DU Podcast Transcript: Ep. 6 – 2019 Trends in Duck Breeding Populations Survey – Diving Duck Species

The crew discusses diving ducks and their estimated breeding population for 2019

© Michael Furtman

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 we're going to continue on with a 2019 waterfowl survey. I've got Dr. Tom Mormon, the chief scientist sitting here with me. We're going to dig into the diving ducks. We'll kick it off with redheads. Took kind of a little punch in the gut there at 27% down and a 0% change over the longterm average, which shows some steadiness but less than, well a little over 700,000 birds counted this year.

Tom Moorman: Yeah, so hunters, over the longterm the population remains pretty healthy. This year it did in fact decline as you noted, significantly at about 27% for total breeding population for redheads. Typically what we see in red heads is a lot of site fidelity, so they'll go back to the same wetland year in, year out for nesting. Same thing happens in canvasbacks. And the core of a redhead nesting tends to be Manitoba, Saskatchewan, a little bit over into Alberta. That part of southern Canada, southern prairies, is really dry this year. And so it's not to be unexpected that those birds probably forgo nesting. Some of them might stop out in the Dakotas where it's wet. And we do in fact see a pretty significant response. 40% increase in redheads in the Dakotas, for example. So there'll be some production out of the Dakotas. Redheads used more permanent wetlands, and deeper wetlands, and so some of those in Manitoba, Saskatchewan, Alberta will continue to hold a bit of water. Could be some nesting in there if the water is still up into the cattails, they'll do okay. If it is pulled down out of the cattail and there's a mudflat is probably not going to end well for that breed.

Chris Jennings: Yeah. And just to reiterate, hunters seeing down 27% from 2018 and that's not the end of the world. You know, it's not something that people should expect.

Tom Moorman: No, it's really not, and to be honest, I'm not sure as a really avid waterfowl hunter that I could tell you if I were down on Laguna Madre where redheads winter in abundance that I would notice a difference. It ultimately hinges on, as we talk about these numbers and these breeding populations, ultimately at the end of the day, your success as a hunter hinges pretty heavily on weather and whether the birds are being pushed to migrate and all those kinds of things, local habitat conditions, regional habitat conditions, lots of things factor into this. Yes, it matters if the population is high or low, but ultimately you can have a really fantastic hunt even at the worst of times in a breeding population.

Chris Jennings: That's a good point to make. Let's move on to canvasbacks. They're down 5% this year, probably indicative of the habitat in the prairies. Still up 10% from the longterm average, coming in and a little over 600,000 birds counted. You mentioned some very unique distribution of canvasbacks when we were off air. Describe that and why you're seeing that down 5%.

Tom Moorman: So the population of cans is still more or less at it's longterm average and the population is pretty healthy. This year it's down a bit. And again this is a bird that has a lot of site fidelity. This is probably the king of site fidelity-

Chris Jennings: King can.

Tom Moorman: For birds. Literally cans go back to the same wetland to nest year in, year out. And if that wetland is dry they will forgo nesting for many years. So the core of their range tends to be again southern Manitoba, southern Saskatchewan, again, the deeper wetlands. That is the area of the prairies that got dry this year and was pretty dry last year. And so when you look at these survey numbers, it leaves you scratching your head a little bit, but we see pretty negative response of number of breeding birds in southern Saskatchewan, southern Manitoba for sure. The one that I'm wrestling with a bit is an increase in birds in Alberta. My suspicion there is there's a piece of geography and very extreme southern Alberta just north of Montana called the Milk River Ridge. My guess is, I know it happens to be wet and just as is western Montana and eastern Dakotas, both the Dakotas and that part of Montana and probably southern Alberta probably picked up birds. My suspicion is though that they may not nest. They're hanging out for the summer and waiting for a better year next year, is the can strategy.

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Chris Jennings: The next species on the list and the last species we've got here, Scaup, you know greaters and lessers are counted together, correct?

Tom Moorman: They are. That's because they can't be distinguished from an aircraft and, and that's fine. What do we mostly know about greater Scaup is most of them are Arctic nesters, but some of them are down in the boreal forest. Lesser Scaup, on the other hand, are mostly in the boreal forest with some proportion of the population down in the prairies. So what do we expect for Scaup this year? Well, the boreal wetlands tend to be more stable and more predictable. They're a little drier this year in places. I don't think it's probably dry enough to impact Scaup production in the Boreal forest zone. However, in the prairies it will be plenty dry to impact that segment of the Scaup population that breeds there.

Chris Jennings: And is that where that down 10% is really coming from?

Tom Moorman: Mostly it will come out of, as we look at the survey information again, it's that southern Saskatchewan, southern Manitoba region, an area of parts of those provinces that have high densities of wetlands, some of them are deeper potholes, bigger potholes, cattail line potholes especially. Those are places that are drier this year. We don't see in this case, a lot of times when the Dakotas go where we talk about some birds dropping out and staying in the Dakotas. Well Scaup aren't very good at that. They don't really do that. They mostly will go on up into the boreal and the boreal part of the population is probably going to be okay. It's that prairie part of the population that causes us to see a 10% down swing. And you know statisticians will look at that and say, "Okay, well 10%, it's not statistically significant." So nobody should hit the panic button. The longer term issue about Scaup is their population as a whole remains 28% below the longterm average. That is significant. And we still, as a waterfowl management community, haven't quite figured out what's going on with those birds. There's lots of competing hypotheses. I think we're getting closer to having some answers, but the science is just not quite there yet.

Chris Jennings: Yeah. And that, and that could be a totally separate show one day. We could drill into Scaup and foraging habitats. And that's also a fascinating topic. Well, hey, we just wrapped up the, the total 2019 waterfowl survey and those short few shows. This is the first one you can go back, listen to hear about mallards, gadwalls, northern pintails. We went down the whole list. And any questions whatsoever, any thoughts, need any more information, check out ducks.org/ducknumbers or just visit ducks.org and we'll point you in the right direction. Tom, thanks for joining me today.

Tom Moorman: You bet, man. Appreciate it.

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. Until next time, stay tuned to the ducks.