Ep. 715 - Species Profile: The Mallard
Can we do a mic check, please? Everybody, welcome back to the Ducks Unlimited podcast. I'm your host, Chris Jennings. I'm your host, doctor Mike Brasher. My name is John Gordon.
VO:I'll be your host. And I'm your host, Katie Burke.
VO:Welcome to the Ducks Unlimited podcast, the only podcast about all things waterfowl. From hunting insights to science based discussions about ducks, geese, and issues affecting waterfowl and wetlands conservation in North America, we bring the resource to you. The DU podcast.
Chris Jennings:On today's show, we are going to do another species of waterfowl, and today is the most popular duck in North America, probably the most populous duck in North America, the mallard. Joining me today is doctor Mike Brasher, my cohost. Mike, how are you?
Mike Brasher:I'm doing well, Chris. How are
Chris Jennings:you doing today? Awesome. I am ready to talk about the mallard. So, you know, just so everyone is so familiar with the Mallard. So, you know, for 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 forty five minutes or so.
Chris Jennings:But
Mike Brasher:Yeah. I don't know if there's anything to say about it.
Chris Jennings:Yeah. Right. But then you walk in with a stack full of notes, and so this is gonna be great. So, Mike, go ahead and give us a quick introduction to the mallard. Just kind of a a real brief intro about the species, and then we'll get into the weeds.
Chris Jennings:It is, as you say,
Mike Brasher: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 we'll I'll just say here, we're not gonna get into all the the taxonomic relatedness, phylogenetic relatedness of this species. We actually had doctor Phil on an earlier episode talking extensively about this, and this is this kind of his area of expertise. So kinda go back to some of those episodes if you wanna 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.
Mike Brasher:But then, of course, through a variety of introductions, they're now pretty much found on every continent except Antarctica across the globe. So, yeah, we can get into harvest statistics and where it ranked and all that kind of stuff, but pretty much anything that we're gonna say about the mallard is that it's gonna rank at the top in terms of how intensively it's studied. It adds 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 wanna 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. I And know you mentioned you didn't wanna get real in-depth with this, but I'm gonna let you kinda share a little bit about the taxonomy.
Mike Brasher:Yeah. And and this kinda goes to this this well studied group of birds kinda called the mallard complex, the mallard clade. And and, yeah, I'm not gonna get too deep into it because quite frankly, I am not a taxonomic expert. That's where our good friend, Phil Ovetsky, comes in comes in handy. But here within North America, we can certainly touch on the most the most obvious ones.
Mike Brasher:Mallard, you know, that's the that's where we start. And American black duck, close relative to that. Mottleduck, 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 Hawaiian Islands, we have the Hawaiian duck and the the leisantile that are in that Mallard complex, and then you kinda get overseas and pick up a few others, four or five others depending on how you wanna look at the taxonomy.
Mike Brasher:But I'll stay away from that for right now. We'll just kinda 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 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 and one thing that you mentioned is it is worldwide. I mean, the mallard is, you know, distribution wise.
Chris Jennings: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 gonna see many, many mallards in urban settings, and there's a variety of reasons why that 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 their diet, their habitat needs, their nesting needs. They can nest anywhere. You can find them anywhere.
Mike Brasher:So a lot of the people that see ducks in urban environments are gonna be looking at at mallards, and so just kinda keep that in mind. We'll set those urban environments aside right now just accepting that you're gonna 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 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.
Mike Brasher:They do nest in in the coastal plain Mhmm. In Alaska. They will there's sizable populations of mallards, breeding mallards in California, Oregon, Washington, Interior, British Columbia, of course, the Great Lakes States, all across the the Northeastern US, and then and then into Eastern Canada as well. They are widely distributed across across the northern tier of North America.
Chris Jennings:And I'm sure that that's the reason for their being their abundance too, is they're, you know, really prolific. 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. Yeah.
Chris Jennings:You know? And that's one thing that I think, you know, maybe our audience overlook 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 a dry year such as this 2021, the 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 6080% 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.
Mike Brasher: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 for all of our conservation efforts.
Chris Jennings:Absolutely. And, you know, you you kind of flirted with this, you know, the breeding breeding range here. Let's 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?
Chris Jennings:How many eggs are there supposed to be? So let's kinda get into that, like, just their actual, like, the functioning of their nest, how the process works. Before we get in the actual nest, you know, let's even talk about and how you did your PhD research.
Mike Brasher:That would be my master's. Master's.
Chris Jennings:Okay. You did that on mallard breeding ecology, did you not?
Mike Brasher:I did. Specifically male mallard
Chris Jennings:breeding ecology. Yeah. So so what are the what exactly how's where how does this process start and and kinda 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 the subsequent spring. Mallards, in contrast to other species that we've talked about, like blue winged teal, mallards are a species that will will pair fairly early. They will 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 the female is far along in incubation, or otherwise, one of the pair members dies for whatever reason.
Mike Brasher: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 seventy, eighty to 80% of the mallards being 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 gonna be some males that will not find a mate. But, yeah, they 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, they will the hen will find a suitable nest site in some typically in some type of upland area. They are upland nesting ducks like most dabbling ducks in North America. However, mallards, very flexible in their nest site selection, they will they will nest over water.
Mike Brasher:They can kinda construct a little platform, actually, over water out of grasses or emergent vegetation and build nest in in those situations. They also nest frequently in human provided, human constructed structures. Nest tunnels would be
Chris Jennings:the
Mike Brasher:most common type of of nesting structure that people would would find a mallard, hen mallard nesting in, and they are 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 or primary nest site selection or however they characterize it, a lot of times they will find mallards most often in odd areas. They kinda describe them as odd areas, shrubby areas, long fence line. Flower pots. Oh, there's been some of that too.
Mike Brasher:We've found some in the the crooks or crevices of trees. You know? They're just they 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 like pintails, which are almost nest site specialists. And, of course, there's a story behind with pintails about how that is sorta one of the things that's causing their population, you know, troubles.
Mike Brasher:But but, yeah, mallards are readily adaptable in terms of their nest site selection, and so the the hen establishes a nest, creates a nest bowl, and on average, she will lay about nine eggs. That contrast with another species we've talked about, again, blue wing teal, sort of the other end of one of these spectrums. So mallards are about you know, or a larger duck, about two and a half to three pounds. And 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 Mhmm.
Mike Brasher: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 from well, the 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 she'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 ten days before they gear back up for for nesting.
Mike Brasher:But anyway, mallards are one of the most prolific re nesting species. They will they can nest up to re nest up to five times during years when there's abundant wetlands when, you know, conditions are good. Now in drought years, such as 2021, it provides us an opportunity to talk about this and how it how it affects their ecology. They're not going to re nest as often simply because they're gonna assess the habitat conditions. And in a drought landscape, they're gonna be able to sense a and detect a shortage of wetlands and whatever kind of calculus goes on in in the mind of a duck to make those decisions.
Mike Brasher:It happens, and they will curtail their re nesting quite a bit during the years when there are there are fewer wetlands. So, yeah, that kinda gets us to the to the clutch average clutch size of nine. With each of those re nests, the average clutch size decreases. And and and that that rule that's a general rule anyway. The later in the breeding season that a nest in it is initiated, the smaller the clutch size will be.
Mike Brasher:Average length of incubation for a mallard is somewhere around twenty six, twenty eight days.
Chris Jennings:What time of year are they typically getting up there to start this process? Yeah.
Mike Brasher: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. K. So we would have to be there on-site basically before the ducks arrive. Sometimes they would start arriving in very late March.
Mike Brasher:But most often, mallards are gonna be some of the first to arrive. Mallards and pintails will be among the first to venture back north. They wanna get an early start on breeding, and they will, yeah, typically get there in the in noticeable numbers in the first first week or April, and then they will start nesting in mid April if conditions are right.
Chris Jennings:Yeah. And that, you know, I wanna I kinda wanted to just go back real quick before we we move on into clutch size, because I'm sure we're gonna get pretty detailed on this. But you talked about, you know, the the initial stages of that breeding process, 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.
Chris Jennings: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 you start seeing pairs. You know? You're not seeing a flock of 20 or a flock of eight. You're seeing a 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.
Chris Jennings:You know, they they've probably seen that. So I just wanted to kinda point that out before we move on to actual clutch size and things like that. So 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 10?
Mike Brasher:Yeah. Nine or on average, nine, sometimes 10, sometimes eight eggs. Mhmm. 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.
Mike Brasher:One of the questions is, like, hatchability. What percentage of the eggs in a nest will actually hatch or fertile? That that percentage is pretty high. It's just kind of a a little tidbit. Probably over ninety, ninety five percent are gonna be fertile.
Mike Brasher:You know? So high hatchability is very rare that you it may even be higher than ninety five percent, but it's very rare that you find nests that go unhatched in in most of your dabbling and diving ducks, wood ducks, and other blackbelly or whistling ducks and other cavity nesting species may be a little bit different, when you have a situation where that nest is being parasitized and you have multiple females nesting in a in a box, you know, you can get massive clutch sizes, twenty and thirty.
Chris Jennings:Those are
Mike Brasher:pretty rare. Those type yeah. They're they're rare, but, well, it's not uncommon at all for 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, overwater 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 the exception of canvas bacton redheads. There's gonna be all sorts of exceptions to
Chris Jennings:this conversation.
Mike Brasher:There are gonna be very few instances where the eggs do not hatch. So you're gonna have nine or 10 ducklings or or fewer if it's later in the season that will hatch. And 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 or other most of the other birds that we're kinda familiar with, where they when they hatch, they are they're naked. You know? They they do not have feathers.
Mike Brasher:That's that's in contrast to the precocial birds, which do have 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 to a wetland, and, you know, are kinda guided or taken there by the hen, and they They're
Chris Jennings:all in way.
VO:Try to
Mike Brasher:catch bugs.
Chris Jennings:Yeah. And, you know, and that's 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 could that can kill the whole clutch.
Chris Jennings:I mean, it can.
Mike Brasher:Yes. The the once they hatch, the brood. Absolutely. We go from a from a clutch to a clutch of eggs to a brood of ducklings or goslings. And, yes, during those those first few days, and I forget exactly how many days, I wanna say they, you know, they have the ability to thermoregulate to some small degree pretty quick, maybe within a day or two, but but then it's not until they're maybe a week or so old that may be a little generous.
Mike Brasher:They may get there around four or five days where they develop a greater sense of thermal regulation, and they're able to kinda they are a bit more resilient to those kinda adverse weather conditions. But during those first few days, absolutely, the hen has to brood them, basically meaning that that at night or in otherwise inclement weather conditions, whether it be a snowstorm or rain, they will huddle under her and find a place, a log or or a dry area up in the vegetation, and and try to stay out of the eyesight and detection of predators, and she will protect them from those elements by getting them to kinda stuff up underneath her feathers and under her wings and pretty neat little deal. So, yes, she does brood them for those first few days. But then once they once they get to about a week or so of age, they they can do a a bit better job independently of thermoregulating. But absolutely, exposure is a common source of mortality for for ducklings.
Chris Jennings:And and as we just kinda go through this process, we're actually gonna, 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.
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Chris Jennings: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, from the time they hatch, it's gonna require somewhere between forty to sixty days for them to to, you know, to be fully feathered and and able to fly. Actually, they can typically, sometimes they can fly a little bit sooner than that. But but, yeah, about fifty days, I I'd say, is probably a good average time to fledging after 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 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 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 I'll confess.
Mike Brasher:I don't know exactly, you know, what what controls the length of time that a hen is going to stay with those ducklings. 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 kinda bugger off, you know, two weeks prior to that. So there's the she will the point is she's gonna 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 to grow?
Mike Brasher:No. It's gonna be invertebrates of all 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 that's traveling overhead or that's perched on a on a piece of vegetation. But, yeah, it's 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 all the other tissue that they need to grow and grow grow quickly.
Chris Jennings:Yeah. And and that's when the like I mentioned, the kind of the pressure's on. Yep. So we'll kind of transition into that. You know, they're trying to put on weight preparing for the migration.
Chris Jennings: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 kinda 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 the the different sexes. So 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 I said earlier that they're seasonally monogamous.
Mike Brasher:The female in in ducks in in North America, we have what's known as female biased parental care care. Pretty much the female is the only sex that cares for ducklings in in ducks here. And so basically, what that means is that the male's responsibility for any kind of any kind of care of the ducklings, I mean, it's nonexistent, but any their their parental care responsibilities begins to wane as the female progresses into incubation. And so what what my study actually did was I had radio marked males as well as the radio marked female pair, and so I 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 what are the at what point do the males depart the breeding ground, either leave the female and go seek other breeding opportunities, or completely leave the the breeding site, the breeding region, and go go ahead and start molting.
Chris Jennings:Yeah. I just wanna point out that, you know, most of the world just looks at ducks, and but doctor Mike Rasier collects visual observations.
Mike Brasher:Well, that's right. That's all we did.
Chris Jennings:Collect visual observations. I was just looking. You know, I'd look at them.
Mike Brasher:No. We observe and yes. That's right.
Chris Jennings:That's perfect. No. That was that was cool. And but, you know, in your your studies there, were you learning that maybe that male hung out a little longer than you originally thought?
Mike Brasher:We did. Our our study was 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 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 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 had been previously found. And so I don't exactly know if there was something driving that. Maybe it was an exceptionally wet year.
Mike Brasher:They had good wetland conditions, and the male was kinda gauging whether he thought there was gonna be additional re nest opportunities. So, 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 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 in our case, the study area.
Mike Brasher:And and by widely, I'm talking five to 10 miles. Sometimes we'd have to go to search for them. But then once she gets even farther into incubation, and certainly once she hatches 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 what the males do. And then females, they, if they're successful raising if they're successful hatching a clutch, they, of course, do transition into brood care, and it was not uncommon for females, we think, to actually molt their wing feathers at on the breeding grounds where they have been raising that brood.
Mike Brasher:Now, if if they nest early enough and or if their nest is destroyed or repeated nest or destroyed, then they will eventually kinda 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 gonna be happening in late summer, and then they Mallards and some of the other ducks 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 kinda hanging out, getting fat, replacing their their flight feathers, and preparing for that southward migration whenever they feel the urge to
Chris Jennings:do You know, is mallard one of those species where the young of the year quickly become, you know, that within that same year, you know, are is a hen mallard going to be expected to raise a root and nest that same year? Or is it one of those species where it's like two years old, it'll do it?
Mike Brasher:Yeah. All dabbling ducks will nest or and are capable of of breeding in their first year
Chris Jennings:First year.
Mike Brasher:Okay. 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,
Chris Jennings:you know,
Mike Brasher:three months. Yeah. Yeah. I I just was not sure. Spring.
Mike Brasher:Right? They do breed at one year of age. Mallards, blue wings, shovelers, pintails, black ducks, all those species are are are that way. And in most of the diving ducks, there's there are most of the diving ducks are gonna 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 because 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 I think that that 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.
Chris Jennings: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 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.
Chris Jennings: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 the 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 that will have already migrated to Louisiana by by by late October, maybe even earlier in some years, early early November. And meanwhile, there are still mallards left in this 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 it gets cold, versus those that really hang out at northern latitudes despite severe winter weather.
Mike Brasher:What causes those differences? We really don't know, and it's actually a pretty intriguing question that I that I think is gaining a little bit more attention, or at least it's it's it's been talked about Mhmm. A lot now as we 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 but certainly, mallards being our one of our largest duck species, our our largest dabbling duck species, it is able to pack on a lot of fat. It it has a highly flexible diet, It can basically eat anything from invertebrates to to corn or rice or wheat or peas, and that gives it ton of options of fish Yeah.
Chris Jennings:I was gonna
Mike Brasher:peanuts, you know, corns, anything. It there's very few things that Mallards will not will not eat and cannot derive some energetic or caloric value from. But during that that staging period, they are trying to pack on calories. They're consuming, you know, carbs. That's what they're after.
Mike Brasher:And so that's gonna 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.
Mike Brasher:But traditionally, when you think about large flocks of of mallards that are out across that landscape foraging feverishly to try to pack on that fat. We're talking about peas, garbanzo beans Yeah. You know, wheat, barley, those are gonna 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 thing the food resources change? And and what what are these ducks doing once they're on the wintering grounds?
Mike Brasher:I I think it's probably fair to say that we don't see noticeable changes in the in, like, the the type of nutrients that ducks, that mallards are seeking until the following spring. Mhmm. During fall, winter, and prior to spring migration, it's really carbs Yeah. Seeds, acorns, agricultural grains that they are after. Now they have to supplement that obviously with invertebrates and other other forms of of plant material to obtain their essential nutrient minerals and nutrients just like we all have to have a balanced diet.
Mike Brasher: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.
Mike Brasher:We don't need to feed them bread. So, yeah, we don't see changes to their diet until until spring, and that, again, relates to them kinda gearing up to gearing up for that breeding season egg formation. Actually, now that I say that, and I kinda listen to myself talk here, one of the things that I'm leaving out in terms of what they go through during winter is 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.
Mike Brasher:So do they do seek out protein in the form of invertebrates at that time of year as well. So I wanna make sure I didn't kinda goof up there and forget about the molt that occurs during the winter as well.
Chris Jennings:Yeah. And and just to clarify that, you know, the body molt is actually the body feathers. Yes. And they transition new feathers at that time, and but they they can still fly.
Mike Brasher:Yes. Absolutely.
Chris Jennings:And I I just wanted you to clarify that for our audience that, you know, when you think of molt, the first thing that especially me 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 kinda off guard here.
Mike Brasher:I'd have to stop and think about this to get it correct. So I'm just gonna say they go through a couple of body molts, a couple of molts of their contour feathers, their body feathers each year, and males and females differ a little bit in the timing of those of those molts, and so 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 molt and how they vary among species among species, and, you know, there are some that we there there's some thought that even that maybe ruddy ducks might go through a second wing molt on their their wintering ground. So anyway, there's some interesting things to talk about with regard to getting in into the details of molt when it happens, the different types of molt and and so forth. But, yeah, the that's why whenever you go out into a wetland during the during the winter and you see all these feathers on the water
Chris Jennings:Yep.
Mike Brasher:Well, they're going through that body molt during 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 and being the most abundant duck. Really, these things are making up a majority of a lot of people's bags. And I just wanna 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 gonna harvest near as many mallards as Arkansas, obviously.
Chris Jennings:But what is it about that habitat use during the winning area that really attracts mallards to these high abundant states.
Mike Brasher:So you you love to ask those what is it, why questions, which puts me on the on the side of having to provide a a good explanation. So let me just say there's probably a number of reasons behind this. Let me 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 gonna be related to And quite frankly, a lot of the patterns that we see now are gonna be a reflection of the sort of longer term historical patterns of migration and habitats and how they've occurred across the landscape. So when we kinda 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.
Mike Brasher: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 forests, 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 and has remained so, quite frankly, the 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 gonna find mallards, and you're gonna find mallard abundance is gonna be at a regional scale, kinda correlated with at least the historical abundance of those of that of those wetlands. Out in California, a good chunk of the mallards that they harvest in Central Valley California are gonna be locally produced. You've got mallards that will will that are locally produced in the Great Lakes that make up a good portion of their mallard harvest.
Mike Brasher:Same is gonna be the case on the in the Atlantic Flyway, the Northeastern US, where you get you get some mallard production. Those birds disproportionately contribute, you know, like, a percentage basis. If you look at the birds produced in the Northeastern US, the majority of those are gonna be harvested in 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. So 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 the stronghold.
Chris Jennings:So And you have some harvest numbers too.
Mike Brasher:Mean I do. I do. We can look at harvest, and it's gonna 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 probably it's been that way for many years and continues to be that way. When you look across the entire entire US, I don't think these numbers here account for a harvest that occurs in Canada.
Mike Brasher:Look across the entire US, on average, over the past twenty 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 but on average, we're looking at four to four and a half million mallards harvested, and half of those are gonna come from the Mississippi Flyway. About 20% of those of that is gonna come from the Central Flyway. A 20 another 20% is gonna come from the Pacific Flyway, including Alaska, and then you get about 10% or so from the Atlantic Flyway.
Mike Brasher:And if you look at the importance of mallard in the overall harvest of ducks, on average, they're gonna account for about a third of total duck harvest.
Chris Jennings:That's a lot.
Mike Brasher:So it is. It one species accounts for about a third of the total duck harvest. Now part of that is because that we have it's a it's a robust population size. If you look continentally, you're probably looking at a population size breeding population size somewhere around ten, eleven, 12,000,000 on average, And that may be even higher in in some years. And, yeah.
Mike Brasher:So it's it's an incredibly abundant duck. It has we have, you know, respectably high bag limits, at least during the liberal seasons here over the past twenty 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 and they don't always respond to my calling or 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
Chris Jennings:the case. Think there's something special to be be said about, you know, it is it's ironic that that it is the most abundant species and it is also, you know, the the most harvested species. Yet, it still holds such a, you know, I guess, a a high stature.
Mike Brasher:That's right. It doesn't hunters. So the appreciation isn't worn out, isn't eroded by its That's right. By its abundance or by its popularity or the not popularity. But, yeah, it's it's just it's commonness.
Chris Jennings:Yeah. 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.
Chris Jennings: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 some real conservation focus that 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 Interior British Columbia, Washington, Oregon, and California. There's the Midcontinent breeding stock of mallards. That will include mallards in the prairie provinces of Canada, the Northern the the prairies of The US, the Western Boreal Forest, the Great Lakes states.
Mike Brasher:And then in the then there's the eastern stock of mallards, eastern population of mallards, which is going to include everything pretty much East Of East Of The Great Lakes. Major production areas will include the Northeastern states down to about Virginia. You're gonna 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. So those three stocks of mallards are how we, in the waterfowl management community, manage mallard populations. Western mallards have been doing pretty good.
Mike Brasher:I don't have population numbers broken down by 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 Midcontinent population, that's, of course, the largest population of of mallards there, anywhere from, you know, nine to six or 7,000,000, depending on habitat conditions, whatever. But typically, you're looking at around 9,000,000, at least here in recent years.
Mike Brasher:So with 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 midcontinent. I may be a little bit off on some of those numbers, but relatively speaking, it's gonna be in the ballpark. The Midcontinent mallard population is the is the big one. And so in terms of conservation concerns, western mallards are doing doing pretty well.
Mike Brasher:Well, they're doing fine. There's no indication of any issues with with their populations right now. And then in the Midcontinent population, no issues there. Like, there's no no pressing, like, population decline that we can't necessarily understand. Now if you wanna look more regionally within that midcontinent population, you can go to the Great Lakes states.
Chris Jennings:Mhmm.
Mike Brasher: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 Great Lakes Mallards as a subset of that Midcontinent population, and then you get into the Eastern Mallard, and that's its entire kinda issue of its own. We've seen also population declines over the past ten or so years for eastern mallards, and we began to touch on that a little bit with Phil Ovetsky a couple of years ago when he was looking at the genetics of what's actually happening there 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, kinda becoming more prevalent in that eastern mallard population, and some there's also some questions about differences in productivity between mallards nesting in The US versus mallards nesting in Canada.
Mike Brasher:It's like we're seeing these population declines, what's driving it? Is it harvest? Is it reproduction? And if it's and then are there differences in reproduction between birds produced in The or birds breeding in The US and birds breeding in Canada? So, you know, when we look at mallards, the Great Lakes as well as the Eastern mallard population are the ones for which we do have some concerns, some legitimate questions, and we're trying to get at those through some targeted science.
Mike Brasher: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 kinda what's going on with with those areas, or at least for the the habitat requirements, and the type of work that we need to be doing to maximize re 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, I'll, you know, say, oh, well, shoot. We didn't we didn't talk about that. We didn't talk about that.
Chris Jennings:That's right.
Mike Brasher:We could've 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.
Mike Brasher:You bet, Chris. My my pleasure. I'd like
Chris Jennings:to thank my cohost, doctor Mike Brasher, for coming on the show and 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.
VO:Thank you for listening to this episode of the DU podcast. Be sure to rate, review, and subscribe to the show, and visit www.ducks.org/dupodcast for resources based on today's topics as well as access to more episodes. Opinions expressed by guests do not necessarily reflect those of Unlimited. Until next time. Stay tuned to the ducks.
VO:Stay tuned to the ducks.
