, these ducks understand the game, they’ve now gone back and forth to that same refuge. In fact, like, 72% to 73% of our ducks use just one refuge the entire winter period, one refuge. Okay, so they know that that’s Jimbo calling over there or Ramsey calling over there, so they see a lot of ducks. But now you try and connect these refuges, now you’re somebody that’s 5 miles from refuge, you seen ducks? Some of them, you’ve certainly seen a couple, it’s a duck blind, I’m sure you didn’t buy just bare land, I’m sure there’s some reason you bought it. And there’s some ducks there, but there’s not nearly as many, you only have about 15% of the entire duck population that you’re seeing. All right, now let’s play this game. This is what our second part of this study that we’re doing is, we’re working with private landowners to actually create sanctuary areas. Now, how big of a sanctuary? We’re trying to figure that out because I don’t think it has to be very big, especially if you have different types of land cover. Like, think about it, how many times you’ve been in a flooded timber and watch ducks light? Oh, they land 100 yards from you, you shoot, next volley of ducks that come in and those ones that are 150 yards away from you don’t move. So I don’t think our ducks need big, gigantic safe areas, it just depends on what you can offer them. We’re testing that, we got anywhere from 80 acres of sanctuary size to, like, 400, all different types of cover. And really, in the end of all things, what we’re trying to do is create a stepping stone type system where they trade between these refuges, they also trade between these safe areas so that they redistribute the ducks. Because what we’re really showing and here’s the key, Ramsey, most ducks are super concentrated and there is not a strong, ubiquitous distribution of ducks across the landscape, that’s big. You’re either a winner or you’re a loser and I don’t have enough money in my pocket to buy a property that’s a winner right now. You see what I’m saying?

Ramsey Russell: Right. I get that. That’s a good way of putting. And talking about sanctuary, we’re not just talking about shooting, we’re talking about absolutely inviolate, no disturbance whatsoever. I remember out in California one time, Bradley, I was going down, there was a club and I was there during the offseason in August, somewhere up in Sac Valley old historic club. And what they did is, I don’t remember the exact acreage they had, but let’s say it was 2000 acres and the lower 2000, a lot of willows got into it and smart weeds and that’s where they hunted. The rice, they left completely for the ducks and a lot of the clubs did. And I remember going down a gravel road and every 100ft on the side of that road literally was a sign that says, don’t even stop to look at ducks during duck season, don’t even stop. There was a county road going through that sanctuary, but by gosh, don’t even stop, just keep driving. Don’t even stop to look and disturb my ducks who wanted to be peaceful. And that’s taking sanctuary to a whole another level.

Bill Lester: They need a place away from you, not away from just being shot at, away from you completely. That means silence, that means not seeing you, hearing you, feeling you. And based on some of that research for Heath Hagee, we’re thinking like a minimum has to be probably 80 acres to 100 acres. But I think based on what we’re seeing with even just some of the stuff preliminary with our timber spots or timber as in, I’m not talking mature hardwood timber, flooded bottom line, I’m talking just thick willow stuff like that. Shrub scrub they don’t need. So that’s why it’s easy to – we’re working on these partnerships with private landowners and I’m telling you, it’s an easy sell. You go give us your nastiest, thickest stuff that you can barely hunt anyway, promise us you won’t go in it and we think you’ll get better duck hunting. And I think so far it’s been well received.

Ramsey Russell: How does temporal sanctuary compare to spatial sanctuary?

Dr. Bradley Cohen: I’m not so sure. So temporal sanctuary is a couple of things, let’s think about it as, like, you will hunt every 3 days or something like that. What we see with our data is that, the first day after you come and hunt a place – All right, let’s just go through the motion. The ducks are there, the first assumption is that you kick the ducks off of where you’re hunting, which may or may not be true, but you kick the ducks off, they go back to refuge, you hunt, you do whatever, you shoot at a couple that are in those groups and then the next day, you don’t hunt and what we see is about 10% of our ducks come back the next day. The day after that, it’s still, like 25, about a quarter. So now we’re 3 days post hunting, and about 50% to 75% of our ducks are back and by day 4, most of our ducks are back in that area. So it takes 4 days of true rest to get all your ducks back. But, I mean, I don’t know if you visually could tell the difference between 750 ducks and 1000 ducks on an area, god bless you, maybe 3 days is just enough for you. You know what I’m saying? But underlying that is there’s a lag effect on you disturbing these ducks. It’s not instantaneous. So that’s the temporal sanctuary part. So when we talk about duck clubs and how often should I hunt, I guess, your objectives. But I wouldn’t do a Friday, Saturday, Sunday and then a Wednesday, that’s never recovering.

Ramsey Russell: Maybe do a Saturday, Sunday, let the ducks have it for the rest Monday, Tuesday, Wednesday, Thursday, Friday.

Dr. Bradley Cohen: Sure. I mean, you could do that 100%. You could do. We’re going to do a Saturday and a Sunday and then once in a while we’ll throw in a Wednesday. But having 4 days a week to hunt a place probably doesn’t work out as far as, like, they probably just perceive that no different than if you hunted it every day. You understand what I’m saying?

Effects of Disturbing Waterfowl Sanctuaries

Yes, the couple lucky neighbors right up against the refuge were shooting a couple of the birds, we rallied up, but otherwise, everyone in that area suffered.

Ramsey Russell: Yeah. What happens when you disturb refuges? You touched on that subject briefly. What happens? I’ve got a sanctuary sitting over here on my private property or there’s a WMA, because, here’s where I’m getting at, Bradley, there are people listening, there are people, public figures that are saying what we need to do is go into Fish & Wildlife service refuges and change the signs, change the areas and move it around and open it up for public, I’m like, come on.

Dr. Bradley Cohen: If I asked you that, what do you think? Okay, so I’m going to tell you what we did and then you guys tell me what you think would happen. So what we did, we had the exact question, that’s why we did this project, right? So we’re going to go in and we’re going to disturb these refuges. And when I’m talking disturbance, I’m talking everything from this light is like, we would go out there and walk around as if we’re burgers. Imagine if we just opened up some of these state and federally owned refuges, it’s burgers. Hey, that’s a stakeholder group of interest, let’s just see what happens there. All the way to as extreme as, now, we never shot at them, I’ll put that out there. But we would absolutely rip through the entire refuge on a surface drive, getting hundreds of thousands of ducks up for a long time get them moving. What do you think would happen? I’m talking like, not a single duck could sit still because we’re ripping through so fast.

Ramsey Russell: Well, as somebody that drove up to a gate one time on a Kawasaki 4 wheeler and the whole place bolted, I know there ain’t going to be a duck left. The question is, what are they going to do? Are they going to go to the next county? Are they going to buzz around and come back later? I don’t know.

Dr. Bradley Cohen: All right, so let me tell you, it’s the latter. All right, here’s the deal. So after a disturbance, after we disturbed these places, ducks would fly and then instantly come back a little bit after we left. For the next several days, they would move less, they’d fly less often, they would increase their site fidelity. So in other words, they would use that refuge more. And when we looked at our shotgun, our volleys, it was about a 50% reduction, give or take, like, basically 40 something percent reduction in shotgun volleys for the day we disturbed it. Now, if you looked at it, it would be perfect. Like you’d hear when we went in and disturbed this refuge, the neighboring properties, you’d hear pow, pow and then everything would go quiet. And, in fact, a bunch of our landowners said nearby would be like, we hated the days you disturbed the refuge, you messed those ducks up.

Ramsey Russell: Yeah.

Dr. Bradley Cohen: It’s like when you were a kid and you were scared, you had a nightmare or something.

Ramsey Russell: They’re just flying in blind terror, they’re scared shitless, they’re just flying with fear.

Dr. Bradley Cohen: What would you do? You would throw the cover over your head and just sit still. These ducks are like, what the hell is going on, this place is supposed to be safe. I ain’t leaving, I ain’t doing my normal stuff. And so it completely worked in reverse of what we had thought it would, which I think speaks even more to the importance of it. It’s not like they can’t go anywhere else, they’re like, oh, shit, this is all I have and I might not even have this anymore. I’m just going to find some fixed stuff in the safe area and hang out.

Ramsey Russell: But they’ve got to get off that little area in a lot of cases, they’ve got to get off, they’ve got to fly, they’ve got to feed, so they’re holding there, they’re safe. But they make themselves vulnerable as they get off to fly and feed in different day and weather again.

Dr. Bradley Cohen: Maybe. But if they’re not – Hold on, though. Let me play the devil’s advocate here. Underline that. Is your thought that ducks have to eat every day? Ducks don’t have to eat every day. Duck could sit still with the weather we’ve been having lately and duck could sit still, probably not eat for a couple of days.

Ramsey Russell: Really?

Dr. Bradley Cohen: Yeah. Think about it. How much do you think they’re really eating every time they go to these places? There’s probably enough to hold them over, I’m not saying they don’t leave, I’m just saying it messes with their normal pattern. They’re staying on the refuge more, they’re flying less, they’re just hunkering down. So it’s having the exact opposite effect. Yes, the couple lucky neighbors right up against the refuge were shooting a couple of the birds, we rallied up, but otherwise, everyone in that area suffered.

Ramsey Russell: Al Afton demonstrated the effects of disturbance. Bradley, you might have been in grade school if you’re only 38 years old, because it’s been a long time ago that he was cutting his teeth down Louisiana and a lot of the pintail and scaup, especially were 30 miles offshore. And they would feed during the days or feed at night and then fly. You might catch some late in the evening or early in the morning, but predominantly, the bulk of them were offshore somewhere that you ain’t going to hunt them.

Dr. Bradley Cohen: Yeah. So I grew up hunting on Long Island, you see the same thing, ducks that shouldn’t be out in the middle of ocean or out in the ocean and it just makes sense. Ducks in general, I think they’re going to finish their migration, the wintering migration in a general area, but that general area has to have someplace they will not get shot. I laugh when people say, we need to get rid of all these refugees and let everything be natural, like the way it was. No, people who own enough land to put sanctuaries are still going to put sanctuaries out and they’re going to be the ones holding all the ducks. You know what I’m saying? It won’t change anything.

Ramsey Russell: But in conclusion, what you just said about disturbing refuge is that as a duck hunter, it’s very frustrating to be sitting in a duck blind watching flock after flock pitch into an area that cannot be hunted. But at the same time, your research has demonstrated that if that refuge is disturbed, my hunting productivity is going to go down, not up.

Dr. Bradley Cohen: Yes. Here’s the bottom line. In the end of all things, I didn’t care which way the question landed, I just wanted to know the answer, in the end of all things, you should be thankful that you have refuges near you, there’s a reason you have ducks. And what we really want to do is figure out a way to move ducks around from refuge to refuge so they don’t know every single detail of every single blind around their refuge. So that way, maybe they’re a little dumber and make a couple more mistakes and are more likely to be harvested. The problem with hunting success right now isn’t the refuge that you’re seeing all your ducks being held up on, it’s the fact that they’re not trading around like they should, because everything is so compacted and disconnected from a safety standpoint.

Are Some Duck Species More Susceptible to Hunting Pressure?

I don’t know if the science is quite there yet, certainly, probably some are more tolerant of people and hunting pressure than others. 

Ramsey Russell: Amen. Do you find or have you stumbled upon – I know a lot of your research is oriented around mallards, that’s the king of duck, that’s the rock star and no doubt about it. But do you think, are some species more susceptible to hunting pressure than others or less susceptible to hunting pressure? Like blue wings for example.

Dr. Bradley Cohen: My personal hunting experience is shovelers really don’t care. But in all seriousness. I don’t know if the science is quite there yet, certainly, probably some are more tolerant of people and hunting pressure than others. But I mean, I was thinking, when you asked that question, you’ve been up to Saskatchewan, you’ve been up to prairie potholes before, right? What is the cardinal sin of hunting up in the prairie potholes?

Ramsey Russell: Don’t shoot the water.

Dr. Bradley Cohen: And why don’t we shoot the water?

Ramsey Russell: Because that’s where the ducks need to be and want to be and it’ll hold ducks and it provides a form of sanctuary. Now, what I’ve seen, let me clarify, the average guy going out there for vacation, self-hunting and driving around, he sees a bunch of ducks on this pond over here, this lake over here, that’s the body of water, you don’t shoot. But now what I’ve seen is these birds will come off a roost.

Dr. Bradley Cohen: Yes.

Ramsey Russell: And they will hit little ponds to drink and then they’ll come out to feed, then they’ll go back to hit a pond to drink, go back to the big pond to roost. And hitting those little drinking ponds does not seem to have a bad effect.

Dr. Bradley Cohen: I agree completely. You don’t hit the roost pond. Because we know the root shoot up the roost pond, it doesn’t matter if it’s a mallard or a wigeon or a teal, those ducks get up and move. You hit that roost pond, you mess everything up. And I think that speaks a lot to like, yeah, some ducks might have slight differences in how they perceive hunting risk or hunting pressure, but it ain’t that different. You know what I’m saying? Not to really matter.

Ramsey Russell: Yeah. And when do you think that during a drought, those areas are even more critical. Last year I was in western Manitoba hunt with some guys and it was dry. I mean, there were cracks. I believe I could have dropped a shotgun shell and it landed on the China man’s head, it was just that dry. And we found a field with some Canadas and ducks and went out to hunt it and as we were completing and getting our blinds finished, brushed in and everything else, well ahead of daylight, every duck and goose in the world was flying over all of a sudden. I mean, it was very weird because a lot of times when the birds are kind of coming in early, they’re coming in early and they’re trying to land on it, these birds weren’t, they were flying somewhere and it was just weird. And we’re like, what the heck is going on? Well, right there around shooting time, we heard some volleys. There were some boys from out of state freelancing, I guess it was their last day from what they said to the locals at the restaurant and they decided to go shoot that roost. And I could tell by the shooting it wasn’t a good hunt. I bet they shot 10 or 15 times max and we ended up doing okay, the birds kind of started wanting to come back and feed a little bit, and we did okay. But I always wondered whether or not those birds ever got back in that roost or whatever happened with that.

Dr. Bradley Cohen: I won’t say I’m above those out of staters, I have shot the roost pond before, more naive me didn’t realize the cardinal sins and learned real quick after I’ve had to relocate, that I’ll never do it again. I think that speaks to just the end all be all, which is that we know the answer is less hunting pressure and less disturbance to have more ducks. And most of your people there probably figuring like, well, how practical is that? How can I really even do that?

Fidelity to Wintering Grounds

So here’s a duck that flew, what, 3000 miles that year back and forth and her entire life was spent basically on 2 or 3 property owners land.

Ramsey Russell: Have you seen to where a lot of your research you’ve been posting on your Instagram account, you talk about this philopatry, this real strong fidelity that ducks have for the wintering grounds and also for their nesting grounds. Have you seen any instances, based on your research, that there’s so much hunting pressure in this area that ducks are beginning to use it less?

Dr. Bradley Cohen: Yeah, so that’s a great question. The answer is no, there’s more than enough space for them. They just need a little bit of space there and really, they have more than enough food. Listen to this, I just want you to understand, obviously, females have really high fidelity to their breeding sites. So we have one hen who for two years, literally laid a nest on top of a nest, even though she had flown 1500 miles to get there, like that high fidelity. Our ducks coming back in the fall, ready for this? Most of them leave in early November. They stop twice on their way down and by about December, all of our ducks are here. All right. Hold on. Yeah. And about 1 in 4 of them are right back to the exact spot that they were in. Like, I’m talking, like, put your foot down, that’s where they’re swimming today and that’s where they were swimming last year. And about 50% are within a 50 miles, 60 miles radius of us.

Ramsey Russell: That’s amazing. Every time I hear stories like that, I recall Dr. Doug Osborne over at University of Arkansas, Monticello.

Dr. Bradley Cohen: Yeah.

Ramsey Russell: He’s got some trapping area that they go out and band these ducks. And someone shot a hen wigeon 3 years after it was banded 7ft from where it had been banded.

Dr. Bradley Cohen: Yeah, that doesn’t surprise me. I mean, if you told me when we started this study, you told me that story, I’d be absolutely amazed. Now with all these stories that are coming out, all this data from multiple people, I’m not surprised. I mean, it makes sense. What proportion of our bag, of our harvest bag is actually adults? We know that down south we shoot the crap out of juveniles, we don’t shoot adults, as probably because you learn how to stay alive really quickly and you probably stay, if you can and go back to the same general area where you lived last time. That hen, I told you, she not only went back and nested on the exact same property 2 years in a row, like actually nesting spot, she wintered 2 years in a row on top of herself too. So here’s a duck that flew, what, 3000 miles that year back and forth and her entire life was spent basically on 2 or 3 property owners land.

Ramsey Russell: Just a minute ago you said, our ducks. Our ducks come back down to the exact same location, they’re here by a certain time. Our ducks. As more of these GPS transmitters, more of this data becomes available, you hear more stories about the wigeon shot 7 yards from where it was banded 3 years prior, you hear more stories like what you’re describing. And really and truly, on any given area I’m hunting, there’s a lot of sense to the fact I really am hunting my ducks, aren’t I? These ducks are coming into my property every year and they’re maybe bringing their fledgling with them, their offspring with them, but I mean, they’re coming to my property, those are my ducks I’m managing, aren’t they?

Dr. Bradley Cohen: You don’t want to be too bombastic with the findings, right? But I do think that if you look across everything we’re seeing, it certainly suggests that these ducks aren’t having these strong like, pulsatile migrations downward like we would think, right? Instead, they’re heading home. They’re heading to their wintering home. Now, do we still have some that push down like normal? Sure. Don’t get me wrong, ducks still do that too. But I’m just surprised at how many have a true home and they’re heading there. And like some of them are, we call them our Halloween birds. Some of them are home in their wintering grounds on top of us where we caught them by Halloween. Yeah, they’re my birds. And that’s why I really come back to this idea of if they’re going to be your birds, if we’re going to manage them like that, at that type of local scale, then we really need to provide everything we can to keep them happy and content. And in the end of all things, it’s so simple, minimize disturbance, whether you’re not hunting there as often as you want to be or you’re accessing the property on the edges, you’re trying to avoid using surface drives. I mean, just think smart about it.

Ramsey Russell: Speaking of that, you keep mentioning surface drives and I hear that a lot. We talk about disturbance, we talk about machinery and outboards and surface drives and everything else, just the sheer volume. By contrast, Scott Stevens, Ducks Unlimited Canada, also a student of Rick Kaminski’s well before your time. I hunted with him this year up at Delta Marsh and I can’t remember the exact acreage, I’m going to say 50,000 or 60,000 acres right on the south tip of Lake Manitoba just a beautiful, vibrant marsh. And we were hunting Eaton lodge and at daylight in the morning, so we had to see, we would get out into a canoe and we would paddle. And it was about a 30 or 45 minutes to where we were going, about 30, 45 minutes of just good, comfortable paddling. You weren’t cold when you got to where you were going, I’m going to tell you. And the whole marsh, the entire Delta Marsh, is closed to motorized vehicles, traffic for duck season. And yes, it’s a little exercise, it’s a little work, but what’s the hurry? The ducks are going to be there when you get there and we’re paddling along. And what shocked me was, he and I having to speak louder because we’re paddling and you got a little bumping going on, you got the ore sound splashing through the water, you got wind hitting you at times. So we’re having to talk a little loud, but nonetheless, the canvasbacks the ring necks, the scaup, the ducks are just swimming away. They’re not leaving bewildered, they’re not flying to the next county, they’re right there, 20 yards away, just swimming ahead of us just to stay. I was thinking to myself, my gosh, if this were a continental policy, how might it change hunting success.

Dr. Bradley Cohen: In the end of all things, think about how much, “sanctuary” in volatile sanctuary there was back in the day, oh, I don’t know, the heyday of duck hunting a couple decades ago, before surface drives, before OnX, before even just google maps, how many places were there where people, they weren’t great duck hunting areas, they were tough to get into, so we just let them be. How much of the landscape was safe for a duck? And now I want you to think about with surface drives with OnX, with the amount of money that people put into leasing property, how much actual land that a duck can land in is safe, is not hunted, is not disturbed.

Ramsey Russell: State and federal sanctuary is all I know, Bradley.

Dr. Bradley Cohen: Well, in the end of all things, man, I swear, if I could have a policy, I’d do the same thing, I’d get rid of those surface drives. I’d minimize the disturbance, because there’s something to that. There’s something to, if you can do just rowan access only or electric motor access only, I take an outboard access only. You’d open up some spots for ducks to land there and just kind of be content. It’s not an easy thing, though. These state agencies, what are they tasked with? They’re not just tasked with making sure every hunt that you have is quality, but they got to actually be able to put those people in places. It’s too much pressure, man. There’s not enough public land for you to go duck hunting. There’s too much pressure to make sure that you can get to every single spot you can.

Ramsey Russell: I was in a camp in Arkansas for 10 years, it was all pit blind out in rice or beans and dough board at ran, it was an absolute commandant. It wasn’t a democracy, it was his camp. And rule number one, there were plenty of rules, but one of the major rules in violate was the fact that there were no motorized vehicles in those fields during the duck season. You had to leave. Boy, if that bean field had been disked up or it was just one of those walks, it behoved you to leave a long time before daylight because you had a walk ahead of you. But it was so amazing, when you crawled down in those pit blinds, you heard ducks. There were times you walked up to the spread and got down the pit blind, that goose you’d seen walking around the spread was still there, that duck was still swimming in the decoys. And you would hear around you as you got quite in the blind, you would hear duck quacking. They may have swam and kind of swam out away from you, but they were still in that field. It made a huge difference.

Dr. Bradley Cohen: What we see time and time again, man, I told you, I’m doing turkey research, I’ve done deer research, what we know from turkey, what we know from deer and what we know from ducks is that animals respond to hunting pressure, they respond to disturbance and there’s two different ways you could go about it. Like you’re saying you can be real stealthy and I agree. Like in an optimal world, you would work with your neighboring properties and you put in the coarse center of your – if you can imagine, each one’s a little square. Well, in your bigger square, in the middle, you put a sanctuary and then you’d only hunt the edges, that’s what I do with the properties I work with. But another way to do it and I can’t tell you how many deer properties I’ve managed that we do this, every day, starting a month before the hunting season and on through, we’re driving our vehicles up and around, blinds. And so the deer start to learn that there’s going to be vehicle disturbance no matter what, that doesn’t mean you’re going to get shot. It’s just part of your life. You’re going to be out in that food plot, we’re going to be driving around and I’m telling you, you can condition them on the other side, you can condition them to be like, not every disturbance is your death. You know what I’m saying? Like the deer places that I hunt, you’re not allowed to get out of the blind until somebody comes and picks you up with a vehicle. Because we don’t want people, we know that the deer know that people walking through the food plot is death. But a car driving, that’s just part of their everyday.

Methods for Mitigating Hunting Pressure on Properties

Ramsey Russell: In respect to waterfowl, how can hunting pressure, and not just the shooting, but other related factors, how can it be mitigated at the property level and the landscape level? And I know we’re talking about scale here, what are your suggestions?

Dr. Bradley Cohen: Let’s talk scale. All right. End all, be all is at a property level, you got to set something aside that you don’t go into it. Like if you only have a blind, I understand that might not be practical for you, but then you got to figure out an easier or less disturbing way to get into your blind. And it depends if you have food or if you’re in the cover. If you’re in cover, you can get there early, you’re not going to kick a lot of ducks up, but if you’re hunting food, you don’t necessarily need to get there first thing in the morning.

Ramsey Russell: Right.

Dr. Bradley Cohen: You don’t need to kick those ducks up, you need to let them get off, if they’re going to. Now it’s a whole different, if they’re roosting and eating where you are, well, then you got a problem and you’re about to have no food anyway, so it shouldn’t be a problem for much longer. But listen, end all, be all is, it doesn’t have to be a huge part, you can work with your neighbors and just say, how about we all agree that thick brush over there that we can’t really hunt anyway, but one or two of us are driving through to get to our blinds, let’s try and sketch out a new way to get to blinds and leave that for the ducks. They’re going to use it because remember, it’s not food that’s limiting, it’s safe areas. They’re going to use thick, nasty stuff to get away from people. At a larger scale, we need more of it. We need to get these ducks up and moving all around and the only way we’re going to do that is providing them a continuous stepping stone all around, all of the landscape with safe areas. The more limiting safe areas are, the more concentrated the ducks will be, the worse the problem will get.

Ramsey Russell: Thank you for that. Have you seen any genetic relations? We’ve been talking to Phil Lavretsky of rescue several times and doing some stuff with him, we’re aware that there are old world and new world genetics, that old world genetics, those farm matters going back to the 1600s don’t tend to migrate and don’t tend to behave, they’re more like a husky dog than a wolf in his description. Do you see any differentiation? Are you far along enough in some research to differentiate that or do you have any thoughts on that?

Dr. Bradley Cohen: So we’ve worked with Phil, we have all the genetic signatures of all of our ducks and we’re looking into a couple of things with the different, you’ll call old world versus new world mallards, I will say that most of our mallards came back pretty genetically pure. Like, for some reason we didn’t get gigantic amounts of hybridization. But we’re not there yet. Call me next year or call me even sooner and I’ll let you know. In the end of all things, I think a lot of the waterfowl community thinks that there’s something to it, we just don’t know the true effect size. I think Phil has been a really strong scientist on that front and about a year or two, we’ll know better answer.

Ramsey Russell: Okay, what else you got going on? Tell me about some of these philopatric studies about all this information you’re putting out on the – we’re off a hunting pressure, we covered that topic really well today, thank you very much for that. Tell me, just in the last few minutes, what you got going on research there at Cohen Labs.

Dr. Bradley Cohen: Well, a lot of our stuff right now, we got two PhD students wrapping up. One of them is really looking at all the different things with the sanctuary disturbance. Another one is looking at a full lifecycle of a mallard. So, like, where are they going during spring migration? I can’t tell you how crazy it is. When they migrate through the spring, they eventually all converge into one population, it’s almost like there’s a funnel shape to our flyway. And so, in the end of all things, there’s a lot of overlap at one point in time between our Louisiana birds and our Tennessee birds because we’re working with Paul on that, he’s out in Louisiana, he’s got GPS. Anyway, that stuff’s crazy, right? But what’s even crazier is on their way down to no one’s surprised how concentrated that flight is. So we see that basically, most of our ducks select their full migration areas to be in not just big refuges, but in areas where there’s lots of clustering of refuges. So if you have a cluster of 3 or 4 refuges within 20 miles, that’s where our ducks are going to stop. Otherwise, we got another PhD student who’s looking at this whole thing of, like, can we incentivize sanctuary? And we’re going to start up a gadwall GPS tracking project soon. So we’re living the dream.

Ramsey Russell: Fantastic. I really do appreciate you coming on. How can people connect with you online and social media?

Dr. Bradley Cohen: So we have an Instagram and a Facebook page and it’s Cohen Wildlife Lab. I think the Instagram is Cohen Wildlife Research lab. But you type in Cohen and wildlife will come up. We post all kinds of cool maps, keep people informed of the science. We do turkey and deer work, too, so we throw some stuff out there if people are interested. But if you’re interested in just some cool maps on a Monday, we’ve got them for you.

Ramsey Russell: Bradley, thank you very much for taking time from your busy schedule to come and educate us on the effect of hunting pressure and how we can mitigate it.

Dr. Bradley Cohen: Hey, I appreciate you. Thanks for having me.

Ramsey Russell: Folks, thank you all for listening to this episode of Duck Season Somewhere, we’ve been talking to Dr. Bradley Cohen of Tennessee Tech about hunting pressure. Please share this with your friends, share it with all those knuckleheads you hunt with that need to hear how to increase your productivity rate and comment on Instagram and Spotify. Thank you all for listening to this episode of Duck Season Somewhere, we’ll see you next time.


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