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Ep. 534 – Species Profile: The Mallard · Ducks Unlimited Podcast

• Chris Jennings: On today's show, we are going to do another species of waterfowl. And today's the most popular duck in North America, probably the most populous duck in North America, the mallard. Joining me today is Dr. Mike Brasher, my co-host. Mike, how are you? I'm doing well, Chris. How are you doing today? Awesome. I am ready to talk about the mallard. So, you know, just with everyone is so familiar with the mallard. So, you know, when we first started talking about doing these shows, it's one of those deals where I'm like, man, I just don't know if we can you know, talk about just the mallard for 45 minutes or so, but… Yeah, I don't know if there's anything to say about it. Yeah, right. But then you walk in with a stack full of notes. And so this is going to be great. So Mike, go ahead and give us a quick introduction to the mallard. Just kind of a real brief intro about the species and then we'll get into the weeds. Mike Brasher: It is, as you say, the most populous duck in North America, actually the most populous duck in the world. It is a Northern Hemisphere species, at least originally. And one thing that I'll just say here, we're not going to get into all the taxonomic relatedness, phylogenetic relatedness of this species. We actually had Dr. Phil Levretsky on an earlier episode talking extensively about this, and this is kind of his area of expertise. So, kind of go back to some of those episodes if you want to learn about the phylogeny of of the mallard but it is historically a north northern hemisphere species occurred across the northern hemisphere in north america and europe but then of course through a variety of introductions they're now pretty much found on every continent except antarctica across the globe so uh yeah we can get into harvest statistics and where it ranks and all that kind of stuff but pretty much anything that we're going to say about the mallard is that it's going to rank at the top in terms of how intensively it's studied. It as the basis for much of what we know about waterfowl ecology and habitat relationships. It's just, it has been the star, you might say, if we want to anthropomorphize here a little bit, throughout the waterfowl world and waterfowl literature for many, many decades and continues to be one of the most popular and well-studied duck species, bird species, quite frankly, all across the world. Chris Jennings: Yeah. And, you know, it's, it's so common that, you know, things that we do every day, even like emojis for iPhone, you know, if you put type duck in there, it actually generates a picture of a mallard. So for any of our listeners out there who are not aware of what that mallard looks like, you know, just a, just an FYI, it's that green headed duck. And I know you mentioned you didn't want to get real in depth with this, but I'm going to let you kind of share a little bit about the taxonomy. Mike Brasher: Yeah, and this kind of goes to this well-studied group of birds, kind of called the mallard complex, the mallard clade. And yeah, I'm not going to get too deep into it, because quite frankly, I am not a taxonomic expert. That's where our good friend Phil Levretsky comes in handy. But here within North America, we can certainly touch on the most obvious ones. Mallard, you know, that's the… That's where we start, an American black duck, close relative to that model duck, also close relative Mexican duck. It was recently recognized as a unique species by the American Ornithological Society. And then if you go over to the Hawaiian Islands, we have the Hawaiian duck and the Laysan teal that are in that Mallard complex. And then you kind of get overseas and pick up a few others, four or five others, depending on how you want to look at the taxonomy. But I'll stay away from that for right now. We'll just kind of stick to the, those in North America and over in Hawaii. Chris Jennings: Yeah, and we can get Phil back on at some point to maybe, you know, get even more in-depth than we already have with the shows that you did a couple seasons back. You know, and one thing that you mentioned is it is worldwide. I mean, the Mallard is, you know, distribution-wise, it's pretty much everywhere. And so, you know, let's talk about their distribution and how it's specific to North America. Mike Brasher: When we talk about the distribution of this bird in North America, I think the first thing we have to do is acknowledge that people are going to see many, many mallards in urban settings. And there's a variety of reasons why that is the case. I mean, they're just fundamentally very well adapted to some of those urban environments. They've just exhibit tremendous flexibility in their diet. their habitat needs, their nesting needs. They can nest anywhere. You can find them anywhere. So, a lot of the people that see ducks in urban environments are going to be looking at mallards. And so, just kind of keep that in mind. We'll set those urban environments aside right now, just accepting that you're going to see a lot of mallards in urban environments. When we look across North America to their primary breeding habitats within, let's say, just the free ranging, the more natural settings, the heart of their breeding range is going to be the prairie pothole region of the US and Canada. But of course, they breed all across the northern US and all across Canada into the boreal forest. About the only place you won't find them is on the tundra. They do nest on the coastal plains in Alaska. There's sizable populations of mallards, breeding mallards in California, Oregon, Washington, Interior British Columbia, of course the Great Lakes states, all across the northeastern U.S. and then into eastern Canada as well. They are widely distributed. across the northern tier of North America. Chris Jennings: And I'm sure that that's the reason for their abundance, too, is they're, you know, really prolific and opportunistic is probably the better word. You know, they'll take advantage of any type of habitat. You know, for now, granted, they have, like you said, they have their preferred in the PPR, the Prairie Pothole region. But we just had Fritz Reed on not too long ago, and he was talking about, you know, the large percentage of mallards that are actually raised in the boreal. You know, and that's one thing that I think, you know, maybe our audience overlooks sometimes that, you know, those there's a ton of mallards coming from up there, up further north. Mike Brasher: Yeah, depending on the year, like during a dry year such as this 2021, if we were to look at the total estimated mallard breeding population kind of in the east, in the western US and Canada, about 70%, I would say somewhere between 60 and 80% of that mallard breeding population is going to be in the prairie pothole region of the US and Canada. Maybe, yeah, maybe more like 60 or 70. 80 might be a little bit high whenever you factor in the breeding populations in California, Oregon, and Washington. But yeah, so that's, it's the heart of their breeding range and that is why it's one of the reasons why it is so important for all of our conservation efforts. Chris Jennings: Absolutely, you know, you kind of flirted with this, you know, the breeding, breeding range here. Let's get a little bit more into kind of the ecology of it because some people, even like you mentioned, people will see, you know, or these urban ducks are probably what some people see most, more than anything. But we always get a ton of questions about those. Just, hey, you know, how long are they sitting on the nest? How many eggs are there supposed to be? So, let's kind of get into that, like, just their actual, like, the functioning of their nests, how the process works. Before we get in the actual nest, you know, let's even talk about, and now you did your PhD research. That would be my master's. Master's, okay. You did that on mallard breeding ecology, did you not? Mike Brasher: I did, specifically male mallard breeding ecology. Chris Jennings: Yeah, so what exactly, how does this process start, and kind of let's go through that process through the whole breeding cycle. Mike Brasher: Well, so let's back up to fall. That's when things really start gearing up in anticipation of breeding the subsequent spring. Mallards, in contrast to other species that we've talked about, like blue-winged teal, mallards are a species that will that will pair fairly early. They are seasonally monogamous, as we refer to them, which means they form new pair bonds each year. But once they have formed those pair bonds, the male and female will remain intact or will remain together. until the female is far along in incubation or otherwise one of the pair members dies for whatever reason. So, seasonally monogamous, those pair bonds begin to develop in the fall. Somewhere by November, let's say by December, we're probably looking at about 70, 80 to 80% of the mallard females being paired. Mallards, like most species of ducks in North America, exhibit a male-biased sex ratio, more males than females in the population, which means that there are going to be some males that will not find a mate. But yeah, they form their pair bonds in the winter. And then once they travel back north to breed in the prairies or the boreal forest or wherever it may be, the hen will find a suitable nest site, typically in some type of upland area. They are upland nesting ducks, like most dabbling ducks in North America. However, mallards, being very flexible in their nest site selection, They will nest over water. They can kind of construct a little platform actually over water out of grasses or emergent vegetation and build a nest in those situations. They also nest frequently in human-provided, human-constructed structures. Nest tunnels would be the most common type of nesting structure that people would find a mallard, hen mallard nesting in. And they just nest in pretty much every place that you could imagine whenever you look at some of the nesting studies across the years and they identify preferred nest site or primary nest site selection or however they characterize it. A lot of times they will find mallards most often in odd areas. They kind of describe them as odd areas, shrubby areas, long fence line. Flower pots. There's been some of that too. We found some in the crooks or crevices of trees, you know. They're just, they will nest pretty much anywhere they find a site that they deem suitable. That is quite frankly, to their advantage, and that's in stark contrast to other species like pintails, which are almost nest site specialists. And of course, there's a story behind with pintails about how that is sort of… One of the things that's causing their population troubles. But yeah, mallards are readily adaptable in terms of their nest site selection. And so the hen establishes a nest, creates a nest bowl, and on average, she will lay about nine eggs. Uh, that contrast with, uh, another species we've talked about, again, blue-winged teal, sort of the other end of one of these spectrums. So, mallards are about, you know, are a larger duck, about two and a half to three pounds. And, um, and yeah, they will average clutch size for first nest is about nine eggs. Now, the other thing about the nesting ecology of mallards is they are the most prolific re-nester, which means the re-nesting is basically the process by which after one nest is destroyed, the hen will initiate a entirely new nest. There's sometimes anywhere, well, the time between nests varies and it depends on a number of things. The stage at which the nest is destroyed, whether it's early in laying, if a nest is destroyed when the female is just in the laying process, a lot of times she will just pick up the very next day and start a new nest or sometimes you'll wait a day or two. But once they get farther into incubation and if the nest is destroyed, it may take a week or 10 days before they gear back up for nesting. But anyway, mallards are one of the most prolific renesting species. They can nest up to five times during years when there's abundant wetlands when conditions are good. Now in drought years such as 2021, it provides us an opportunity to talk about this and how it affects their ecology. They're not going to re-nest as often simply because they're going to assess the habitat conditions and in a drought landscape, they're going to be able to sense and detect a shortage of wetlands and whatever kind of calculus goes on in the mind of a duck to make those decisions, it happens and they will curtail their re-nesting quite a bit during the years when there are fewer wetlands. So, yeah, that kind of gets us to the average clutch size of nine. With each of those renests, the average clutch size decreases. And that rule, that's a general rule anyway, the later in the breeding season that a nest is initiated, the smaller the clutch size will be. Average length of incubation for a mallard is somewhere around 26, 28 days. Chris Jennings: What time of year are they typically getting up there to start this process? Mike Brasher: Yeah, good question. They, well, what I can tell you is whenever I was working on my master's research, we would arrive in, I would leave from Mississippi and we would arrive in Manitoba or Saskatchewan in late March. So, we would have to be there on site basically before the ducks arrived. Sometimes they would start arriving in very late March, but most often mallards are going to be some of the first to arrive. Mallards and pintails will be among the first to venture back north. They want to get an early start on breeding and they will typically get there in noticeable numbers in the first week or so of April and then they will start nesting in mid-April if conditions are right. Chris Jennings: I kind of wanted to just go back real quick before we move on into clutch size, because I'm sure we're going to get pretty detailed on this. But you talked about the initial stages of that breeding process, of that full breeding cycle. That's something that hunters, your average hunter out there, is witnessing throughout the season. It's something that we point out a lot when we talk about kind of tips and tactics deals, because you see these, you know, large flocks of Mallards early middle of the season. And then later in the season, as you get into late December, especially down here, you know, in the Mid-South area and the South, you start seeing pairs. You know, you're not seeing a flock of 20 or a flock of eight, you're seeing a drake and a hen. And that's the part of this process that most hunters have probably witnessed no matter where they're hunting. You know, they've probably seen that. So, I just wanted to kind of point that out before we move on to actual clutch size and things like that. So, what are these things doing the day they pop out? The day they hop out of the egg, you know, you've got, what, nine, possibly ten? Mike Brasher: Yeah, nine or, on average, nine, sometimes ten, sometimes eight eggs. That would be the terminal clutch size. And, you know, hatchability, one of the questions that, that researchers have, I mean, researchers have, have answered or asked questions and collected data to answer pretty much any type of question you can imagine. One of the questions is like hatchability. What percentage of the eggs in a nest will actually hatch or fertile? That percentage is pretty high. It's just kind of a little tidbit. Probably over 90, 95% are gonna be fertile. So, high hatchability is very rare that you… It may even be higher than 95%, but it's very rare that you find nests that go unhatched in most of your dabbling and diving ducks, wood ducks, and other… black belly or whistling ducks and other cavity nesting species may be a little bit different, especially when you have a situation where that nest is being parasitized and you have multiple females nesting in a minibox, you know, you can get massive clutch sizes, 20 and 30. Those are pretty rare. Yeah, they're rare, but well, it's not uncommon at all for those cavity nesting species to have more than, you know, 10 or so eggs. And in some cases, that's when you might find a number of eggs that go unhatched. But when we're talking about ground nesting ducks, over water nest, or dabbling and diving ducks that nest in uplands or nest over water, where their nests are harder to find as a general rule, and that parasitism is lower, with exception of canvasbacks and redheads. There are going to be very few instances where the eggs do not hatch. So, you're going to have nine or 10 ducklings or fewer if it's later in the season that will hatch. And again, all ducks are, all species of waterfowl are precocial, meaning that those young ducks, geese, or swan are able to, they have down all across their bodies, unlike the altricial young from passerine birds or most of the other birds that we're kind of familiar with, where when they hatch, they're naked. They do not have feathers. That's in contrast to the precocial birds, which are down covered. They are fully mobile. Their eyes are open. and they are able to forage and move independently without the aid of the parent. So, upon hatching, those little fuzzballs make their way to a wetland and, you know, they are kind of guided or taken there by the hen and they start trying to eat, trying to catch bugs. Chris Jennings: Yeah. And, you know, and that's the difficult part of, you know, this whole process is, those little ducklings are very, very vulnerable to just about everything out there. But one thing that I had heard someone talk about not too long ago was how vulnerable, and it might have been you, but I don't want to give you credit right now. The, how vulnerable those ducks, the days that they, you know, the day that they come out of the egg, they're very vulnerable to moisture and, and weather. Like if it gets really, really cold in the spring, they can, that can kill the whole clutch. I mean, it can. Mike Brasher: Yes, once they hatch, the brood. So, we go from a clutch of eggs to a brood of ducklings or goslings. And yes, during those first few days, and I forget exactly how many days, I want to say they have the ability to thermoregulate to some small degree pretty quick, maybe within a day or two. But then it's not until they're maybe a week or so old, that may be a little bit generous, they may get there around four or five days where they develop a greater sense of thermal regulation and they're able to kind of, they are a bit more resilient to those kind of adverse weather conditions. But during those first few days, absolutely. The hen has to brood them, basically meaning that at night or in otherwise inclement weather conditions, whether it be a snowstorm or rain, they will huddle under her. They'll find a place, a log or a dry area up in the vegetation and try to stay out of the eyesight and detection of predators and she will protect them from those elements by getting them to kind of stuff up underneath her feathers and under her wings and pretty neat little deal. So, yeah, she does brood them for those first few days. But then once they get to about a week or so of age, they can do a bit better job independently of thermoregulating. But absolutely, exposure is a common source of mortality for ducklings. Chris Jennings: And, and as we just kind of go through this process, we're actually going to, you know, follow right along with our little plan here, but it's just, we're actually just following along with the, the, the life cycle of a Mallard, which is cool. Um, how many days does it take for the, or months, I guess, does it take for them to be able to fly? Mike Brasher: So for Mallards, uh, from the time they hatch, it's going to require somewhere between 40 to 60 days for them to, you know, to be fully feathered and able to fly. Actually, they can typically, sometimes they can fly a little bit sooner than that, but, uh, but yeah, about 50 days, I'd say is probably a good average time to fledging after, uh, after they hatch. Chris Jennings: And how long do they stay with the hen with the mother, I guess, as they get older and grow and right before they're kind of preparing for migration, you know, by this time in the life cycle, you know, their their their job is to prepare for migration and survive, obviously. But so how long do they stay with their mother? Mike Brasher: They will, uh, it's not uncommon. I'm thinking back to whenever I was on up there in Canada, doing some, doing some of my research. It's not uncommon to find ducklings that you would think are able to fly that still have the, the hen around. So she'll, I suspect there's some variation around that. This is a pretty specific question that I'll confess. I don't know exactly, you know, what, what controls the length of time that a hen is going to stay with those ducklings. Um, but once they. It wouldn't be uncommon to find a hen with ducklings that are right near flight capability, but it also wouldn't be uncommon for a hen to kind of bugger off, you know, two weeks prior to that. So, the point is, she's going to stay with them for quite a while. Chris Jennings: What are these ducklings eating when they finally do get to a wetland? What are they keying in on to grow? Mike Brasher: No, it's going to be invertebrates of all different kind, whether they be aquatic invertebrates or little flies and midges that are emerging from the wetland and perching on the on vegetation. You've pretty much all of us have seen photos or videos of a little duckling jumping up out of the water trying to grasp a fly that's traveling overhead or that's perched on a piece of vegetation. But yeah, it's pretty much all invertebrates of various types there where they're trying to get those protein resources to help them grow their muscle, their feathers, and then all the other tissue that they need to grow and grow quickly. Chris Jennings: Yeah. And that's when the, like I mentioned, kind of the pressure's on. So what kind of transition into that? You know, they're trying to put on weight, preparing for the migration. This is not necessarily focused specifically on the ducklings in general, but just the mallard. What are they doing as they're preparing? This would be like, I would say maybe late summer, early fall, they're kind of preparing for that migration. What's their focus at that time? Mike Brasher: Yeah, so I'll come at this from several different angles. We'll talk about the different sexes. First, let's talk about the male mallards a little bit because we haven't spoken much about them, you know, once we get there to the breeding grounds. Like most, so I said earlier that they're seasonally monogamous. The female in ducks in North America, we have what's known as female biased parental care. Pretty much the female is the only sex that cares for ducklings in ducks here. And so basically what that means is that the male's responsibility for any kind of care of the ducklings I mean, it's non-existent, but their parental care responsibilities begins to wane as the female progresses into incubation. And so, what my study actually did was I had radio-marked males as well as the radio-marked female pair. And so, I knew if the hen was nesting and then I was tracking the male and actually collecting visual observations of that male. And so one of the questions that we were answering, trying to answer, is this very one of at what point do the males depart the breeding ground, either leave the female and go seek other breeding opportunities, or completely leave the breeding site, the breeding region, and go ahead and start molting? Chris Jennings: Yeah, I just want to point out that you know, most of the world just looks at ducks, but Dr. Mike Brasher collects visual observations. Well, that's right. That's all we did. Collect visual observations. I was just looking. You know, I'd look at them. No. We observe, and yes, that's right. That's perfect. No, that was cool. But, you know, in your studies there, were you learning that maybe that male hung out a little longer than you originally thought? We did. Mike Brasher: Our study was, I, that was probably one of the takeaways that a lot of times now I read species accounts of the mallard and they will, a lot of times you'll find where they describe them, the male departing or that pair bond loosening once the female gets to incubation, one or two days of incubation. What I actually found is that, That male, in most cases, the male mate stuck around in proximity to where that hen was nesting, well into incubation, two to sometimes two and a half, three weeks into incubation, which is a bit unusual or at least unexpected relative to what we had been previously found, and so I don't exactly know If there was something driving that, maybe it was an exceptionally wet year, they had good wetland conditions and the male was kind of gauging whether he thought there was going to be additional re-nest opportunities. Again, what goes on, the calculus that goes on in the mind of these ducks is a bit uncertain, but we did find the males hanging around and being available for those re-nest opportunities in pretty much every case. In any of the, at least for the males, the pairs for which we had that male mate radio marked, I think there may be only one or two instances where we observed the female pairing or mating with a male other than her original mate for a subsequent re-nest opportunity, if that makes sense. In every case of those re-nest opportunities, it was the original male mate that she was with, is basically what we found, which was pretty cool to see that. So nevertheless, though, once they get about two to three weeks of incubation, that male starts ranging a bit more widely across, in our case, the study area. And by widely, I'm talking five to 10 miles. Sometimes we'd have to go to search for him. But then once she gets even farther into incubation, and certainly once she hatches, that her clutch of eggs, the male is buggering off doing other things. And pretty soon, a lot of those males depart the breeding area and will end up traveling to some more permanent molting lakes where they will drop their flight feathers and go through the molt. And yeah, so that's what the males do. And then females, if they're successful hatching a clutch, they, of course, do transition into brood care. And they was not uncommon for females, we think, to actually molt their wing feathers on the breeding grounds where they have been raising that brood. Now, if they nest early enough and or if their nest is destroyed or repeated nester destroyed, then they will eventually kind of give up and go on to some of these molting lakes. But it's not uncommon at all. we don't think, for some of those females to be dropping their flight feathers and molting there in proximity to, you know, the area where they actually nested. So, that's all going to be happening in late summer and then they, mallards and some of the other duck species that don't migrate as early as bluing teal, they will transition to this this sort of staging period, as we refer to it, where they are kind of hanging out, getting fat, replacing their flight feathers, and preparing for that southward migration whenever they feel the urge to do so. Chris Jennings: Is mallard one of those species where the young of the year quickly become, you know, that within that same year, you know, is a hen mallard going to be expected to raise a rood and nest that same year? Or is it one of those species where it's two years old, it'll do it? Mike Brasher: Yeah, all dabbling ducks will nest and are capable of breeding. in their first year of life. And that basically means the following spring. It's like, we're not talking about them attaining flight and then being able to breed within three months of them having hatched. The following spring, right. They do breed at one year of age. Mallards, blue wings, shovelers, pintails, black ducks, all those species are that way. And in most of the diving ducks, most of the diving ducks are going to be the same way. Chris Jennings: And then, you know, let's, let's talk about migration. We're talking about, we got all the way up to staging. And I think that's kind of the quintessential mallard image in people's heads would be, you know, these large flocks of migrating mallards or mallards in the snow, you know, something like that, where, cause they're, they're actually a really hardy bird. Mike Brasher: Apparently Mallards don't migrate anymore, according to social media. Chris Jennings: Here we go. Yeah, no, I mean, I think that that's, you know, not that specifically, but I think one thing that makes the Mallard so exceptional is, the fact that it can handle some pretty cold temperatures. It can handle, you know, a little bit of snow and a little bit of ice. And before they, you know, they're hardy enough that they really try and stick it out. And so in that process, how much are they having to pack on in that staging area to make sure that they can make the flight? Because some of these birds are wintering, you know, as far south as Louisiana, you know, Arkansas. You know, these are, you know, Texas, California, Southern California. I mean, that's out West, but, you know, what are they doing to pack on this much weight? What kind of foods are they eating? How are they, how are they approaching that, that next stage in their life? Mike Brasher: You're starting to touch on a couple of, a couple of really intriguing questions and that relate to, to things that we observe with regard to Mallard migration. There's, there are, it's almost as though there, there are some, Mallards, as you described, there will be Mallards that will be in Louisiana. They will have already migrated to Louisiana by late October, maybe even earlier in some years, early November. And meanwhile, there are still Mallards left hanging out in North Dakota. Which mallards are those, you know, the ones that migrate early, regardless of what weather conditions are and how cold it gets, how early it gets cold, versus those that really hang out at northern latitudes despite severe winter weather? What causes those differences? We really don't know. And it's actually a pretty intriguing question that I think is gaining a little bit more attention, or at least it's been talked about a lot now as we are trying to do a better job or trying to learn more about the migration dynamics of mallards and other species as well. But certainly, mallards being one of our largest duck species, our largest dabbling duck species, It is able to pack on a lot of fat. It has a highly flexible diet. It can basically eat anything from invertebrates to corn or rice or wheat or peas. And that gives it a ton of options. Fish, peons, peanuts, acorns, anything. There's very few things that mallards will not will not eat and cannot derive some energetic or caloric value from. But during that staging period, they are trying to pack on calories. They're consuming carbs. That's what they're after. And so that's going to come in the form of peas, wheat, barley. Those are the ones, I'm missing some, well, corn on the landscape as well. Rice, you know, farther south in some of those landscapes, but I'm thinking about up north. I'm thinking about, mainly I'm thinking about Prairie Canada, and there is some corn that's making its way into Prairie Canada, but traditionally when you think about large flocks of mallards that are out across that landscape foraging, feverishly to try to pack on that fat, we're talking about peas, garbanzo beans, you know, wheat, barley. Those are going to be some of the big ones. Chris Jennings: Yeah. So, you know, that migration, the big jump, then they're coming down to the wintering areas. How does their food change? Will the food resources change? And what are these ducks doing once they're on the wintering grounds? Mike Brasher: I think it's probably fair to say that we don't see noticeable changes in the, in like the type of nutrients that ducks, that mallards are seeking until the following spring. During fall, winter, And prior to spring migration, it's really carbs, seeds, acorns, agricultural grains that they are after. Now they have to supplement that obviously with invertebrates and other forms of plant material to obtain their essential nutrients, minerals and nutrients, just like we all have to have a balanced diet. Mallards can't live on, quote, bread alone either. And by the way, we should not feed bread to mallards even in those urban settings. They'll be fine. They'll be fine people. They'll survive. We don't need to feed them bread. So yeah, we don't see changes to their diet until spring. And that again relates to them kind of gearing up to gearing up for that breeding season egg formation. Actually, now that I say that, and I kind of listen to myself talk here, one of the things that I'm leaving out in terms of what they go through during winter is molt. They do go through a molt during winter. Females will, and the males do to some extent, and so then they, so as they're going through that body molt, not a wing molt, but a body molt, they will have to acquire protein to replace those feathers. So, they do seek out protein in the form of invertebrates at that time of year as well. So, I want to make sure I didn't kind of goof up there and forget about the molt that occurs during the winter as well. Chris Jennings: Yeah, and just to clarify that, you know, the body molt is actually the body feathers, and they transition new feathers at that time, but they can still fly. Yes, absolutely. And I just wanted you to clarify that for our audience that, you know, when you think of MOLT, the first thing that especially pops into my head is they go flightless. Mike Brasher: Yeah, right. No, this is a, they drop their flight feathers only once per year. They go through, Oh, I'm kind of off guard here. I'd have to stop and think about this to get it correct. So I'm just going to say they go through a couple of body molts, a couple of molts of their contour feathers, their body feathers each year, and the males and females differ a little bit in the timing of those molts. That's an episode, that's a conversation that we need to think a little bit more about and have someone on that can speak to that, those different stages of mold and how they vary among species. And, you know, there are some that we, there's some thought that even that maybe ruddy ducks might go through a second wing molt. on their wintering ground. So, anyway, there's some interesting things to talk about with regard to getting into the details of molt, when it happens, the different types of molt and so forth. But yeah, that's why whenever you go out into a wetland during the winter and you see all these feathers on the water, well, they're going through that body molt during the winter, the females will be. Chris Jennings: And then, you know, at that time, you know, as we get into fall and winter, that's when waterfowl hunters are out there chasing these birds. And being the most abundant duck, really these things are making up a majority of a lot of people's bags. And I just want to say, there are some areas in the country that don't harvest near as many mallards as others. But what makes some of those states different from each other? As in, you know, West Virginia is not going to harvest near as many mallards as Arkansas, obviously. But what is it about that habitat use during the weaning area that really attracts mallards to these high abundant states. Mike Brasher: So you love to ask those, what is it, why questions, which puts me on the side of having to provide a good explanation. So let me just say there's probably a number of reasons behind this. Let me start by saying that when we look across the four flyways, mallards are most abundant in the Mississippi flyway. And if you roll back the hands of time, that's going to be related to, and quite frankly, a lot of the patterns that we see now are going to be a reflection of the uh, sort of longer term historical patterns of migration and, and, um, uh, and habitats and how they've occurred across the landscape. So when we kind of back up a hundred years or so and look at where the habitats, wintering habitats occurred that we would have expected Mallards to use, the lower Mississippi Valley, the lower portion of the Mississippi River Valley is, that was it. You know, those flooded bottomland hardwoods when the White River, the Cache River, the Mississippi River got out of its banks, flooded those bottomland hardwood forest and made accessible all those acorns and other grasses and whatever, all sorts of other food resources that Mallards would just gobble up. That became the heart of, and has remained so, quite frankly, the heart of the winter distribution of mallards. Now, you can look to the Gulf Coast of Louisiana, Texas, Texas Panhandle, the Playa Lakes region. Lots of wetlands there. Pretty much anywhere you find wetlands, you're going to find mallards, and you're going to find mallard abundance is going to be at a regional scale, kind of correlated with at least the historical abundance of those wetlands. Out in California, a good chunk of the mallards that they harvest in Central Valley, California, are going to be locally produced. You've got mallards that are locally produced in the Great Lakes that make up a good portion of their mallard harvest. The same is going to be the case in the Atlantic flyway, the Northeastern US, where you get some mallard production. Those birds disproportionately contribute, like on a percentage basis, if you look at the birds produced in the Northeastern US, the majority of those are going to be harvested in some of those local states. Now, they do continue to migrate on farther southward, but they're disproportionately important to those areas where they are produced. The distribution of mallards is going to be a reflection generally of the distribution of the habitats and the food resources that they are after. And that really leads us to the Mississippi Alluvial Valley as the stronghold. So. And you have some harvest numbers too. I do. I do. We can look at harvest and it's going to reflect that same distribution and abundance. And so not surprisingly, about half of the mallard harvest on average occurs in the Mississippi Flyway. And it's been that way for many years and continues to be that way. When you look across the entire US, I don't think these numbers here account for a harvest that occurs in Canada. Look across the entire US on average over the past 20 or so years, we've had an average harvest of about four and a half million mallards. I think we've had a few years recently here where the number's been lower than that. But on average, we're looking at four to four and a half million mallards harvested. And half of those are going to come from the Mississippi Flyway. About 20% of that is going to come from the Central Flyway. Another 20% is going to come from the Pacific Flyway, including Alaska. And then you get about 10% or so from the Atlantic Flyway. And if you look at the importance of mallard in the overall harvest of ducks, on average, they're going to account for about a third of total duck harvest. It's a lot. It is. One species accounts for about a third of the total duck harvest. Now, part of that is because we have I mean, it's a robust population size. If you look continentally, you're probably looking at a breeding population size somewhere around 10, 11, 12 million on average. And that may be even higher in some years. And yeah, so it's an incredibly abundant duck. respectably high bag limits, at least during the liberal seasons here over the past 20 or so years for that species. And it is a, I mean, it's just a great duck to hunt. The way it decoys, the way it responds to calls, the way it responds to decoys, at least if, you know, they don't always respond to my calling or to my decoys. So, I need to work on that. So, not all mallards are the same, or maybe it's not all hunters are the same. I'm not sure which is the case. Chris Jennings: I think there's something special to be said about, you know, it is, it's ironic that it is the most abundant species and it is also, you know, the most harvested species, yet it still holds such a, you know, I guess a high stature. Mike Brasher: That's right. The appreciation isn't worn out, isn't eroded by its abundance or by its popularity or the, not popularity, but yeah, it's just, it's commonness. Yeah. Chris Jennings: And there's something special about that green head on blue sky days. You get that white underbelly, the sun shining. It's, it's something special about the Mallard. Yeah. Before we get out of here, let's do quick rundown on just conservation concerns, obviously with the abundance and with the prolific lifestyle that these things live, kind of pinpoint some real conservation focus that Ducks Unlimited Science is taking a look at right now. Mike Brasher: What I need to do here first is talk about three different breeding stocks of mallards because that's how we think about some of our conservation concerns. In North America, mallards can be subdivided into three breeding stocks. One is a Western stock of mallards that will include mallards in Alaska. Interior British Columbia, Washington, Oregon, and California. There's the mid-continent breeding stock of mallards. That will include mallards in the prairie provinces of Canada, the northern, the prairies of the US, the western boreal forest, the Great Lakes states. And then there's the eastern stock of mallards, eastern population of mallards, which is going to include everything pretty much east of the Great Lakes. Major production areas will include the northeastern states down to about Virginia. You're going to find a few birds south of there, but Virginia is about as far south as you can find appreciable numbers, at least in those wild settings. And then eastern Canada as well. Those three stocks of mallards are how we in the waterfowl management community manage mallard populations. Western mallards I've been doing pretty good. I don't have population numbers broken down by those different stocks. What I can do, I think I can remember these ballpark wise in terms of like the mallard average mallard breeding population size across those three stocks. If we, for the mallards in the Atlantic flyway, Eastern mallards, I think we're somewhere around one to one and a half million on average, if we look into The mid-continent population, that's, of course, the largest population of mallards there, anywhere from, you know, nine to six or seven million, depending on habitat conditions, whatever. But typically you're looking at around nine million, at least here in recent years. So, for that Western mallard stock, I think we're looking at somewhere around a million mallards, somewhere in that neighborhood. Most of them are in that mid-continent. I may be a little bit off on some of those numbers, but relatively speaking, it's going to be in the ballpark. The mid-continent mallard population is the big one. And so in terms of conservation concerns, Western mallards are doing pretty well. Well, they're doing fine. There's no indication of any issues with their populations right now. And then in the mid-continent population, No issues there. Like, there's no pressing, like, population decline that we can't necessarily understand. Now, if you want to look more regionally within that mid-continent population, you can go to the Great Lakes states. And there are some issues there, some concerns with declining mallard populations in, you know, among that sort of subset, that breeding subset. And we're actually involved in some research now. Michigan State University is a partner in this research using some satellite transmitters to try to get a handle on what's going on with, uh, with Great Lakes Mallards as a subset of that mid-continent population. And then you get into the Eastern Mallard and that's, that's its entire kind of issue of its own. We've seen also population declines over the past 10 or so years, um, for Eastern Mallards. And we began to touch on that a little bit with Phil Levretsky a couple of years ago. He was looking at the genetics of what's actually happening there with the, with eastern mallards. So, declining population size among eastern mallards, as well as some really intriguing genetic stuff of game farm mallards, maybe, you know, kind of having a, becoming more prevalent in that eastern mallard population. There's also some questions about differences in productivity between mallards nesting in the US versus mallards nesting in Canada. It's like we're seeing these population declines. What's driving it? Is it harvest? Is it reproduction? And then, are there differences in reproduction between birds produced in the, or birds breeding in the U.S. and birds breeding in Canada? So, you know, when we look at mallards, the Great Lakes, as well as the eastern mallard population, the ones for which we do have some concerns, some legitimate questions, and we're trying to get at those through some targeted science. Now, in terms of overall conservation, like I said at the outset, mallards have been the basis for much of what we know about habitat relationships between ducks and wetlands and upland nesting areas. Now, through the years, we've studied individual species and learned a whole host about or learned a lot about those other species, but mallards continue to be a really good proxy for kind of what's going on with those areas or at least for the habitat requirements and the type of work that we need to be doing to maximize recruitment and then breeding season survival. And so that they have helped shape in a major way a lot of the conservation efforts that we pursue up there in the prairies. Chris Jennings: No, that's awesome. And it's, this has been fantastic. I mean, we've, you know, like I said, at the outset of the show, I was concerned we'd be able to get, you know, this long, but we could probably go even longer. Mike Brasher: I'll probably go back through here and we'll listen to it. And I'll, you know, say, oh, well, shoot, we didn't, we didn't talk about that. We didn't talk about that. That's right. We could have said this, or maybe you might even say, oh, Mike, you screwed that up. Chris Jennings: Well, if that's the case, we'll do Mallard's part two pretty soon. Mike, this has been great. It's been awesome. I hope our listeners learned something today about the Mallard. But thanks for joining me. You bet, Chris. My pleasure. I'd like to thank my co-host, Dr. Mike Brasher, for coming on the show and talking about Mallards with us today. I'd like to thank Clay Baird, our producer, for putting the show together and getting it out to you. And I'd like to thank you, the listener, for joining us on the DU Podcast and supporting wetlands conservation.