Clay Baird: Welcome to the ducks unlimited podcast, the only podcast about all things waterfowl. From planning 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 with your host, Chris Jennings.
Chris Jennings: Today, I've got Dr Mike Brasier, and I am going to be asking some hard hitting questions from a duck hunter's perspective. It's early to mid October. People are up in Canada. Majority of the guys up there are field hunting right now, and I've heard some guys doing pretty well. Some guys kind of getting a little shaky, getting a little concerned. But the main question that I have is just as someone who is fascinated with ducks, obviously, and geese, what exactly are the ducks doing up there right now? What aspect of their life cycle are they in?
Mike Brasher: Yeah, this is an interesting time of year for ducks and for duck hunters and it's, I guess, within the waterfowl ecology world, it's broadly defined as the post breeding period. Right now, if we're talking late September, early October, we're in this almost like a a transition phase between post breeding and migration, fall migration. And it's one of the things that I think we'll try to convey as we go through a lot of these discussions is what waterfowl is doing at any one period of time is not independent of what they've just done. Whatever kind of activity they've just come out of and whatever activity or significant life cycle event they're about to go into are all connected. What they're doing now is preparing them for what they're about to do next. And so here we find ourselves in this post breeding phase right before migration, some birds are already migrating, blue-winged teals. Some of the early migrants, they're already winging their waste way South. Others are staging up at Northern latitudes. And so, I guess to frame this, to get to get a folks a proper perspective on, on what we're talking about is let's assume for the sake of this discussion that they've already completed their wing molt. Ducks will have already completed that, so we're beyond that. Most of these ducks are already flighted.
Chris Jennings: And, and one thing I just wanted to clarify there was, I'm mainly referencing the Prairie pothole region, ducks on the prairies. I don't think I said that clearly just to make sure everyone knows that.
Mike Brasher: Yeah. And so there's also other things like molt migrations that will have already occurred. We'll come back to that topic on another day. That's fascinating in itself. But right now we're in this staging period prior to fall migration for most of those species. And so, it's a pretty straight forward time of year for the ducks. They're doing a couple of things. And one of those, least for males, is they're replacing that drab basic plumage as they go into that [crosstalk 00:03:05] flightless mode, they drop all that bright plumage. And so right now those males are trying to change out of that drab plumage and regain that bright alternate breeding plumage. And the reason they're doing that and trying to do it as quick as possible is because they want to get ready to court the female. That's going to be starting up pretty soon, but they're not doing that right now. They're preparing for that and so that's one of the things that they're going through. In order to do that, they need nutrients, they need proteins and things of that nature to replace those feathers. They also need energy to fuel that process. The other really important thing that they're doing is just preparing themselves for migration. And we all know that these birds fly long, long distances and that migratory flight is an energetically costly activity. So that's really their, one of their primary focuses is gaining enough fuel reserves, if you will, to fuel that migration. Their number one goal is to eat right now. Of course, they want to survive too, right? But they're eating, they're seeking out and using those habitats that have an abundance of high energy foods, acquiring some proteins in the process. And the one thing to also keep in mind is when we look across waterfowl, we have to take into consideration all the different species and how their feeding habits in their desired habitats differ. And like for some species mallards, pinned tales, even widgeon to some extent, they're going to zero in on some of those grain fields.
Chris Jennings: They're getting the wheat, the barely, the peas.
Mike Brasher: The wheat, barley, the peas, yeah. Chickpeas, garbanzo beans, all of the field peas is another really, really highly valued type up there, food item that they go after. And so you'll see them pouring into those. But there are also those species that don't field feed so readily. They are what we might call her obligate wetland species, the bluing teal, the green-wing teal to some extent. They're actually one of those species that will field feed, but they'll also take to wetlands quite a bit. But gadwall, shovelers, and then of course you're diving ducks as well. They're not really fielding, but they're all doing the same thing. They're seeking out those high energy foods. Those wetlands that provide or fields or dry fields that provide those high energy foods. And it's this activity that we refer to, ornithology refer to is and I guess just a ecologists in general, hyperphagia, with hyper meaning a sense of heightened and phagia means to eat. So hyperphagia, they're eating a lot. That's really what they're trying to do is acquire as many calories and nutrients as they can to complete that molt and then to pack on the fat so that they can, they can make it South once they finally do start to migrate.
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Chris Jennings: It's just like the, like you see on Twitter and Instagram when the fat bear syndrome, the fat bear time of year, September, you see these pictures of big fat bears who are just stockpiling food.
Mike Brasher: It's the same-
Chris Jennings: Exact same process. Okay.
Mike Brasher: Exact same concept. Exact same concept. And it happens with fish as well. Just as there's about to go into winter, they need these fat stores to either withstand the cold temperatures or fuel migration. And that's one thing that we've seen through various studies is that, as you go from October to December, body masses of various duck species, waterfowl species will increase demonstrating that they're packing on the fat in anticipation of that migration. So that's really what they're after. Interestingly, we can talk about this sometime later. Once they get to about December, there seems to be a decline in that body mass, and there's some sort of evolutionarily or some adaptation for that. And like I said, we can talk about that a little bit later on.
Chris Jennings: He got mentioned, and I'll just go back to mention like hunters who were up in Canada now, they're seeing huge flocks of mallards, Pintos, like you said, maybe widgeon, even potentially green wings who are feeding in fields. Geese the same way. But then, look in the other direction there, there could be big flocks of gadwalls and they're working in the wetland, these little isolated wetlands or large wetlands where divers as well. And that's kind of what people are seeing. This is the process now, we've all seen these big flocks, but this is a good example for our listeners out there. Then they're looking at it and they can recognize exactly what these ducks are doing. Exactly. And I think that's a good point, just to point out that when you're out there looking and big flocks of birds, that's what they're doing. And that's great. Now we did not touch on geese. Geese are probably doing the same exact thing just to be a little bit different.
Mike Brasher: Yeah, they are. They're going to be doing exactly the same thing, but they are going to be much more attracted to those agricultural fields. It's the same thing, they're putting on putting on reserves, putting on fat reserves to fuel their migration. And so that's a... Yeah, you want to be, if you're out hunting, birds or... And this is pretty, pretty constant throughout the non-breeding period you want to be where the birds are, where the birds want to be in this time of year especially they want to be where the food is rich, where the food is energy dense, whether we're talking gadwall, teal, geese, they're all kind of after the same thing is a lot of food. And so, as they go through this sort of premigration phase, they're going to put on those fat reserves, and then another topic that we can talk about later on is kind of what happens right before they migrate. It's termed "zugunruhe". It's a German word.
Chris Jennings: Bless you.
Mike Brasher: It means migratory restlessness. It's a phenomenon. It's pretty interesting actually how they discovered it, how they tested for it and confirmed it experimentally, but it's this phenomenon where birds get restless. They literally get really antsy and right before they're about to migrate. And we can dig into some of the details on that and what controls it and kind of what triggers the transition from this hyperphagia to zugunruhe, and then the next step is-
Chris Jennings: It's probably weather related, too as well. I mean is that kind of offset it or can it be?
Mike Brasher: It's probably going to be related to that. What stimulates it at any particular point in time, I'm not certain on where the science is on that. We can look into that for you before we talk about that.
Chris Jennings: Yeah, well we're going to have to do a completely separate show on zugunruhe. That's-
Mike Brasher: But it, it's a pretty fascinating concept. I've never actually witnessed a group of birds engaging in this kind of antsy, erratic, and I shouldn't say erratic, but this sort of restless behavior. But it's pretty interesting. And so then, if you observe that and then if they're not there the next day, well they took off, they migrated.
Chris Jennings: Well that's awesome. Well, I appreciate it. I hope everyone learned a lot about what they're seeing people up on the prairies. Obviously down here we're still waiting on them down here, but now everyone knows exactly what they're seeing as far as the life cycle of birds and even some zugunruhe there.
Mike Brasher: Zugunruhe and hyperphagia. And so, for those of us that are still down South, waiting on the birds to migrate, we can engage in our own form of hyperphagia as we wait out the hot summer, it feels like it's still summer, the hot summer and fall days in our own form of hyperphagia as we watching college football and NFL and whatever else might entertain it.
Chris Jennings: I'm down with hyperphagia right now. I appreciate it, Mike. Thanks a lot.
Mike Brasher: Absolutely.
Clay Baird: 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 Ducks Unlimited. Until next time, stay tuned to the ducks.