DU Podcast Transcript: Ep. 25 – Introducing a Science-Based Approach to Duck Migration Forecasts (Part 2 of 2)

Host Dr. Mike Brasher brings in Dr. Mike Schummer to explain his current project of a weekly duck migration forecast.

Clay Baird: 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 in the wetlands conservation in North America, we bring the resource to you. The DU Podcast with your host Dr. Mike Brasher.

Mike Brasher: Today, we are again joined by Dr. Mike Schummer from the State University of New York College of Environmental Science and Forestry, but this time to discuss the recent and upcoming cold snap in the Eastern US and what it might mean for duck migration. Mike, welcome back to the show.

Mike Schummer: Thank you very much.

Mike Brasher: To get right into this, the way this works, I believe... Well, how about I just let you tell us how this works. What's the frequency with which you post these duck migration forecast? When do you start, and then when's the last one that you post for a given year?

Mike Schummer: Yeah, much to my wife's chagrin, I think I work on it Sunday afternoon and Sunday evening for the coming week and pull weather data from several key locations in the Mississippi and Atlantic Flyway or at least places that affect birds of the Mississippi and Atlantic Flyway. Then from that look at where these weather severity index thresholds are met for different species and then produce some comment on where it looks like the greatest likelihood of bird movement is going to be. We start them around the beginning of October and they go all the way until the end of January. That covers pretty much most of the waterfowl hunting seasons for the Mississippi in Atlantic Flyway on the US side at least.

Mike Schummer: We do an early season forecast, which is kind of me sticking my neck out and saying, "Hey, this is the long-term forecast, what we think the fall and winter is going to hold." We do that in October. Then sometime in November when I gain a little more confidence in what the winter is going to look like from really a diversity of folks that work in long-term seasonal forecasting, I grab information from them and pull that together and again stick my neck out and try to say what the long-term forecast is going to be. But we do this each week. The best bet for seeing what days birds are going to be moving is that weekly stuff because those come from seven day forecast and those are pretty solid nowadays.

Mike Schummer: Then we do a full season wrap up where I point out all the things that I said were going to happen that never did and vice versa, things that happened that we didn't see coming.

Mike Brasher: Yeah. This is a pretty exciting week, if you will, to have you on to talk about this because I'm here in Memphis and I know last week we had a pretty, a pretty strong cold snap. It brought some subfreezing temperatures to our area this far South. Looking at the forecast here over the coming week, I think we're going to have some additional really cold weather move into this part of the country, the Eastern US. We actually have something to talk about I think. Is that right?

Mike Schummer: Yeah, we do. I mean, Thursday-Friday looks like best bet for movement. I mean, I've even got pintails, which pintails are not... They're kind of a little bit early relative to say a mallet or a black duck. We've even got a forecasted mallet movement maybe even out of the latitude of Memphis to some places further South. Very slight movement, if any, in general. But yeah, lots of stuff going on. I would say relatively early season cold front stuff.

Mike Brasher: When you say the models indicate pintails, in some cases, will be moving out of the Memphis latitude, that doesn't mean that you're forecasting all pintails to move South of Memphis. That just means that if we had pintails in Memphis let's say last week, it would not be unexpected to see some of those move farther South, but meanwhile you might have some that are still farther North that would continue their move South. Is that a fair way to look at it?

Mike Schummer: Yeah, yeah, that's exactly it. You got to think of these birds as kind of rolling in numbers, right You're going to have some leave. If you had 10,000 in a location, maybe you lose a thousand of those birds, but that doesn't mean you don't pick up other ones especially if it's early in the season, right? What you really got to watch with this weather severity index if you do go online and look at our weekly updates is when the numbers really skyrocket, right, at a location. That's when you're going to see major movements, right? I mean, when things came into North Dakota recently... I mean, North Dakota in the coming week if it hasn't had a full mass exodus is going to be getting close to that, right, for all species other than mallards.

Mike Schummer: I mean, it indicates that mallards should be moving a little bit, but it's not that strong yet because they're big ducks that just hang on forever it seems like.

Mike Brasher: To give people a little bit of a picture of what you produced, the product that you have as a result of this, I'm actually holding a print out in my hand here and you have a series of locations. You've generated this index for, I think we said on the last show, six or seven different species because species differ in their tolerance of weather severity. You have a series of locations as far North as Churchill, Manitoba and coming as far South as Memphis, Tennessee. I don't think you have any locations farther South than Memphis, Tennessee, and we'll talk about that a little bit, the significance of that.

Mike Brasher: But you have other places like Devil's Lake, North Dakota, Columbus, Ohio, Syracuse, New York, Charlotte, North Carolina. You produced these numbers, if you will, and you've color coded them. Base on that coloration, it will indicate whether you should expect to see an increasing abundance or decreasing abundance or relatively stable abundance. The other thing that I want to emphasize here perhaps on your behalf is that these are based on long-term average relationships, right, and their effect at sort of relatively large scale. Is that a fair way to think about it as well?

Mike Schummer: Yeah, it is. I would never look at these as like a ultimate whether I'm going to have a good hunt or a bad hunt. I mean, local conditions make all the difference, right? This gives you a sense of what the coming week has to offer. We also compare these. We just started to add something this week, which I think is going to be very interesting as we go on in the years compared to last year. At this time last year, how do conditions... What do they look like and where are we regarding duck migration compared to last year? It really relativizes everything and gives us a general sense about whether we should be seeing numbers of birds in an area or decreasing.

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Mike Brasher: Is this the time of the year when you have a bit greater confidence in your ability to predict movements? Because prior to this time let's say, we knew all the birds were North, right? It's that first movement out of the North when you can have, especially when you have strong weather events, when you can have greatest confidence that you're going to see movements.

Mike Schummer: Yeah. It's largely when... When you have a whole entire season, and we're probably going to get into last year, right, where weather is up and down and up and down, and birds are just kind of milling around. That makes it really, really difficult. When there are these good strong cold fronts, it makes it difficult. The other thing I find with people is that... I'm the same way. You don't tend to remember more than like a year or two ago. This cold front that's coming is pretty good, but it's not anything overly substantial. I mean, yeah, it's going to snow in Syracuse, New York, but we're going to get like 1.4 inches. We're a place that gets like 200 inches of snow per year.

Mike Brasher: You have a long way to go before you get there.

Mike Schummer: We've got long ways to go. This is where I kind of try to temper people. I see a lot of reports of birds are on the move, birds are on the move, and I'm looking at it going, "A little bit," right? But it's the big systems that are helpful and you can really see it in the weather severity index jump. The other stuff makes it more difficult because again birds kind of trickle through. Some leave. Some show up. There's a lot of years where we don't see this mass migration where you can be out hunting a field or a marsh and it's just bird streaming over and over and over and birds coming into your decoys. I mean, everybody, we all live for those days, but we don't get that type of migration every single year. Sometimes it's just a trail.

Mike Brasher: I'm looking at the comparison to last year. You referenced that. This time last year, you are no longer generating forecasts for Churchill, Manitoba. It was already frozen out. That's the other thing. Once these northern latitudes get to... Once they exceed the threshold by some degree, everything freezes out. You no longer generate forecast for those locations. You're still generating a forecast for Churchill this year, but this time last year you weren't. Folks will probably remember last November we had some really, really cold weather and then things change. It warmed up and then we had an incredible amount of precipitation across the Eastern US.

Mike Brasher: Sort of touching on that topic, in your original publication for development of this weather severity index, you mentioned that you did not... Your index doesn't account for precipitation. As well as the index may do in predicting forecast or forecasting movements over a large scale or long timeframe, there can always be anomalous events such as unprecedented rainfall that creates habitat beyond anything we've seen in recent memory and that kind of throws a wrench into the forecast. Is that right?

Mike Schummer: Yeah, it does. It definitely does. Landscape level flooding like we saw last year. You can have a lot of snow on the ground and it can be cold, but if you've got running rivers that are three feet out of the banks at northern latitudes and they're going to be in a lot of cornfields and that's going to hold I'm going with millions of ducks at latitudes that usually have moved out of. We do have enough in these new forecasts that go beyond mallards and have all the other species in there. We have 20 that come from data from 26 locations and some of those are in river systems. We pick up some of that background in the data, some of that variation, but we can't capture every metric, right?

Mike Schummer: We went for weather because the way I look at it is you can have all kinds of food on the landscape, you can have all kinds of roosting areas and refuge and everything, but when it gets cold enough and snow enough for long enough, those birds can't stay most of the time. We went for that, but there's all kinds of things, food availability, disturbance, refugia, what ways the winds have been blowing, all types of things that are also affecting duct migration. We can't account for everything, right? I think weather was the logical one to go for.

Mike Brasher: Yeah. Well, Mike, thanks again for all the work that you've done to help us understand waterfowl migration in ways that we had not been able to before. We're able to quantify some of these factors that influence migration. It's not a perfect model. No models are, especially when we're talking about phenomena of nature, but it allows us to develop a little bit of a better understanding of the way the system works and understand how it may influence the things that we enjoy doing. I know the weather that's on the way down is exciting for a lot of people, especially the folks that are in places where the hunting season is underway. I think it's also exciting for people whose hunting season is on the doorsteps.

Mike Brasher: I would encourage folks to look into some of this information and learn a little bit more about it. We're going to try to have you on again over the winter and probably even have you on at the end of the season to do sort of a recap. We can talk about a whole host of other issues related to this, refinements to any of the models. I know you're always looking for ways to improve models and our understanding, and so there's no shortage of things that we can talk about with respect to this. Any final words from you, Mike, with respect to our discussion?

Mike Schummer: I think what I enjoy most about these weekly forecasts is we get a lot of feedback. I get emails. I get interaction with folks on social media that are thanking us for putting these out. I think in a very busy world, this is a great hunter recruitment and retention tool because the more better days we can give people and the greater possibility of them having quality hunting, I think that puts us in a lot better places as a waterfowl hunting community, especially if they're getting kids out or other family members or people that haven't waterfowl hunted before and picking a day that looks pretty good. That's sometimes tough to do by just looking at the newspaper or watching the evening news.

Mike Schummer: We try to boil that down into something that's pretty straight forward. I mean, I even put in there that, hey, it looks like Thursday-Friday is your best spot. Again, I am sticking my neck out a little bit, but it's better than not having any information out.

Mike Brasher: That's right. As long as people realize, there's so much variation in the system that no single prediction is going to be accurate every time. This is just sort of long-term what you can expect and we're applying the data as best we understand it and that's really all we can do. Mike, if people wanted to learn a little bit more about this, find some of this information, where could they do that?

Mike Schummer: Yeah, that's great. The easiest way to find us is to go to Google and just Google Schummer duck migration. It will come up right underneath the Ducks Unlimited Migration page that you all have. It's Schummer, S-C-H-U-M-M-E-R, and then duck migration. We're also on Facebook. Our lab is on Facebook and we post a lot of stuff on there regarding bird movements and that's just @ourwaterfowl. If you just put @ourwaterfowl, it'll come up right away for you. There's a lot of links on there that talk about weather and duck migration stuff as well.

Mike Brasher: Thanks again for coming on. We look forward to having you back.

Mike Schummer: Thank you very much. Appreciate it.

Mike Brasher: Thanks again to our guest today, Dr. Mike Schummer. We look forward to having him back on the podcast. I also want to thank our producer Clay Baird, and thanks to each of you for supporting Ducks Unlimited.

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.