EP 462. How Is Waterfowl Migration and Distribution Changing?

Are Ducks Still Coming South?

Waterfowl migrations are changing. Winter distributions of ducks are changing. 

Ramsey Russell: Welcome back to Mojos Duck Season Somewhere podcast, where today we’re diving off into the topic and asking ourselves the question, is waterfowl migration and distribution really changing? I mean, forever a lot of us hunters have been saying, yeah, it is changing, but what does the science say? Well, you might be surprised. Joining me today to help me muster through this topic is Mr. Heath Hagy. My buddy Heath Hagy with US Fish and Wildlife Service. Heath, how the heck are you?

Heath Hagy: I’m doing well. Thanks for having me, Ramsey.

Ramsey Russell: Introduce yourself real quick. I know you as a different Heath Hagy with US Fish and Wildlife Service, and now you’re in Bismarck, North Dakota.

Heath Hagy: That’s right.

Ramsey Russell: Your job title has changed. What you up to these days, Heath?

Heath Hagy: That’s right. Well, I’ve recently transitioned over to our habitat office in Bismarck, North Dakota. That’s a habitat and population evaluation team, so I work across the mountain prairie and Midwest regions. My team does supports conservation planning and delivery for the National Wildlife Refuge System and other partners. That’s a fancy way of saying we want to make sure we have enough habitat for ducks and then other grassland birds in the right places to make sure that breeding habitats not a limiting factor as far as we can control it. Formerly with my former position, I was the waterfowl ecologist for the southeast region, ranging from Arkansas over to North Carolina, down to Florida and Louisiana. So I still get to wear that hat occasionally and help out since that’s still a vacant position. And happy to sort of talk about waterfowl distribution changes today, which is really relevant to that southeast geography.

Ramsey Russell: It’s a big topic, especially us southern duck hunters have been questioning for years, are the ducks still coming as far south? Is something amiss? Is something changing? And recently, I don’t know, within the last couple of months, I was privy to an email with a lot of biologists such as yourself that I respect, Ric Kaminsky, Mike Frazier, yourself, and you had presented us with some links to some scientific papers that the science kind of agrees with what southern duck hunters are beginning to see. Is the migration changing? Are the migrational patterns of waterfowl changing, Heath?

Heath Hagy: You know what they say, right, getting a biologist to give you straight answers, like nailing Jell-O to a tree, right? Really, and I stole that from somewhere, I can’t remember where, but really challenging. But I’m going to do my best to shoot you straight. The answer is yes. Waterfowl migrations are changing. Winter distributions of ducks are changing. This won’t surprise many people, but the biggest change that we’ve had in the scientific community is information to illustrate that has just really started to come out over the last 2 to 3 years for us to really be able to quantify that change over time and space. There’s a ton of variation with how ducks move, of course, and migration chronologies and a lot of year to year variation in what ducks end up where and across species, which breeding populations, so on and so forth. And so it’s taken more complex analyses and a lot of people thinking really hard about the subject to be able to turn what many of us sort of our impression was, or anecdotal accounts were of, yeah, things are changing over to published science that says that exact thing. So really, it’s sort of really nice to have new information to be able to roll out to folks like yourself and your listeners to say, yes, things are changing, but here’s the Jell-O to a tree part, but it’s complicated. It’s not as if all the species or all the ducks are moving north in one direction. It really varies over space and time, and I’m sure we’ll get into some of those details here in a bit.

Ramsey Russell: We will. What would you say are some of the primary factors? In other words, why? What factors are influencing? Why is the migration and distribution of North American duck species, and geese, for that matter, one of the papers we read, why is it changing?

Heath Hagy: That’s actually much harder for us to tell you, to answer concisely than are things changing? We’re starting to get our arms around the fact that things are changing and here’s how much they’re changing, when, where, for what species, so on and so forth. The ‘why’ is still up in the air. It’s probably a combination of a lot of factors that are going to be really difficult for us to get our arms around. Some of the research says that as minimum temperatures change, as snow cover changes in the midwest and in northern areas, that’s going to influence some distribution of birds and migration chronology. But that’s not all species, it’s not even all individuals. They’re sort of not your average mallard, if you will. There’s a cohort of the population that they migrate, when, via time of year with light levels. There’s other individuals and other cohorts that are really going to stay north as long as they can and wait on snow cover. And so they’re sort of, and then there’s everything in the middle, just like there’s not your average duck hunter or your average biologist, there’s not one single mallard and so they all respond differently to these changes. But we know that temperature, we know that snow cover does influence, when they move, how far they move, some species more than others. And we think probably that other landscape variables are playing into that, too. That’s wetland availability, that is loss of coastal marshes, habitat availability in the south, lots of things in between that are probably affecting some of these changes.

Ramsey Russell: It’s easy. I mean, like you say, it’s complicated because there’s a lot of things going on at one time. How do you separate the pieces to see what’s influencing environmental change? Warmer winters, later arctic blasts, it seemed to be predominating over the past decade. This year was 54° in Edmonton, Alberta. You’re probably wearing short sleeves up there in Bismarck on Christmas Day this year. I mean, of course, a lot of the birds don’t need to migrate. When I start hearing stories about people shooting snow goose limits in Alberta on December 18th, I don’t expect to see a sky full of mallards down in the Deep South anymore. But there may be more than that going on. One of the interesting things I read in one of those papers was 1° Celsius, about 2° Fahrenheit would make those birds push just a little bit. It’s a very subtle change. I mean, it doesn’t take necessarily an arctic blast, but it might take a lot of snow cover to cover up their food to make birds move. So environmental change is something we’re going to have to grapple with now and in the future, isn’t it?

The Impacts of Environmental Changes on Duck Migration Patterns

So I know it’s complicated, but that’s sort of what we’re dealing with, trying to get our hands around how these birds move and how they don’t.

Heath Hagy: Big time. And it also depends, where you’re sitting because that temperature threshold is correct, but it changes based on how far north or how far south you are. So it’s much harder, meaning we have to get much more temperature change to get a mallard to go south after it settles in northeaster Arkansas or northeaster Oklahoma, kind of at that latitude. You may have to have several degrees and snow cover for a week or two to get that bird, that mallard to move. Whereas if that happens in Nebraska or northern Missouri or central Illinois, at that latitude, those birds are going to be more, they’ll more readily move. And so it depends on how far north you are, how much temperature change you really have to, have to push those birds. I know that’s kind of complicated, but the further south, the information we have today says the further south they get, the less apt they are to sort of move further south with temperature and snow changes, so on and so forth, they sort of sit tight. Yeah. Some of the new research that’s coming out is super interesting and show how few birds actually move, even when you have some of these extreme climactic events. Some of the research out of the colon lab I’m thinking of and other research out of northern prairie and other entities has suggested that birds can hold pretty tight, as in not move much at all for up to a week just sitting around during snow and ice, when these birds are sort of to their wintering ground, wherever that is. And so it depends if you’re in north Louisiana, just as an example, a 1° change Celsius or a couple of degree Fahrenheit, you probably aren’t going to expect any birds to come from central Arkansas move down to you, but that same change further north might really move some birds. So I know it’s complicated, but that’s sort of what we’re dealing with, trying to get our hands around how these birds move and how they don’t.

Ramsey Russell: It’s real complicated. I mean, and besides a changing landscape and environmental factors like warm winters, then you’ve got the whole, I don’t want to open up Pandora’s box, we’ve covered this topic before, but now you’ve got this old world genetic, where a lot of your old world genetic, let’s call them farm duck, for lack of a better word, game farm mallards, they’ll move as far south as they can, and that’s it. They’re give out. They can’t fly it, no matter what happens, they can’t fly anymore further south. One thing I want to talk about just real quickly, maybe this has been a better place to start off is some of the research you’re talking about, it wasn’t just like comparing last year to this year. I mean, one of the papers you sent, it was 60 years of data that you all started crunching. It was 60 years of data and looking at band recoveries, looking at things like the wing beads. Can you talk a little bit about some of the methods that would go into a long term study like that, like how exactly you all looked at it? So just so we can explain that we’re not just talking about year to year movement. We’re talking about a trend here.

Heath Hagy: Really good question. And I had a little audio issue. Is it still coming through okay?

Ramsey Russell: Yeah, it’s good.

Researching Duck Migration Trends

Some of the papers have actually looked at a lot of different data sources. So that’s another reason why we in the scientific community are getting very comfortable now, or at least more comfortable, sort of making some general statements about how things have changed and what’s influencing the change.

Heath Hagy: Okay. Perfect. Yes. Some of the papers have actually looked at a lot of different data sources. So that’s another reason why we in the scientific community are getting very comfortable now, or at least more comfortable, sort of making some general statements about how things have changed and what’s influencing the change. So a number of different papers have looked at a number of different data sets, and they kind of come up with similar conclusions. So people have looked at Christmas bird count data. That’s the Meehan Paper, Ric Kaminsky was on that paper where they looked at Christmas bird count data, kind of citizen science driven data. And they showed that there were changes in wintering latitude, and that temperature was a major factor. There’s research out of Mizzou USGS with Lisa Webb and Bron Verheisen and they’ve used a combination of band return data. So hunter harvested data and locations, parts collection survey, the Wingbee survey data, for instance, they’ve used a bunch of different data sources, all collected to sort of monitor populations and shown differences there. Another couple of researchers have tiptoed around this, looking at things that influence birds and migration to help us understand why. And they’re using implanted transmitters, backpack transmitters, so on and so forth. So all of these different data streams from all of these different techniques and analyses are all sort of coming together to help us understand how things are changing. It’s not just one data source, it’s not just last year to this year. It’s data from the 1960s to present that a number of these researchers have looked at to show that these things are changing. And I’m painting a broad brush here, but I do want to just say that it does vary. We aren’t seeing huge changes for some species in some areas, whereas other populations of that same species in another area, we are seeing larger changes. So it’s complicated. Some of the research from the –

Distribution Changes in Flyway Populations 

Ramsey Russell: Talk about some of those changes. Like, I noticed some of the stuff, it was Pacific Flyway versus midcontinent populations. Can you elaborate on that just a little bit? I know we’re talking generalizations, but it’s important.

Heath Hagy: Absolutely. So this gets really complicated. I’ll give you a couple of examples. Some of the work that Bron Verheisen out of University of Missouri has recently published illustrates that there are different distributions. So I looked at a kernel density estimate, or just kind of a distribution of birds, a big circle where those birds distribute in the winter. And it depends whether those birds come from the US prairies, the Canadian prairies, or the Great Lakes region. We get a little bit different signals where those birds distribute and how much they’ve moved for each species. So, for instance, one thing that they learned in that study or in those studies was that controlling for, let’s get really into the specifics, but controlling for where bands are deployed, so where we ban birds during the preseason to monitor populations, that’s super important on where those birds distribute in the winter, when we run that analysis. So we couldn’t just lump across. And some of the previous researchers that have failed to show changing distributions have lumped across all these geographies, sort of not recognizing or not having enough data to deal with the subtle changes in how band distribution has changed over time and sort of control for that. And so we see some much larger shifts for the Great Lakes population of mallards, for instance, than the prairie population of mallards. We see much subtler shifts in those birds that come from the Canadian prairies and boreal, for instance, to the southern Mississippi and Central Flyway. So very different. Depends on which population they come from.

Ramsey Russell: And for example, kind of what you’re talking about is a lot of the birds, banded in Alberta would go more towards the Pacific flyway. A lot of the birds in Manitoba would head down the Mississippi flyway. That’s some of the shift that you’re talking about? Some of the differentiation?

Heath Hagy: Absolutely, that’s absolutely part of it. Another interesting one, and I’m less familiar with this one, I wasn’t an author on this paper, but less familiar with this one. But the cox paper, really, from last year, had some interesting data where they showed some fairly large range expansions from birds breeding in the sort of central Canada. They actually showed some range expansions over into the Pacific flyway that were much larger in terms of sort of this kernel density area or that area where they distributed during fall and winter than the birds that came to the central flyway. So it depended. So from reasonably the same breeding area. If those birds went to the Pacific flyway, they had a much larger range expansion than if they came to the central and Mississippi flyway. So, super interesting. And it depends on where the birds come from, what species they are, and then which flyway they go to, and probably what those conditions are, because they’re certainly things are changing in different ways in the Pacific flyway, the northern Pacific flyway, then they’re changing in the Mississippi, central and Atlantic flyway. So again, when we dig into the specifics, it gets super complicated, and I know that can be frustrating to the average, to the average duck hunter, but it’s just hard to sort of pull apart all of these, and there’s just so much variation in what birds do in a given year. It’s taken us, 60, 70 years of accumulating this data set to be able to really begin to tease apart all of these intricacies.

Mallard Migration in the Mississippi Flyway 

So now, all of a sudden, instead of a migration area, you’re a wintering area and you have birds for longer than you traditionally did. 

Ramsey Russell: Can we pick some species. Mallards, pintails, blue winged teal, white fronts, and talk about them individually? Mallards being the rock star, that’s the one. I mean, I’m assuming most people are interested in. It would be a mallard duck and then a pintail. Those are the bread and butter ducks of North America. Maybe let’s just pick the mallard duck and talk about Pacific flyway versus the central Mississippi flyway.

Heath Hagy: Sure. And I don’t know that I have as much specific information on the Pacific flyway for mallards. It’s probably out there, but I don’t know that I have it off the top of my head. Forgive me, Pacific flyway, folks.

Ramsey Russell: That’s all right. We’ll talk about right in the middle of the continent, then the central Mississippi flyways. You know, for example, one thing, one thing I think I remember hearing is that, like, on the one hand, and again, it goes back to those different cohorts of birds you’re talking about, but on the one hand, it seems to be that some of the mallards are migrating earlier, but on the other hand, another part of them are migrating later and staying way up north. I’m talking way up north of where I’m sitting right now.

Heath Hagy: That’s right. Yeah. So when you look at the average of the core of the wintering range, right? So you’ve got to draw, so you sort of have all of these band return information and you draw a circle that says, all right, well, this is 50% of that. This is the core area. And you put a dot in the middle of that circle, the dots don’t actually – we haven’t shown that they’ve moved that much. So they might have shifted 100 km or 50 miles, or for another species, another 100 miles north. Well, that’s not this huge, it is biologically significant in some areas, and significant, certainly, if you’re on the bottom end of that or the top end of that shifting that range, but continent wide, that’s not this huge change. What is a big change, like I said, is if you’re on the top end of that range, right? So now, all of a sudden, instead of a migration area, you’re a wintering area and you have birds for longer than you traditionally did. Or unfortunately, if you’re on the southern end of this. So what looks like central and south Mississippi, central and south Louisiana, for instance, some areas in Texas at that latitude, the core wintering range for mallards in most years seems to have shifted north. That doesn’t mean that you have no mallards, but it means that those have dramatically, those band returns, which probably indexed the winter distribution have shifted north. And so if you’re in that area where things have shifted a few hundred miles, then that is going to be very significant for you. Then there’s also, I don’t know if it’s time to sort of get into the things you hear or not. But one thing I’ll just add here of evidence that we don’t have, we haven’t been able to show any of these large scale flyaway switching sort of changes. So, like, you hear sometimes, like, all the birds are over in Oklahoma or they’re all over in Kansas, or they’re all over in what was used to be in Kansas and Nebraska, all over in Arkansas, so on and so forth. But we don’t really have any information to suggest that. There’s a bit of information that suggest it –

Ramsey Russell: You don’t have a lot of proof for east and west shifts, but you do have north and south shifts. That makes personal perfect sense.

Heath Hagy: That’s correct.

Ramsey Russell: For example, when I read that the later migration mallards, that bulk of the migration you’re talking about is further north and we’re talking 450 to 600 miles further north, that is mind blowing. Now I’m remembering all those guys down in the Parish, Louisiana, or down around New Orleans that used to kill a lot of mallards, or the boys in Mississippi that used to shoot a lot of mallards, their ducks are sitting, and I did the math today they’re sitting at the great confluence in Missouri right now. I mean, that’s where those birds, that’s how far north the bulk of that migration is. We’re talking 500 to 600 miles north. It’s got to be all those heated ponds and bait piles up there that these NGO’s are laying out, right? I’m getting a little ahead of the horse there, but there’s so much more going on. We’ve mentioned environmental change, but when you start looking at landscape change, it reminds me of a text. I just got hungry wanting some information and texted my buddy Heath Hagy recently and said, Heath, how do we quantify the acres of habitat change and conversion and wetlands loss down in the deep south? And you basically explain that information is not in one source that we can just put our hands on, but it’s a litany of reasons that the habitat in the south has changed that could be aiding and abetting, along with environmental change, the reason why these birds are hanging 500 to 600 miles north and it’s not flooded corn. Am I right?

How Habitat Changes are Affecting Waterfowl Migration Patterns

Heath Hagy: That’s exactly right. There’s plenty of uneaten, unharvested flooded corn north of where these birds settle. So food is certainly a piece of where birds settle out, but probably not most and certainly not the biggest piece. It’s weather it’s where they were last year, it’s where their other conspecifics are, their buddies, where their buddies fly to. Probably all of these different factors influence where birds are going to settle out when they get to an area, those small scale movements, then it’s probably more influenced by a flooded corn pond or sanctuary. That’s another huge one, right where a bird feels safe moving around the landscape. But at scale it’s probably not an important factor. Just to illustrate, you mentioned white front end geese a minute ago. That’s actually one of the most significant examples that’s been published recently is the huge shift from really Texas over to Arkansas, averaging there, and I think that is like 750 or 1000 km, something like that. That’s a huge move in that core whitefront population over the last 40 years. And we don’t 100% know why that’s happened. Certainly there are plenty of hunters in Texas and hunters in Arkansas, I’m not sure it’s primarily driven by that. But we know there have been huge habitat changes in some of those areas with changes in, with water and drought in Texas, changes to the rice industry both in Texas and Louisiana. So probably some big habitat influences in those wintering whitefront populations moving again all the way from east Texas all the way over to Arkansas.

Historical Wintering Grounds of White-Fronted Geese

You talk about white fronted geese and I remember one time, a few times I’ve hunted with some and I’m talking, sure enough, serious, hardcore speckle belly hunters down in Louisiana.

Ramsey Russell: You talk about white fronted geese and I remember one time, a few times I’ve hunted with some and I’m talking, sure enough, serious, hardcore speckle belly hunters down in Louisiana. And man, I think they wrote the book on how to kill a speckle belly goose. I mean if you look at the top calls, speckle belly goose calls on earth, they all came from southwest Louisiana. Those guys know how to hunt geese. And one of the guys told me one time that at some point in time in history, 80% of the midcontinent population of white fronts used to overwinter down in Louisiana. And now a much smaller percent does. And you look around that landscape, you’ve got crawfish farms, which, boy, I don’t know, anybody loves to eat crawfish better than me. But you got propane cannons out on that landscape, you’ve got sugarcane moving in, you’ve got, like you mentioned, the Gulf coastal marsh is being lost. Seemed like every weather event. And then further up the flyway, you’ve got a lot of rice and soybeans and Ag crops that these geese can adapt to and eat. And I’m actually hearing of white fronted geese being hunted way up in Illinois now during winter, decoy sales are through the roof in that part of country. These birds are adaptable. They’ve got wings, they’re not going to fly any further south than they have to, and that makes a huge difference. How is their population doing, by the way? Are white fronts still pretty stable? Is our population growing like the Pacific flyway?

Heath Hagy: I don’t have the numbers in front of me, but I know the population traditionally has been stable. And I know that some people are concerned about it because the changes in harvest in some areas, how guide services and how successful folks are hunting white fronts. But I’m not aware that there’s any huge issue right now. Maybe you’ve got that information in front of you, Ramsey.

Changes in Pintail Migration

So they’re a bit more finicky where they’ll nest. They’re a bit more finicky where they go hang out in the winter. And it seems like they’re really apt to change those behaviors based on environmental factors.

Ramsey Russell: I don’t have it in front of me. Are you kidding? Sorry. But they seem to be doing leaps and bounds. They seem to be doing extremely well. What about the pintails? What is changing with their migration and distribution? Because one of the papers you sent had to do with mallards, pintails, blue winged teal, specifically. And they were all very different but the pintails seem to be likewise, maybe flying further south on the first push, but hanging further north.

Heath Hagy: That’s right. Pintails, like, I guess, don’t quote me on this, but from a planning standpoint, pintails are a weird duck. They are a hard duck to figure out because they’re very responsive to environmental factors, and they’re not as, I hate to say, dependable on going to a place as a mallard, but they have less fidelity to any one site. So they’re a bit more finicky where they’ll nest. They’re a bit more finicky where they go hang out in the winter. And it seems like they’re really apt to change those behaviors based on environmental factors. And so that’s a little bit of a challenge. But actually, some of the biggest movements, really, that we’ve been able to show or that other researchers have been able to show are some of those shifting distributions of pintail. Classically large portion of the pintails went to southern Louisiana, to those coastal marshes, to lack of seen refuge, Sabine Cameron Prairie, some of those large refuges in Louisiana, and certainly a large number do today, but less do. And they seem to have spread out across the Mississippi valley, east Texas, they seem to be much more spread out than they used to be. And some of those distribution changes for those birds, certainly that harvest distribution has pulled much farther north than what we’ve seen for some of the other species. Why is that? I don’t know. Probably changing water distribution in the Mississippi Valley has something to do with it. Maybe where those birds nest, like I mentioned, making sure that you control for subpopulation or those cohorts of birds where they come from seems to be really important. And so as the breeding areas have changed, which we have had some major changes in where birds are produced over the last 20 or 30 years, as far as we can tell, in the US prairies, that’s probably impacted where those birds end up as well. Lots to unpack there with the pintail.

How Have Blue-Winged Teal Patterns Changed?

And also we see some interesting signals with their data, where we do see some distribution changes and even some southern shifts in some months and then some northern shifts in other months. 

Ramsey Russell: It’s a lot to unpack. What about the blue winged teal? They seem to be. I mean, just because they’re little old behavior, they’re going to fly with a full moon and a north wind. They’re heading to Mexico, baby. I mean, they’re flying south. But what are we seeing changing with their migration distribution? Anything?

Heath Hagy: A little bit of puff of 60° weather and it seems like they are rolling on in September. Blue wings are an interesting one and a little bit hard to figure out, but luckily we’ve had a lot more band data, band deployments on blue wings in the last 20 or 30 years. And so they’re actually, one of our most commonly banded, duck preseason banded ducks in North America these days. And so we have a lot more information. So a couple of things, we know. We have a lot more blue wings, as far as we can tell, that stay in the US each year. So typically we would have lost a majority of the population, maybe 90% plus probably to Mexico and places farther south. We seem to be wintering, as far as we can tell, a much larger percentage of the population, I don’t have an exact number, but certainly a much larger percent of that population stays in the US now as compared to 40, 50 years ago. And also we see some interesting signals with their data, where we do see some distribution changes and even some southern shifts in some months and then some northern shifts in other months. And so that’s one of the papers that Bron Verheisen has authored. He actually broke things down by month. And that’s super interesting because we don’t see changes throughout. Again, it’s complicated. We don’t see changes throughout the whole winter period. We see that things may look very different in distribution in January than they do in October. So you may actually have a completely different signal where we have birds arriving earlier in October, but maybe being later in January or vice versa. So it’s kind of a nightmare to sort of break it all apart across all the different species. And blue wing teal are certainly a species that has some changes there.

Ramsey Russell: Waterfowler adaptable to a changing landscape, and so are duck hunters. I love a mallard duck and I love pintails, lord help me, I love a mallard duck, but I love a blue winged teal also. And a lot of my buddies down in Louisiana, Damon Heber, for example, good buddy of mine, but he talks about how blue winged teal have kind of become a surrogate of his duck season with all these migrational changes. He scheduled a lot of his leave time, and so do I, to go chase blue winged teal because those little boogers are coming through. They’re coming. And it may be a matter of a cold front or full moon or timing, but they’re coming through. They’re coming through during that period of time. They’re going to provide some good hunting opportunity. They eat good and they’re fun to hunt. So there is a silver lining, they still like a lot of that habitat that’s available down in the deep south for us to hunt.

Heath Hagy: Absolutely. Yeah. And as populations have changed, you know, we had some upticks in blue wing teal population, Gadwall population. And so those in some places have replaced, some of the changes in mallard, ringneck population, that’s a little bit hard for us to get our hands around continent wide. But certainly ringnecks are another interesting one that seems to maybe have replaced some of the bag limits in some of the areas further south and southeast US.

North America’s Changing Landscape for Geese

And so with that, Canada geese were really, when there was more food available, expansion of corn northward westward, Canada geese have a readily available food source in the fields. 

Ramsey Russell: Some of my most treasured possessions, my grandfather’s one that more or less introduced me into this thing. And some of my most treasured possessions are some old papers, not a whole collection of them, but a few of them I found rummaging through some old stuff one time. And it was notes and budget for what he called Goose Camp. Right there in the Mississippi Delta back in the 50s and early 60s. He and a collection of guys used to take two weeks off and go out on a boat down in Lake Ferguson and go out to the sandbar at the Mississippi River and dig in and camp for a couple of weeks and target the interior population of migratory Canadas that still came to the deep south back in those days. And then by the 70s, they were loading up in a car and driving up to parts of Illinois to crab orchard to go shoot their Canada geese. And as I talked to a lot of the old timers in the deep south, especially around Mississippi, that generation, they identified more as goose hunters than duck hunters back in the 40s and 50s. They were goose hunters. Well, the geese don’t fly south anymore like that. And when I think back, I was in a conversation with Jeff Watt and yesterday talking about his Osage Basin Habitat project up there in Missouri and surrounding areas. And it just occurred to us, we were talking about a lot of moist soil management and wetlands management, stuff like that. But if you think about this Heath, North America’s waterfowl, existed for millions of years, let’s say. But landscape agriculture on the North American landscape is really kind of a new phenomenon, 150 years old and those geese quickly adapted to that change in landscape. Boy, I mean, they feed on dry fields, they feed in commercial agriculture. As it expanded up, they began to shortstop and adapt accordingly. And I’ll ask the question like this. Let’s just remove environment, let’s remove “global warming” from the equation. What do you think or what have you seen in some of this research that the change in distribution and migrational pattern says about just, let’s just say North America as a changing landscape in the last 10, 20, 30 years?

Heath Hagy: Yeah, I’d probably even go back farther than that. Yeah. We haven’t even talked about Canada geese because that changed happened, began happening 60, 70 years ago.

Ramsey Russell: Yeah. That ship’s already sailed.

Heath Hagy: Ship has sailed, right. For arctic or subarctic nesting Canada goose species? They have not everywhere. The Central Flyway is a little bit different than the Mississippi and Atlantic Flyways, but, yeah, we have some refuges that were put on the ground for arctic nesting, sub arctic nesting geese, and get zero and have gotten zero for decades and decades now. And it’s just a huge change in those species. And why, you ask? Geese are a larger bodied species of waterfowl. They’re able to more readily adapt to cold weather. They can carry more fat reserves, energy reserves. And so the smaller the bird, the less sort of able to deal with cold weather and persist at northern latitudes and sort of deal with that environmental variation, right? Like green winged teal are living on the energetic edge a bit more on average, than a Canada goose, right? They don’t have as much buffer. And so with that, Canada geese were really, when there was more food available, expansion of corn northward westward, Canada geese have a readily available food source in the fields. And the other thing that’s not talked about a whole lot is expansion of open water from all of the reservoir building that we did in the US, especially, other places have done it too. But reservoirs and especially areas that stay open, power plant, cooling lake, so on and so forth, there’s a lot of open water, a lot more open water in the midcontinent and mid latitude and northern latitude areas than there was 50 years ago. And so those two things together, they’ve got a food source there. In some cases, they can persist beyond the end of hunting season. Hunting season shuts down in northern and mid latitude areas and then opens up in the south. So the longer that they can persist, they’re essentially in a sanctuary area. And in some states, if they can persist and go field feed and find some open water on reservoirs or cooling lakes, that’s what they’re going to do. And so, yes, landscape and our changes, too. Human changes have benefited some of these species. I didn’t even talk about development and all of the ponds and developed areas and how readily a lot of the Canada geese species, subspecies, really have adapted to that. So certainly we can’t quantify it exactly for a lot of birds. But we certainly know that our changes to the landscape have a big part to do with influencing how birds use the landscape and probably influencing these landscape changes independent of climate change and warming temperatures, so on and so forth.

More Hunters and Less Hunting Habitat

So we like to be as responsive as we can to those questions that come in from duck hunters and from national wildlife refuge system managers, from state WMA managers, it matters how many ducks we expect to show up and what kinds, so that we know what to put on the ground. 

Ramsey Russell: It’s a vastly changing landscape. And to me, it’s a shrinking landscape, a highly fragmented landscape. That’s why hunting pressure enters into the equation. That’s why the boat ramps are so crowded. We 900,000 duck hunters in the United States are becoming more highly concentrated in a very shrinking landscape. And it’s beginning to show, isn’t it?

Heath Hagy: It sure seems that way. And we have things pushing and pulling on the habitat equation really hard. We don’t have remote sensing and our models good enough yet to be able to sort of quantify precisely how the energy landscape you ask me about, like, hey, how has food changed? Well, we don’t really know because we’re just getting to the point where sort of we can use remote sensing and be confident in our estimates to say there was this much food here in this area without going into it, and it’s intensive project. So going forward, we’ll be able to have some of that information. But it’s hard for us to go back in time and sort of figure out exactly what the food on the landscape at the scale of Mississippi, Louisville Valley or the state of Illinois or somewhere like that is. So we’ll have that going forward. But it’s hard to know how all of that is interplayed with bird migrations in the past.

Ramsey Russell: A lot of the research we’re discussing is fairly recent, last couple of years. Why all of a sudden was the interest in this research? What do you think? What was the purpose of these research projects? Looking at migration distribution?

Heath Hagy: We’ve certainly had an increase in some of this research. We had a paper, actually lead authors were green increments from about 20 years ago, and they looked at this winter distribution question and weren’t able to show any substantial differences. And so that, I think we use that for a while because they had a really comprehensive look at it. But we had more data come available. We’ve had better statistical models come available, more people interested. Also to get to your, so that has been a change over the last 20 years or so in our ability to sort of go, well, we can’t detect any changes. Oh, we can now show changes from all of these different data sets. But to your question, I mean, we want to be responsive to the hunters, to the conservation community, there are questions every duck season about where are the ducks? And sometimes it gets quiet because the migration, major migration event has happened and people are busy out doing well in the duck blind. For me, that wasn’t this year for sure. I was wondering where the ducks were too, this past winter. So we like to be as responsive as we can to those questions that come in from duck hunters and from national wildlife refuge system managers, from state WMA managers, it matters how many ducks we expect to show up and what kinds, so that we know what to put on the ground. Right. I mean, some birds aren’t going to respond to agriculture or to moist soil, they’re going to respond to something else. And so we need to know, as natural resource managers, what we expect to show up and for how long so that we can plan to provide enough food on our areas in combination with what we think is out on the landscape on private lands.

Ramsey Russell: A couple of questions I forgot to ask you before we – I’m going to follow back up on this topic. I was leading into something. How did the amount of juvenile mallards or pintails, how did the age ratios influence migration of mallards? As I understood the paper, it really didn’t matter. It didn’t matter how many young birds or old birds it was as regards mallards and pintails, migrating further south or staying back further north did it?

Heath Hagy: For the most part, we either haven’t had enough data to really test the effect of age, or the results haven’t really been striking where we’ve been able to do that. I suspect there sort of biologically might be or should be some difference there in adult birds finding winter distributions or migrating slightly differently than young birds who are more naive to the landscape. We really should be able to find, or we think we should be able to find some of those differences, but we largely, in these series of papers, we largely haven’t been able to show that in a really significant way. There are some subtle things that we’ve seen, and part of it is just a lack of data. I know we’re saying 60 or 70 years worth of banding data and harvest data, but when you start breaking that down by subpopulation and by age and sex cohort, and we only get band returns. We have to deploy, what, 100 bands to get 15 or 20 band returns. And so you have to deploy a lot of bands to really dig into that question. And we deploy fewer bands now than we did 20 or 30 years ago. So that’s all sort of this part of this equation is we need more and more data to be able to dig into those very specific age and sex ratio questions. So, good question, we just don’t have a lot of information to suggest that there are huge differences, although many of us suspect that there may be.

Have Numbers Changed Similarly in Diver Ducks vs Dabbler Ducks?

The diving ducks in a couple of papers tended to be a bit more variable. 

Ramsey Russell: And another question I forgot to ask. In any of this research, did you all look at diving duck species versus dabblers? Was it pretty much the same trend among the same?

Heath Hagy: No.

Ramsey Russell: Okay.

Heath Hagy: Not exactly. So at large scale, did they do something vastly different? Not exactly. But a couple of papers looked at diving ducks and dabbling ducks, looked at all the individual species, and then sort of looked at the gills. Mallards, pintail, green wing teal, wigeons, so on and so forth for dabbling ducks, buffleheads, canvasback, goldeneye, scaup, et cetera, redheads for diving ducks. The diving ducks in a couple of papers tended to be a bit more variable. It was hard to say, they’re doing this or they’re doing that, whereas the dabbling ducks. We can look at a couple of papers and say, well, a lot of the dabbling ducks are wintering farther north, especially when you hit December and January, almost all those species are showing distribution shifts to the north. Diving ducks were much more variable by species. So you had a couple, for instance, Goldeneye. There was a northern shift signal in the Verheisen paper there. Buffleheads, there was a northern shift signal for canvasbacks, it was opposite. There was a little bit of a southern shift. We didn’t talk much about this. I probably should have brought it up when we talked about blue winged teal, but we actually, in some months, showed really substantial southern shifts in distribution. Blue winged teal, a lot of the dabbling ducks –

Ramsey Russell: Meaning they were distributing further south in the flyway.

Heath Hagy: The band returns actually showed that more birds, a larger percentage of that population, was being harvested farther south by a couple hundred kilometers, as opposed to a couple of north. But then when those birds, when we looked at December and January, there was either no change from historic or they were farther north. So there’s a bit of a contraction, if you can think about that. So early in the season, we’re actually seeing for the dabbling ducks some southern shifts, and then at the end of the season, we’re seeing some northern shifts in the harvest distribution.

Ramsey Russell: I asked that question. And that starting to make kind of sense to me. And I’ll tell you why is blue winged teal further south, some of these canvasbacks farther south? You know, what’s the difference in those two species versus a mallard and a pintail are? To me, they’re more wetland obligate species.

Heath Hagy: Very good. I agree.

Ramsey Russell: And so as we’re looking at a change in landscape, draining of wetlands, tiling of fields, planting of row crop, agriculture, or civilization further up the flyway, they’re coming further south to get these freaking true wetlands. I mean, would that be a reasonable conclusion?

Heath Hagy: We absolutely are. So last week, the National Wetland Inventory status and trends report came out. Where the fish and Wildlife Service looks at, I don’t know if you’ve looked at it yet, but shows changes in the last 10 years for wetlands. And there were some similar themes as what we’ve had in the past. We continue to lose palustrine wetlands, emergent wetlands, those are essentially, more often than not small and vegetated wetlands that are better for ducks, better they provide more food, so on and so forth. We actually have gains in some categories, some of the big open water wetlands. So those big open water wetlands are actually going to be better for things like scaup and canvasback and worse for things like mallards and pintail, green winged teal, so on and so forth. It’s just a complicated story, but you’re exactly right. That habitat is going to interplay. And for Canada geese and those reservoirs, they probably been a good thing habitat wise, right? So those birds have shifted to use those, or at least they’ve shifted to them, the water is not limiting. If that make sense.

Geographic Concentration of Wintering Waterfowl in the Mississippi Delta

One is down around Belzoni, where you’ve got this big concentration of former and existing catfish ponds. And all of those former catfish ponds are sitting in some form of wetland habitat, moist soil habitat, and it is attracting ducks leaps and bounds, as compared to other parts of the delta that have changed drastically in the last 20 years.

Ramsey Russell: Well, likewise, mallards and pintails, if they’ve got big reservoirs that they can stand on or swim in and then open agriculture fields to go feed in, why would they fly south to go hit these little potholes in the deep south? These marshes in the deep south? Why wouldn’t they hang up north? See, I bring this subject up because I bring this up exactly because I’m just going to take the state of Mississippi. Mid-winter waterfowl counts, they post up the monthly where the ducks are. And for the past 20 years, the distribution of wintering ducks in the Mississippi delta has become extremely highly concentrate three geographic locations, and it ain’t flooded corn, it ain’t NGO corn piles. It’s freaking water. It’s surface water. It’s wetland habitat in those 3 areas. One is down around Belzoni, where you’ve got this big concentration of former and existing catfish ponds. And all of those former catfish ponds are sitting in some form of wetland habitat, moist soil habitat, and it is attracting ducks leaps and bounds, as compared to other parts of the delta that have changed drastically in the last 20 years. Does that make sense? And so I’m trying to apply that little bitty observation, that little thought of mine, the Mississippi delta, to the entire Mississippi flyway or central flyway.

Heath Hagy: That’s exactly right. When you get state to state, some of that stuff becomes so important. You think about, you know, what the fall tillage and what the field preparation for cotton looks like versus corn or rice preparation some are much more amenable to short term flooding or even wholly managed water than the other one. And so you get these areas that are historically had a lot of wetlands, a lot of seasonal wetlands, even farm fields that would hold water in the winter that now don’t, because agriculture practices have changed, drainage practices have changed. And so it’s not just about climate, it’s not just about something going on in the north. It’s also about when you get within a state, how those things have changed. And look, there’s a lot of people through, not just states and the federal government doing waterfowl management, a lot of private individuals doing it out there. And I can’t make a conclusion on that because we don’t, despite what some people might say, we don’t have a database that tracks that. We don’t have any idea how much of that is out on the landscape, or at least not a good idea on landscape. But anecdotally, boy, sure seems like it’s increased with the wetland reserve program and conservation Reserve program and lots of federal and state programs to implement conservation on private land. There’s some wonderful and relatively new, huge wetland complexes in areas like you just pointed out, in those areas in the Mississippi Delta. They probably hold a lot of birds and maybe more than they did historically. And it sure seems like there may be some concentrations that don’t mimic where they used to be.

Ramsey Russell: Well, to your point, we interviewed Nick Masto recently, and I know you’re familiar with his research, and I cannot believe that this is an exception. When he mentioned that habitat is expressed in pure kilocalories, energy for a duck, that 70, some odd percent of it in West Tennessee was on private land. So 72%, let’s say, of how a duck makes his living is on private land in west Tennessee. And probably it’s not a far reach to say throughout the whole United States is sitting on private land, duck habitat is sitting on private land. And let me jump back about why you all did this research, because it’s important to how our continental populations of waterfowl managed. If they’re migrating differently and distributing differently, it could call for different management in the future. Question I’ve got, and I know that mallard ducks, mallards are a driver in a lot of the adaptive harvest management and practices right now. The Atlantic flyway went to more of a multispecies model. Is it possible that as these trends continue, that it might be better, could be better to or possibly an option that throughout the Mississippi, central and Pacific flyways, those begin to evolve to more of a multi species than just a Mallard model.

Heath Hagy: This is a good time for a disclaimer. I am not involved.

Ramsey Russell: I know you’re not. I’m not trying to try to paint you into a corner, I was just thinking out loud here.

Heath Hagy: That’s right. No, I don’t mind telling you what I know just with that disclaimer. And I think you’re aware, and some of the listeners may be aware, too, that our harvest management folks in the service, in collaboration with a bunch of great folks in the flyways, through the flyway council technical sections, are looking at all those things right now and moving in that direction in many cases. And so what I think we’re just talking about is the formal multi stock management in the Atlantic flyway. But those conversations are being had and the other flyways for things like that. And they’re already, AHM is already adapting. They’re already changing. They’re already making some changes based on the best science that we have and sort of looking at other harvest models for, for pintail and others. And so that’s probably where I should stop. But they’re certainly looking at that. And to your point, is it possible? Absolutely. Anything’s possible. Right now they’re following the best science that they have, but that doesn’t mean they’re just sitting and waiting on something to be better, we’ve got a lot of smart folks in the service, and it’s state agencies, through the flyway councils that are thinking about all those things right now. So great question.

Ramsey Russell: Yeah. And if we move into more of this climate change, this changing landscape, this change in waterfowl migration, this change in waterfowl distribution, you all brought out a really good point in some of these papers about how – somehow going to have to, traditional conservation efforts may have to evolve beyond just the modeling stuff that you’re not involved with. But, I mean, boy, I tell you what I read is that duck hunters in the southeastern US, this is mind blowing. I know, there’s a bunch of duck hunters down here listening. Duck hunters in the southeastern United States account for 1/3rd of all waterfowl hunting related expenditures in the United States of America. That is mind blowing. That’s some serious duck hunting going on down here in the deep south.

Heath Hagy: That’s right.

The Importance of Funding the North American Management Plan

Historically, traditionally, waterfowl hunters have sort of borne the weight of waterfowl management, right?

Ramsey Russell: But it’s not just okay, it’s all this money. It’s how that money goes into the North American management plan. Can you elaborate on the importance and why? Now, here’s where I’m getting at this heath. I’ll lay it out there flat. There’s not a duck hunter listening, a not duck hunter in the world, myself included, that would not like to pull up to a boat ramp tomorrow morning and look around and go, I got the whole place to myself. I mean, we all want that, you know?

Heath Hagy: That’s right.

Ramsey Russell: But when we start talking about 70 some odd percent of habitat, as much as 70 some odd percent of waterfowl habitat being on private property, I would just venture to guess that if, be careful what you wish for. If a lot of duck hunters quit, it’s not going to be the guys at the public boat ramps that quit, it’s going to be the private landowners. It’s going to be the guys that are spending a lot of money to impound 6 impoundments to go shoot ducks. They’re going to say, well, heck, I don’t want to spend as much money anymore. And what’s going to happen if all that private land management, we’re not talking flooded corn, man, we’re talking moist soil management, we’re talking some form of moist soil management or something going, all this habitat begins to shrink on private land, then what have the ducks got? You see what I’m saying? It presents a real problem. And what’s going to happen if we lose half our financial base in the United States that is driving the North American model for management for smart guys such as yourself and US Fish & Wildlife service and Ducks Unlimited and Delta Waterfowl, what happens if that funding dries up? Where do states get their budgets to manage for these waterfowl we so love?

Heath Hagy: Yeah, I know that that is a hugely important point. Historically, traditionally, waterfowl hunters have sort of borne the weight of waterfowl management, right? Not just, locally. So, yes, a number of state agencies they may be primarily funded or funded in a large degree by license sales. But also, you think about the state duck stamp or the federal duck stamp, a lot of that funding goes not only within the state, but goes to breeding grounds to sustain waterfowl populations. And we can’t manage of migratory species that can move a couple of thousand miles in a week, which most of our ducks can. We can’t manage those all in one place. And so that’s why that model where essentially it’s a crowdsourced model. We’re distributing that funding. Crowdsource model. We’re distributing that funding base all across our waterfowl hunters, and we get funding from other places as well. That’s hugely important. And a portion of that money, especially of your federal duck stamp, that goes to areas in the breeding grounds, not so that people in North Dakota or South Dakota or Saskatchewan or wherever, can primarily shoot ducks there. It’s to produce the ducks which then come south in the winter. So that’s a hugely important component. So it’s not just for hunting license, it’s not just for management on your local WMA, those hunting licenses, those state duck stamps, those federal duck stamps, that’s hugely important to sustain habitat, sort of that core of habitat so that birds have some place to breed and then migrate through as they distribute across the landscape in fall, winter, and spring on the way back up to breed.

Ramsey Russell: Unlike white tailed deer or cottontail rabbits, waterfowl are a continental resource. And I mean, we’re talking clear up to the boreal forest of the Arctic, clear down to the Gulf coast or in the instance of blue winged hill, far beyond, down into Central and South America almost. I mean, that’s a continental resource that takes a continental effort. And you’ve got so many moving pieces that you got to control from where they breed all the way to where they come, down to the deep south, all the way back up. That’s a huge obligation, isn’t it?

Heath Hagy: It is. You made a great point earlier about how important private land is. And that’s not just a breeding ground area. I mean, a wintering ground area. A large portion of waterfowl are produced on private areas in the prairies in Canada, most are in the US. So we won’t overcome this issue just in the federal government or state governments. It’s the burden of producing waterfowl every year really lies on this complex of state, federal, and then mostly private lands throughout the US.

Ramsey Russell: Heath, I sure do appreciate you coming on and explaining a lot of stuff. The best we can do is control the controllables. And there’s so much that we can’t control. We can’t control warm winters, or where migration distributes. But we’ve got to, the point I’m going to end on is what the topic we just ended, we’re all in this together. The hunters are putting their time and their money, private land and public land through our Pittman Robertson expenditures and everything else. We’re putting everything we’ve got into this continental resource and thank the good Lord almighty that in the United States of America and North America in general, we’ve got state and federal agencies and NGOs hard to work with us to keep this resource viable and keep it around for our grandkids.

Heath Hagy: Absolutely.

Ramsey Russell: I really appreciate you coming on to wade through some of these complex topics today. I always enjoy seeing you. I can’t believe – I’m going to end on this note, though. How’s a southern guy managing up there in North Dakota so far?

Heath Hagy: We’re making it. It’s been a mild winter, which is good for my wife, not so good for the ducks coming up this spring. It’s been a mild and dry winter here in Bismarck and so unfortunately, unless something changes, we’re not going to have the best, the prime wetland conditions for our breeding ducks coming up. But like I said, my wife appreciates not having 50 inches of snow on the ground when moving to Bismarck, North Dakota, in the winter.

Ramsey Russell: But have you bought a snow shovel yet?

Heath Hagy: We have it. We have a snow shovel and the 10 year old has been trained extensively on it.

Ramsey Russell: Well, there’s nothing we can do to control the wetlands conditions right now, and I’m afraid that it’s going to get worse before it gets better. It’s going to take a Noah build the arc flood to bail us out this year, isn’t it?

Heath Hagy: Yeah. We’re definitely dry in the breeding areas and a lot of the breeding grounds are dry this year. So a lot of us will be looking forward to seeing what the breeding population estimates look like when they come out later this summer and seeing how habitat conditions develop. But it’s not looking optimal at the moment, I’ll say.

Ramsey Russell: Right. Heath, thank you very much. And folks, thank you all for listening to this episode of Mojo’s Duck Season Somewhere podcast. It’s a lot to think about, isn’t it? See you next.